tag:theconversation.com,2011:/africa/topics/voyager-3952/articlesVoyager – The Conversation2023-08-02T03:05:10Ztag:theconversation.com,2011:article/2108822023-08-02T03:05:10Z2023-08-02T03:05:10ZVoyager 2 has lost track of Earth. Only one antenna in the world can help it ‘phone home’<figure><img src="https://images.theconversation.com/files/540640/original/file-20230802-17534-2xhcac.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1280%2C720&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.jpl.nasa.gov/images/pia21839-voyager-in-deep-space-artist-concept">NASA / JPL-Caltech</a></span></figcaption></figure><p>In 1977, five years before ET asked to “phone home”, two robotic spacecraft began their own journey into space. </p>
<p>Almost 46 years later, after exploring the Solar System and beyond, one of those spacecraft – Voyager 2 – has lost contact with Earth.</p>
<p>All communication with Voyager 2 goes through NASA’s Deep Space Station 43, a 70-metre radio dish at the <a href="https://www.cdscc.nasa.gov/">Canberra Deep Space Communication Complex</a> operated by CSIRO. </p>
<p>Contact was lost more than a week ago. After intense efforts at NASA and here in Canberra, we have detected a faint “heartbeat” signal from the craft – and we’re confident of re-establishing full contact.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1686469699469778944"}"></div></p>
<h2>Through the Solar System and beyond</h2>
<p>NASA’s twin Voyager spacecraft – Voyager 1 and Voyager 2 – were designed to complete a “grand tour” of the Solar System, visiting the giant planets Jupiter, Saturn, Uranus and Neptune. </p>
<p>Throughout the billions of kilometres of their journeys, the Voyagers stayed in touch with Earth through the three antennas of the Deep Space Network. One is in Madrid, Spain; a second in Goldstone, California; and the third in Canberra.</p>
<p>Having completed their tasks in 1989, both Voyager 1 and 2 have long since left our Solar System behind. They are now exploring interstellar space – the space between the stars. </p>
<p>Voyager 1 is currently 24 billion kilometres from home, with Voyager 2 not far behind at 20 billion kilometres.</p>
<h2>Whispers from space</h2>
<p>On July 21, a series of planned commands sent to Voyager 2 inadvertently caused the spacecraft’s antenna to point two degrees away from Earth. As a result, the spacecraft is currently unable to receive commands or transmit any data back to Earth.</p>
<p>Mishaps like this are not uncommon in space exploration. The NASA team is expert at problem solving, and has a good track record of keeping spacecraft flying long after their prime mission has ended.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/from-the-edge-of-the-solar-system-voyager-probes-are-still-talking-to-australia-after-40-years-82512">From the edge of the Solar System, Voyager probes are still talking to Australia after 40 years</a>
</strong>
</em>
</p>
<hr>
<p>NASA’s science and engineering teams have dealt with communication drop-outs before, with both Voyagers. Their efforts have already quadrupled the planned 12-year life of the craft, so they don’t think we’ve heard the last from Voyager 2.</p>
<p>It’s an enormous achievement that we still have contact with these spacecraft at all, given their enormous distance from Earth and the relative weakness of the signal received through the big antenna dishes in Canberra. Even when Voyager 2 is pointing at Earth, its signal is already a whisper from space, billions of times weaker than the power generated by a tiny watch battery.</p>
<h2>A heartbeat 20 billion kilometres from home</h2>
<p>The last time Voyager 2 was out of contact was in March 2020, when the dish at the Canberra Deep Space Communication Complex was shut down for a scheduled 11-month upgrade project. Ahead of the shutdown, commands were sent to Voyager 2 to program the spacecraft to maintain operations without needing to hear from Earth for an extended period.</p>
<p>Canberra’s Deep Space Station 43 is the only antenna in the world that can communicate directly with both Voyagers. Its sister stations in the northern hemisphere are unable to “see” Voyager 2, because Earth is in the way.</p>
<p>Since Voyager 2’s antenna was tweaked off target, we have been using Deep Space Station 43 to listen intently for any signal. Eventually this effort paid off, with the detection of the craft’s carrier tone – a “heartbeat” indicating Voyager 2 is still transmitting.</p>
<p>Now attempts will be made to relay commands to Voyager 2 and tell it to re-orient its antenna towards Earth.</p>
<p>If those attempts fail, Voyager 2 is already programmed to use the Sun and the bright star Canopus to re-orient itself several times each year. The next scheduled reset will occur on October 15, which should automatically enable communications to resume.</p>
<h2>Into interstellar space</h2>
<p>The Canberra team feels a very close connection to this distant traveller. We have been with it on every step of its journey so far, and plan to continue to provide mission support for however long the mission lasts.</p>
<p>Voyager 2 was launched on August 20 1977 and reached Jupiter in July 1979, a few months after Voyager 1. It proceeded to Saturn for a flyby of the ringed planet in 1981, and then had encounters with Uranus in 1986 and Neptune in August 1989, ending the so-called “grand tour”.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/after-45-years-the-5-billion-year-legacy-of-the-voyager-2-interstellar-probe-is-just-beginning-188077">After 45 years, the 5-billion-year legacy of the Voyager 2 interstellar probe is just beginning</a>
</strong>
</em>
</p>
<hr>
<p>As both spacecraft were in good health, they were given an extended mission to reach the edge of our Solar System, where the influence of the Sun’s energy ends. The Voyagers are now in the “clear air” of interstellar space and can, for the first time, make direct measurements of this environment.</p>
<p>The <a href="https://www.nature.com/articles/s41550-019-0928-3">data they have returned</a> are changing our understanding of the Universe. The teams at NASA and here in Canberra are confident there is more science and discoveries to come, when Voyager 2 once again phones home.</p><img src="https://counter.theconversation.com/content/210882/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Glen Nagle does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The Voyager 2 spacecraft is 20 billion kilometres away and has lost track of Earth. A radio dish near Canberra is the only channel for re-establishing communication.Glen Nagle, Outreach Manager, Canberra Deep Space Communication Complex, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2056402023-05-17T01:37:13Z2023-05-17T01:37:13ZShowy, impractical to play, and looks like the 1980s: why we keep falling for the keytar<p>This year, Perth synth-metal band Voyager finally succeeded in their long-running dream of representing Australia at Eurovision. After multiple attempts, they were directly chosen by the post-Australia Decides <a href="https://www.sbs.com.au/news/article/australias-voyager-though-to-eurovision-grand-final-how-did-they-get-into-the-contest/wancd9kyf">“committious mysterious”</a> and hopped on the long haul to Liverpool. </p>
<p>They did not disappoint, making it through to the final. Their song, Promise, was voted ninth by an adoring fanbase. Not bad indeed!</p>
<p>But what even is synth-metal?</p>
<p>Traditionally, synths in metal, particularly onstage, were generally frowned upon and seen as a sign of inauthenticity. In the 1990s, I swore allegiance to baggy clothes, instrumental techno and synthesisers. The black t-shirt-wearing grunge fans worshipped guitar riffs, screamo lyrics and mosh pits. </p>
<p>We kept in our lanes and followed the rules.</p>
<p>Voyager’s proud embrace of synthesisers reject this rather 1990s separation and return metal to the melodic pomp of Van Halen’s <a href="https://www.youtube.com/watch?v=SwYN7mTi6HM">Jump</a> or Europe’s <a href="https://www.youtube.com/watch?v=9jK-NcRmVcw">The Final Countdown</a>. The band can still rock hard, but like the taco ad says, “Why not both?”</p>
<p>If you were coming to the finals fresh, Promise followed the classic Eurovision three-act strategy to maximum effect. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/GSoy_mJMlMY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Beginning with synthesised staccato pulses playing rich harmonic progressions, it feels like a classic Euro-trance anthem, not unlike the Swedish winner, <a href="https://www.youtube.com/watch?v=BE2Fj0W4jP4">Tattoo</a>. We find lead singer Daniel Estrin onstage driving his 1980s convertible, hair half-shaved and half in luscious locks. His mysterious passenger, bathed in neon – a red keytar. </p>
<h2>A what? I haven’t seen one of those in ages!</h2>
<p>The word “keytar” is a portmanteau of keyboard and guitar. It looks like a keyboard but is hung around the neck and played like a guitar.</p>
<p>The first verse of Voyager’s song begins its ascent, “if you haven’t ever done anything like this before then you haven’t been alive”. </p>
<p>I suppose not – I really need to get out with my keytar more often, this looks like fun. </p>
<p>The keytar stays in its seat as the band rolls through stadium rock, synchronised guitar swings, hard drum hits and distorted guitar stabs. In the second act, Voyager are now death metal. </p>
<p>It’s deep growls, drop-tuned power riffs, and scattergun kick drums. The audience’s collective mind explodes. </p>
<p>After one more melodic pre-chorus, it’s time for the third and final act. With one boot threatening to scratch the duco of the car, the lead guitar solo lifts us up to melodic rock heaven. </p>
<p>But wait. For the second half, Estrin grabs the red keytar and joins in. He throttles its neck and finishes with a lightning-fast arpeggiated flourish that ELO’s Jeff Lynne would be proud of. </p>
<p>The finale repeats and ascends until we all rise to metal nirvana. A quick, traditional pyro-pop ends it all. That was truly genius! </p>
<p>The power of the keytar is restored.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/eurovision-under-the-shadow-of-war-how-the-2023-contest-highlighted-humanitarianism-empathy-and-solidarity-205468">Eurovision under the shadow of war: how the 2023 contest highlighted humanitarianism, empathy and solidarity</a>
</strong>
</em>
</p>
<hr>
<h2>An instrument of mixed feelings</h2>
<p>The keytar tends to be loved or loathed. Created in the late 1970s and popularised throughout the 1980s, it looks like a product of its time. </p>
<p>Made of shiny plastic, shaped like the future, it’s showy and rather impractical to play. </p>
<p>If you want to play chords, it is easier to play them on a horizontal keyboard, like a traditional synthesiser. </p>
<p>The primary advantage of the keytar is portability and pose-striking. Like its distant ancestor, the piano accordion, a player is free to move around, finally free of the horizontal grip of gravity. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/6TltAi_XbHY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Most guitarists thought of it as a joke, whereas new-wave synth players saw it as a cool accessory to their modern sound and fashion-forward hair. </p>
<p>This was the future, as viewed from 1980.</p>
<p>One early adoptor was Edgar Winter. His instrumental track <a href="https://www.youtube.com/watch?v=P8f-Qb-bwlU">Frankenstein</a> topped the Billboard chart in 1973. A multi-instrumentalist who played guitar, sax, percussion and keyboards, he took conventional synths and simply added shoulder straps to wear them like a guitar. </p>
<p>While this is a cool look, it is not great for the spine.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/P8f-Qb-bwlU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>The first manufactured keytars were released in the late 1970s, the <a href="https://en.wikipedia.org/wiki/George_Mattson_(synthesizer_inventor)#The_Syntar">PMS Syntar</a> (see what they did there?) being exhibited at Atlanta’s 1979 NAMM show (National Association of Music Merchants). </p>
<p>It was a time of extremely contrasting genres that nevertheless all had synthesisers at the core of their sound. More traditional progressive rock acts such as Yes vied with the new vision of electropunk by Devo. Glam metal bands adopted its look, while synth-driven electrofunk artists could overturn conventional rock theatrics. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/j_QLzthSkfM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>The fall and the rise</h2>
<p>The new, standardised MIDI language created an ecosystem that allowed musos to access any synth from any manufacturer, rather than being beholden to one. This quickly resulted in cheaper, easier-to-use synthesisers becoming more widely accessible, leading to the home recording boom we all enjoy today.</p>
<p>This bastion of the future soon became as passe as the flat-tops, mohawks and mullets of the people who played them. As we moved into the 1990s, the joyous excesses of 1980s pop bands would soon be seen as daggy. Replaced by faceless DJs, flannel-wearing rockers and choreographed dancers, it was time to sell your keytar or put it into storage.</p>
<p>But after a couple of decades of respectful silence, the humble keytar slowly began to re-emerge. Lady Gaga led the charge on her Fame Ball Tour in 2009. The keytar does make sense for such a look-driven, 1980s-influenced artist. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/PecJgs75RxQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>So all hail the keytarists of the world. Thank you Thomas Dolby, A-Ha and Dave Stewart. Respect to Chick Korea, Herbie Hancock and Prince. To Muse, Arcade Fire, John Paul Jones and Lady Gaga, may you shred in space, without a hair in place. Thank you Voyager!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/is-eurovision-finally-cool-that-depends-on-your-definition-cool-theory-expert-explains-205600">Is Eurovision finally cool? That depends on your definition – 'cool theory' expert explains</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/205640/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul (Mac) McDermott does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Perth synth-metal band Voyager was voted ninth in the world at the 2023 Eurovisions. Was the keytar the secret to their success?Paul (Mac) McDermott, Lecturer in Contemporary Music, Sydney Conservatorium of Music, University of Sydney, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1883392022-08-11T16:56:30Z2022-08-11T16:56:30ZCrypto platforms say they’re exchanges, but they’re more like banks<figure><img src="https://images.theconversation.com/files/478364/original/file-20220809-15110-oy8izt.jpg?ixlib=rb-1.1.0&rect=8%2C73%2C5455%2C3358&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Crypto trading platforms Celsius and Voyager filed for bankruptcy in July 2022, suspending all withdrawals, swaps and transfers between accounts and leaving users’ assets trapped inside their platforms.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/crypto-platforms-say-they-re-exchanges--but-they-re-more-like-banks" width="100%" height="400"></iframe>
<p>There is a well-known saying shared by both crypto experts and skeptics: “Not your keys, not your coins.” The phrase, <a href="https://cointelegraph.com/news/antonopoulos-your-keys-your-bitcoin-not-your-keys-not-your-bitcoin">popularized by Bitcoin entrepreneur Andreas Antonopoulos</a>, refers to how the contents of a crypto wallet are the property of whoever has access to that wallet’s digital “keys.”</p>
<p>This means that unless you personally have the keys to your crypto assets and store them offline, you are vulnerable to hacks, scams and bankruptcies. <a href="https://www.ic3.gov/Media/News/2022/220718.pdf">The endless stream of crypto scams has been well documented</a>. So have the <a href="https://web3isgoinggreat.com/?theme=hack">security breaches</a> — and not to mention the <a href="https://www.reuters.com/technology/how-big-is-bitcoins-carbon-footprint-2021-05-13/">eye-popping carbon emissions</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-digital-economys-environmental-footprint-is-threatening-the-planet-126636">The digital economy's environmental footprint is threatening the planet</a>
</strong>
</em>
</p>
<hr>
<p>Of course, offline storage requires an extra level of understanding, technological sophistication and inconvenience. Enter crypto exchanges like Coinbase and Crypto.com, which offer simple, convenient platforms for users to buy and sell cryptocurrencies and NFTs. </p>
<p>However, <a href="https://www.bloomberg.com/news/articles/2022-06-26/crypto-winter-why-this-bitcoin-bear-market-is-different-from-the-past">the crypto crash</a> has revealed that these firms are not just exchanges — they are more like banks. Except defunct crypto exchanges like <a href="https://www.cnn.com/2022/07/14/business/celsius-bankruptcy/index.html">Celsius Network</a> and <a href="https://dfr.vermont.gov/consumer-alert/voyager-digital-files-chapter-11-bankruptcy">Voyager Digital</a> were only banks if you read the fine print. Most customers, of course, did not. </p>
<figure class="align-center ">
<img alt="A hand holding a cellphone with the Coinbase app open on it in front of a laptop with the Coinbase website open" src="https://images.theconversation.com/files/478362/original/file-20220809-9831-cb7fie.jpg?ixlib=rb-1.1.0&rect=16%2C0%2C3607%2C2221&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/478362/original/file-20220809-9831-cb7fie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=368&fit=crop&dpr=1 600w, https://images.theconversation.com/files/478362/original/file-20220809-9831-cb7fie.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=368&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/478362/original/file-20220809-9831-cb7fie.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=368&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/478362/original/file-20220809-9831-cb7fie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=463&fit=crop&dpr=1 754w, https://images.theconversation.com/files/478362/original/file-20220809-9831-cb7fie.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=463&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/478362/original/file-20220809-9831-cb7fie.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=463&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Crypto exchanges like Coinbase and Crypto.com offer simple, convenient platforms for users to buy and sell cryptocurrencies and NFTs.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Who needs deposit insurance?</h2>
<p>Until very recently, crypto exchanges were all the rage. They had <a href="https://www.hollywoodreporter.com/business/digital/cryptocurrency-spend-big-on-hollywood-names-to-gain-trust-1235019008/">A-list celebrity spokespeople</a>, <a href="https://www.latimes.com/business/story/2021-11-16/crypto-staples">stadium naming rights</a> and <a href="https://www.ctvnews.ca/politics/poilievre-personally-holds-investment-in-bitcoin-as-he-promotes-crypto-to-canadians-1.5907615">public endorsements by major politicians</a>. </p>
<p>Crypto exchange companies market themselves as platforms for users to buy and sell crypto. But they also function like stockbrokers and, more concerningly, their core business models quite closely resemble banking.</p>
<p>Traditional exchanges, like the New York Stock Exchange, rarely go bankrupt. And since they do not offer account services, if they do go bankrupt their clients are not on the hook for any losses. Brokerage firms, like Wealthsimple, do sometimes go bankrupt, but <a href="https://www.finra.org/investors/alerts/if-brokerage-firm-closes-its-doors">their clients’ portfolios are held in the client’s own name</a> and, accordingly, may simply be transferred to a different broker. In the event of fraud, <a href="https://www.cipf.ca/cipf-coverage/about-cipf-coverage#coverage">both Canada</a> and <a href="https://www.sipc.org/for-investors/what-sipc-protects">the United States</a> provide automatic insurance for lost assets. </p>
<p>Banks, like the Royal Bank of Canada, take on more risks and <a href="https://fred.stlouisfed.org/series/BKFTTLA641N">fail more often</a>. Because banks use customer deposits to make loans, <a href="https://corporatefinanceinstitute.com/resources/knowledge/other/bank-run/">banks are vulnerable to runs</a>. This is why most high-income countries — <a href="https://www.cdic.ca/what-happens-in-a-failure/">including Canada</a> — have deposit insurance and regulate banking more than other financial services.</p>
<p>Herein lies the problem. Companies like Celsius and Voyager <a href="https://www.investvoyager.com/app/the-broker-model/">marketed themselves as both exchanges and brokers</a>, so that is how their apps appeared. But if anyone were to read the <a href="https://celsius.network/terms-of-use">terms and conditions</a>, it would be clear that they were actually uninsured, quasi-banks. </p>
<h2>Risks in crypto-banking</h2>
<p>In companies like Celsius and Voyager, customers’ accounts were not held separately in their own wallets, but rather <a href="https://www.investvoyager.com/useragreement">held in a pool owned by the platform</a>. The platform would use this pool of money to make loans (often to other crypto firms) or to engage in its own speculative investing (often in crypto assets). When depositors cashed out, they were paid from the pool, which was able to cover normal on-demand withdrawals, but did not have enough cash to handle everyone pulling out simultaneously. </p>
<p>Sound familiar? </p>
<figure class="align-center ">
<img alt="A stack of bitcoins sit in front of the logo for cyptocurrency company Voyager" src="https://images.theconversation.com/files/478365/original/file-20220809-16047-qqm53q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/478365/original/file-20220809-16047-qqm53q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/478365/original/file-20220809-16047-qqm53q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/478365/original/file-20220809-16047-qqm53q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/478365/original/file-20220809-16047-qqm53q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/478365/original/file-20220809-16047-qqm53q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/478365/original/file-20220809-16047-qqm53q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Crypto giant Voyager lied to their clients about being insured by the Federal Deposit Insurance Corporation (FDIC).</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>When crypto prices collapsed, <a href="https://www.cnbc.com/2022/07/19/what-happens-to-my-funds-if-a-crypto-exchange-goes-bankrupt.html">these firms’ loans went belly up</a> and some were forced to suspend withdrawals. When Celsius filed for <a href="https://www.uscourts.gov/services-forms/bankruptcy/bankruptcy-basics/chapter-11-bankruptcy-basics">Chapter 11 bankruptcy</a>, their <a href="https://www.coindesk.com/business/2022/07/18/celsius-bankruptcy-filings-hint-retail-customers-will-bear-brunt-of-its-failure/">depositors learned their accounts were worthless</a>, having been gambled away by the company. </p>
<p>These firms deliberately obscured this reality to their clients. In Voyager’s case, they <a href="https://www.cbsnews.com/news/voyager-fdic-insurance-federal-reserve/">outright lied about being FDIC-insured</a>. Snake-oil salesmen from these companies convinced <a href="https://twitter.com/celsiusnetwork/status/1384156564013993996">their customers that regulated banks were the problem</a>, only to learn exactly why those regulations exist in the first place. </p>
<p>To make matters worse, <a href="https://www.cnbc.com/2022/08/03/voyager-ceo-made-millions-in-stock-sales-in-2021.html">the lack of transparency in crypto markets makes it quite easy for executives and developers to dump their positions long before they suspend withdrawals</a>. By the time customers realize their money is gone, those responsible have cashed out with a tidy profit. </p>
<h2>The future of decentralized finance</h2>
<p>So where do we go from here? </p>
<p>At the micro level, the answers are obvious. <a href="https://www.sec.gov/reportspubs/investor-publications/divisionsmarketregbdguidehtm.html#V">Crypto exchanges should be regulated in the same manner as brokers</a>. Client assets must be held separately and securely, with clear rules on risk exposure in the firms’ own trading. </p>
<p>Crypto assets themselves should be clearly designated as securities, and therefore subject to oversight. Exchange platforms should be required to hold sufficient cash in government-issued currency. If this sounds like it violates the ethos of decentralized finance, that’s because it should.</p>
<p>The macro level is trickier. Post-2008, we have demonized the big banks and fetishized technology. Crypto enthusiasts claim Wall Street is only in it for itself, and they are right. But they’ve recreated the same system, only it’s even riskier. </p>
<p>The late arrivals to the crypto party — the ones now holding the bag — <a href="https://www.npr.org/2022/07/26/1112439917/amid-the-hype-they-bought-crypto-near-its-peak-now-they-cope-with-painful-losses">are not the wealthy investing class</a>. <a href="https://www.marketplace.org/2022/06/09/when-a-cryptocurrency-you-never-heard-of-drains-your-life-savings/">They are regular people</a>, rightly distrustful of banks and, by extension, our institutions, and are desperately searching for ways to shield themselves from <a href="https://theconversation.com/a-summer-of-discontent-why-public-sector-workers-are-preparing-to-strike-in-b-c-186808">skyrocketing inflation</a>.</p>
<p>Rebuilding that trust takes time and energy. It takes a willingness to deal with the inequities caused by a rising cost of living and an extractive financial system. And, crucially, it takes effective regulation. If it looks like a bank and behaves like a bank, it needs to be treated like a bank.</p><img src="https://counter.theconversation.com/content/188339/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>William D. O'Connell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Because cryptocurrency exchange platforms act more like banks, they should be subject to increased oversight to protect clients’ assets.William D. O'Connell, PhD Candidate, Political Science, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1775132022-05-25T13:46:19Z2022-05-25T13:46:19ZWhat the Voyager space probes can teach humanity about immortality and legacy as they sail through space for trillions of years<figure><img src="https://images.theconversation.com/files/464877/original/file-20220523-11-z3t5y6.jpg?ixlib=rb-1.1.0&rect=0%2C9%2C799%2C589&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Scientists expect the Voyager spacecraft to outlive Earth by at least a trillion years.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:PIA17036_Voyager_the_Explorer.jpg#/media/File:PIA17036_Voyager_the_Explorer.jpg">NASA/JPL-CalTech</a></span></figcaption></figure><p>Voyager 1 is the farthest human-made object from Earth. After sweeping by Jupiter, Saturn, Uranus and Neptune, it is now almost <a href="https://voyager.jpl.nasa.gov/mission/status/">15 billion miles (24 billion kilometers) from Earth</a> in interstellar space. Both Voyager 1 and its twin, Voyager 2, carry little pieces of humanity in the form of their <a href="https://voyager.jpl.nasa.gov/golden-record/">Golden Records</a>. These messages in a bottle include spoken greetings in 55 languages, sounds and images from nature, an album of recordings and images from numerous cultures, and a written message of welcome from Jimmy Carter, who was U.S. president <a href="https://theconversation.com/voyager-golden-records-40-years-later-real-audience-was-always-here-on-earth-79886">when the spacecraft left Earth in 1977</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/464881/original/file-20220523-23-zyjgnu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A golden colored record with 'The Sounds of Earth' written in the center." src="https://images.theconversation.com/files/464881/original/file-20220523-23-zyjgnu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/464881/original/file-20220523-23-zyjgnu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/464881/original/file-20220523-23-zyjgnu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/464881/original/file-20220523-23-zyjgnu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/464881/original/file-20220523-23-zyjgnu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/464881/original/file-20220523-23-zyjgnu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/464881/original/file-20220523-23-zyjgnu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Each Voyager spacecraft carries a Golden Record containing two hours of sounds, music and greetings from around the world. Carl Sagan and other scientists assumed that any civilization advanced enough to detect and capture the record in space could figure out how to play it.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:The_Sounds_of_Earth_-_GPN-2000-001976.jpg">NASA/Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>The Golden Records were built to last a billion years in the environment of space, but in a recent analysis of the paths and perils these explorers may face, astronomers calculated that they <a href="https://www.space.com/predicting-voyager-golden-records-distant-future">could exist for trillions of years</a> without coming remotely close to any stars.</p>
<p>Having spent my career in the field of <a href="https://sipa.fiu.edu/people/faculty/religious-studies/hurchingson.james.html">religion and science</a>, I’ve thought a lot about how spiritual ideas intersect with technological achievements. The incredible longevity of the Voyager spacecraft presents a uniquely tangible entry point into exploring ideas of immortality.</p>
<p>For many people, immortality is the everlasting existence of a soul or spirit that follows death. It can also mean the continuation of one’s legacy in memory and records. With its Golden Record, each Voyager provides such a legacy, but only if it is discovered and appreciated by an alien civilization in the distant future. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/464879/original/file-20220523-15-ck32f0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="People in black standing around a coffin at a gravesite." src="https://images.theconversation.com/files/464879/original/file-20220523-15-ck32f0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/464879/original/file-20220523-15-ck32f0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/464879/original/file-20220523-15-ck32f0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/464879/original/file-20220523-15-ck32f0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/464879/original/file-20220523-15-ck32f0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/464879/original/file-20220523-15-ck32f0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/464879/original/file-20220523-15-ck32f0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Many religions espouse some form of life after death.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/outdoor-shot-of-funeral-royalty-free-image/104305070?adppopup=true">RubberBall Productions/Brand X Pictures via Getty Images</a></span>
</figcaption>
</figure>
<h2>Life after death</h2>
<p>Religious beliefs about immortality are numerous and diverse. Most religions foresee a postmortem career for a personal soul or spirit, and these range from everlasting residence among the stars to reincarnation. </p>
<p>The ideal eternal life for many Christians and Muslims is to abide forever in God’s presence in heaven or paradise. Judaism’s teachings about what happens after death are less clear. In the Hebrew Bible, the dead are mere “shades” in a darkened place called Sheol. Some rabbinical authorities <a href="https://jewishencyclopedia.com/articles/12697-resurrection">give credence to the resurrection of the righteous</a> and even to the eternal status of souls.</p>
<p>Immortality is not limited to the individual. It can be collective as well. For many Jews, the <a href="https://library.yctorah.org/2016/05/the-importance-of-the-land-of-israel/">final destiny of the nation of Israel or its people</a> is of paramount importance. Many Christians anticipate a <a href="https://www.britannica.com/topic/Kingdom-of-God">future general resurrection</a> of all who have died and the coming of the kingdom of God for the faithful.</p>
<p>Jimmy Carter, whose message and autograph are immortalized in the Golden Records, is a progressive Southern Baptist and a living example of religious hope for immortality. Now <a href="https://healthcare.utah.edu/healthfeed/postings/2015/08/082015_jimmy.carter.php">battling brain cancer</a> and approaching centenarian status, he has thought about dying. Following his diagnosis, Carter <a href="https://www.washingtonpost.com/politics/2019/11/04/jimmy-carter-says-he-is-completely-ease-with-death/">concluded in a sermon</a>: “It didn’t matter to me whether I died or lived. … My Christian faith includes complete confidence in life after death. So I’m going to live again after I die.”</p>
<p>It is plausible to conclude that the potential of an alien witnessing the Golden Record and becoming aware of Carter’s identity billions of years in the future would offer only marginal additional consolation for him. Carter’s knowledge in his ultimate destiny is a measure of his deep faith in the immortality of his soul. In this sense, he likely represents people of numerous faiths. </p>
<h2>Secular immortality</h2>
<p>For people who are secular or nonreligious there is little solace to be found in an appeal to the continuing existence of a soul or spirit following one’s death. Carl Sagan, who came up with the idea for the Golden Records and led their development, wrote of the afterlife: “<a href="https://www.goodreads.com/quotes/1221453-i-would-love-to-believe-that-when-i-die-i">I know of nothing to suggest that it is more than just wishful thinking</a>.” He was more saddened by thoughts of missing important life experiences – like seeing his children grow up – than fearful about the expected annihilation of his conscious self with the death of his brain.</p>
<p>For those like Sagan there are other possible options for immortality. They include <a href="https://gizmodo.com/why-freezing-yourself-is-a-terrible-way-to-achieve-immo-1552142674">freezing and preserving the body for future physical resurrection</a> or <a href="https://www.wsj.com/articles/will-your-uploaded-mind-still-be-you-11568386410">uploading one’s consciousness and turning it into a digital form</a> that would long outlast the brain. Neither of these potential paths to physical immortality has proved to be feasible yet.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/cEzcFXRKHUw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Golden Records contain a snapshot of Earth and humanity.</span></figcaption>
</figure>
<h2>The Voyagers and legacy</h2>
<p>Most people, whether secular or religious, want the actions they do while alive to bear <a href="https://doi.org/10.1016/j.jaging.2004.08.002">continuing meaning into the future as their fruitful legacy</a>. People want to be remembered and appreciated, even cherished. Sagan summed it up nicely: “To live in the hearts we leave behind <a href="https://www.goodreads.com/quotes/1029590-to-live-in-the-hearts-we-leave-behind-is-to">is to live forever</a>.” </p>
<p>With Voyagers 1 and 2 estimated to exist for more than a trillion years, they are about as immortal as it gets for human artifacts. Even before the Sun’s expected demise when it runs out of fuel in about 5 billion years, all living species, mountains, seas and forests <a href="https://theconversation.com/the-sun-wont-die-for-5-billion-years-so-why-do-humans-have-only-1-billion-years-left-on-earth-37379">will have long been obliterated</a>. It will be as if we and all the marvelous and extravagant beauty of planet Earth never existed – a devastating thought to me.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/464878/original/file-20220523-21-ofwph8.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A chart showing the path of Voyager 1 spiraling off into the distance." src="https://images.theconversation.com/files/464878/original/file-20220523-21-ofwph8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/464878/original/file-20220523-21-ofwph8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=199&fit=crop&dpr=1 600w, https://images.theconversation.com/files/464878/original/file-20220523-21-ofwph8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=199&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/464878/original/file-20220523-21-ofwph8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=199&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/464878/original/file-20220523-21-ofwph8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=250&fit=crop&dpr=1 754w, https://images.theconversation.com/files/464878/original/file-20220523-21-ofwph8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=250&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/464878/original/file-20220523-21-ofwph8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=250&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Voyager 1’s path, in white, has taken the craft well past the orbits of the outer planets into interstellar space, where aliens may someday come across the relic of humanity.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Voyager_1_skypath_1977-2030.png#/media/File:Voyager_1_skypath_1977-2030.png">NASA/JPL via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>But in the distant future, the two Voyager spacecraft will still be floating in space, awaiting discovery by an advanced alien civilization for whom the messages on the Golden Records were intended. Only those records will likely remain as testimony and legacy of Earth, a kind of objective immortality.</p>
<p>Religious and spiritual people can find solace in the belief that God or an afterlife waits for them after death. For the secular, hoping that someone or something will remember humanity, any wakeful and appreciative aliens will have to do.</p><img src="https://counter.theconversation.com/content/177513/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Edward Huchingson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A professor of religion and science explains different views on immortality, from the religious perspective of President Jimmy Carter to the scientific, secular take of Carl Sagan.James Edward Huchingson, Professor Emeritus and Lecturer in Religion and Science, Florida International UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1379672020-05-20T12:15:15Z2020-05-20T12:15:15ZTo safely explore the solar system and beyond, spaceships need to go faster – nuclear-powered rockets may be the answer<figure><img src="https://images.theconversation.com/files/335879/original/file-20200518-83367-yrk119.jpg?ixlib=rb-1.1.0&rect=0%2C17%2C3952%2C3119&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Over the last 50 years, a lot has changed in rocketry. The fuel that powers spaceflight might finally be changing too. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/rocket-orbiting-the-earth-royalty-free-illustration/533327609?adppopup=true">CSA-Printstock/DIgital Vision Vectors via Getty Images</a></span></figcaption></figure><p>With dreams of Mars on the minds <a href="https://www.nasa.gov/topics/moon-to-mars/lunar-gateway">of both NASA</a> and <a href="https://www.vox.com/2018/11/2/18053424/elon-musk-tesla-spacex-boring-company-self-driving-cars-saudi-twitter-kara-swisher-decode-podcast">Elon Musk</a>, long-distance crewed missions through space are coming. But you might be surprised to learn that modern rockets don’t go all that much faster than the rockets of the past.</p>
<p>There are a lot of reasons that a faster spaceship is a better one, and nuclear-powered rockets are a way to do this. They offer many benefits over traditional fuel-burning rockets or modern solar-powered electric rockets, but there have been only <a href="https://www.energy.gov/ne/nuclear-reactor-technologies/space-power-systems/next-generation-radioisotope-generators">eight U.S. space launches</a> carrying nuclear reactors in the last 40 years.</p>
<p>However, in 2019 the <a href="https://www.space.com/trump-nuclear-spacecraft-launch-guidelines.html">laws regulating nuclear space flights changed</a> and work has already begun on this next generation of rockets. </p>
<h2>Why the need for speed?</h2>
<p>The first step of a space journey involves the use of launch rockets to get a ship into orbit. These are the large fuel-burning engines people imagine when they think of rocket launches and are not likely to go away in the foreseeable future due to the constraints of gravity.</p>
<p>It is once a ship reaches space that things get interesting. To escape Earth’s gravity and reach deep space destinations, ships need additional acceleration. This is where nuclear systems come into play. If astronauts want to explore anything farther than the Moon and perhaps Mars, they are going to need to be going very very fast. Space is <a href="https://www.youtube.com/watch?v=Iy7NzjCmUf0&t=178s">massive</a>, and <a href="https://www.youtube.com/watch?v=zR3Igc3Rhfg">everything is far away</a>.</p>
<p>There are two reasons faster rockets are better for long-distance space travel: safety and time.</p>
<p>Astronauts on a trip to Mars would be <a href="https://www.space.com/41887-mars-radiation-too-much-for-astronauts.html">exposed to very high levels of radiation</a> which can cause serious <a href="https://www.asc-csa.gc.ca/eng/sciences/osm/radiation.asp">long-term health problems such as cancer and sterility</a>. Radiation shielding can help, but it is extremely heavy, and the longer the mission, the more shielding is needed. A better way to reduce radiation exposure is to simply get where you are going quicker.</p>
<p>But human safety isn’t the only benefit. As space agencies probe farther out into space, it is important to get data from unmanned missions as soon as possible. It took <a href="https://voyager.jpl.nasa.gov/mission/science/neptune/">Voyager-2 12 years just to reach Neptune</a>, where it snapped some incredible photos as it flew by. If Voyager-2 had a faster propulsion system, astronomers could have had those photos and the information they contained years earlier. </p>
<p>Speed is good. But why are nuclear systems faster?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/335875/original/file-20200518-83367-1x6b8r7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/335875/original/file-20200518-83367-1x6b8r7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/335875/original/file-20200518-83367-1x6b8r7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=487&fit=crop&dpr=1 600w, https://images.theconversation.com/files/335875/original/file-20200518-83367-1x6b8r7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=487&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/335875/original/file-20200518-83367-1x6b8r7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=487&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/335875/original/file-20200518-83367-1x6b8r7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=613&fit=crop&dpr=1 754w, https://images.theconversation.com/files/335875/original/file-20200518-83367-1x6b8r7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=613&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/335875/original/file-20200518-83367-1x6b8r7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=613&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Saturn V rocket was 363 feet tall and mostly just a gas tank.</span>
<span class="attribution"><a class="source" href="http://heroicrelics.org/info/saturn-v/saturn-v-general.html">Mike Jetzer/heroicrelics.org</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Systems of today</h2>
<p>Once a ship has escaped Earth’s gravity, there are three important aspects to consider when comparing any propulsion system:</p>
<ul>
<li>Thrust – how fast a system can accelerate a ship</li>
<li>Mass efficiency – how much thrust a system can produce for a given amount of fuel</li>
<li>Energy density – how much energy a given amount of fuel can produce</li>
</ul>
<p>Today, the most common propulsion systems in use are chemical propulsion – that is, regular fuel-burning rockets – and solar-powered electric propulsion systems.</p>
<p><a href="https://www.grc.nasa.gov/www/k-12/airplane/rocket.html">Chemical propulsion systems</a> provide a lot of thrust, but chemical rockets aren’t particularly efficient, and rocket fuel isn’t that energy-dense. The Saturn V rocket that took astronauts to the Moon produced <a href="https://en.wikipedia.org/wiki/Saturn_V#cite_note-30">35 million Newtons of force</a> at liftoff and <a href="https://www.space.com/18422-apollo-saturn-v-moon-rocket-nasa-infographic.html">carried 950,000 gallons of fuel</a>. While most of the fuel was used in getting the rocket into orbit, the limitations are apparent: It takes a lot of heavy fuel to get anywhere.</p>
<p>Electric propulsion systems generate thrust using electricity produced from solar panels. The most common way to do this is to use an electrical field to accelerate ions, such as in the <a href="https://www.grc.nasa.gov/WWW/hall/overview/overview.htm">Hall thruster</a>. These devices are <a href="https://www.nasa.gov/pdf/501329main_TA02-ID_rev3-NRC-wTASR.pdf">commonly used to power satellites</a> and can have more than five times higher mass efficiency than chemical systems. But they produce much less thrust – <a href="https://www.grc.nasa.gov/WWW/hall/overview/overview.htm">about three Newtons</a>, or only enough to accelerate a car from 0-60 mph in about two and a half hours. The energy source – the Sun – is essentially infinite but becomes less useful the farther away from the Sun the ship gets.</p>
<p>One of the reasons nuclear-powered rockets are promising is because they offer incredible energy density. The uranium fuel used in nuclear reactors has an energy density that is <a href="https://en.wikipedia.org/wiki/Energy_density">4 million times higher</a> than hydrazine, a typical chemical rocket propellant. It is much easier to get a small amount of uranium to space than hundreds of thousands of gallons of fuel.</p>
<p>So what about thrust and mass efficiency?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/335877/original/file-20200518-83348-1mwpqh4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/335877/original/file-20200518-83348-1mwpqh4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/335877/original/file-20200518-83348-1mwpqh4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=477&fit=crop&dpr=1 600w, https://images.theconversation.com/files/335877/original/file-20200518-83348-1mwpqh4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=477&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/335877/original/file-20200518-83348-1mwpqh4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=477&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/335877/original/file-20200518-83348-1mwpqh4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=600&fit=crop&dpr=1 754w, https://images.theconversation.com/files/335877/original/file-20200518-83348-1mwpqh4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=600&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/335877/original/file-20200518-83348-1mwpqh4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=600&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The first nuclear thermal rocket was built in 1967 and is seen in the background. In the foreground is the protective casing that would hold the reactor.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Nuclear_thermal_rocket#/media/File:NERVA_XE_nuclear_rocket_engine_being_transported_to_test_stand_-_GPN-2002-000143.jpg">NASA/Wikipedia</a></span>
</figcaption>
</figure>
<h2>Two options for nuclear</h2>
<p>Engineers have designed two main types of nuclear systems for space travel. </p>
<p>The first is called <a href="https://www.nasa.gov/directorates/spacetech/game_changing_development/Nuclear_Thermal_Propulsion_Deep_Space_Exploration">nuclear thermal propulsion</a>. These systems are very powerful and moderately efficient. They use a small nuclear fission reactor – similar to those found in nuclear submarines – to heat a gas, such as hydrogen, and that gas is then accelerated through a rocket nozzle to provide thrust. Engineers from NASA estimate that a mission to Mars powered by nuclear thermal propulsion would be <a href="https://www.popularmechanics.com/space/moon-mars/a18345717/nasa-ntp-nuclear-engines-mars/">20%-25% shorter than a trip on a chemical-powered rocket</a>. </p>
<p>Nuclear thermal propulsion systems are more than <a href="https://www.energy.gov/ne/articles/6-things-you-should-know-about-nuclear-thermal-propulsion">twice as efficient as chemical propulsion systems</a> – meaning they generate twice as much thrust using the same amount of propellant mass – and can deliver <a href="https://gameon.nasa.gov/gcd/files/2018/02/FS_NTP_180213.pdf">100,000 Newtons of thrust</a>. That’s enough force to get a car from 0-60 mph in about a quarter of a second.</p>
<p>The second nuclear-based rocket system is called nuclear electric propulsion. <a href="https://www.nasa.gov/directorates/spacetech/niac/2019_Phase_I_Phase_II/SPEAR_Probe/">No nuclear electric systems have been built yet</a>, but the idea is to use a high-power fission reactor to generate electricity that would then power an electrical propulsion system like a Hall thruster. This would be very efficient, about <a href="https://www.popularmechanics.com/space/moon-mars/a18345717/nasa-ntp-nuclear-engines-mars/">three times better than a nuclear thermal propulsion system</a>. Since the nuclear reactor could create a lot of power, many individual electric thrusters could be operated simultaneously to generate a good amount of thrust. </p>
<p>Nuclear electric systems would be the best choice for extremely long-range missions because they don’t require solar energy, have very high efficiency and can give relatively high thrust. But while nuclear electric rockets are extremely promising, there are still a lot of <a href="https://www.nasa.gov/directorates/spacetech/niac/2019_Phase_I_Phase_II/SPEAR_Probe/">technical problems to solve</a> before they are put into use. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/335876/original/file-20200518-83393-1ygu5b7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/335876/original/file-20200518-83393-1ygu5b7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/335876/original/file-20200518-83393-1ygu5b7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/335876/original/file-20200518-83393-1ygu5b7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/335876/original/file-20200518-83393-1ygu5b7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/335876/original/file-20200518-83393-1ygu5b7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/335876/original/file-20200518-83393-1ygu5b7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/335876/original/file-20200518-83393-1ygu5b7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An artist’s impression of what a nuclear thermal ship built to take humans to Mars could look like.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Nuclear_thermal_rocket#/media/File:Orion_docked_to_Mars_Transfer_Vehicle.jpg">John Frassanito & Associates/Wikipedia</a></span>
</figcaption>
</figure>
<h2>Why aren’t there nuclear powered rockets yet?</h2>
<p>Nuclear thermal propulsion systems have been studied since the 1960s but have not yet flown in space. </p>
<p><a href="https://aerospace.csis.org/wp-content/uploads/2019/02/NSC-25-Scientific-or-Technological-Experiements-with-Possible-Large-Scale-Adverse-Environmental-Effects-and-Launch-of-Nuclear-Weapons-into-Space.pdf">Regulations</a> first imposed in the U.S. in the 1970s essentially required case-by-case examination and approval of any nuclear space project from multiple government agencies and explicit approval from the president. Along with a <a href="https://www.csis.org/analysis/what-does-trump-administrations-new-memorandum-mean-nuclear-powered-space-missions">lack of funding for nuclear rocket system research</a>, this environment prevented further improvement of nuclear reactors for use in space. </p>
<p>That all changed when the Trump administration issued a <a href="https://www.whitehouse.gov/presidential-actions/presidential-memorandum-launch-spacecraft-containing-space-nuclear-systems/">presidential memorandum</a> in August 2019. While upholding the need to keep nuclear launches as safe as possible, the new directive allows for nuclear missions with lower amounts of nuclear material to <a href="https://www.csis.org/analysis/what-does-trump-administrations-new-memorandum-mean-nuclear-powered-space-missions">skip the multi-agency approval process</a>. Only the sponsoring agency, like NASA, for example, needs to certify that the mission meets safety recommendations. Larger nuclear missions would go through the same process as before.</p>
<p>Along with this revision of regulations, <a href="https://spacenews.com/final-fiscal-year-2019-budget-bill-secures-21-5-billion-for-nasa/">NASA received US$100 million in the 2019 budget</a> to develop nuclear thermal propulsion. DARPA is also developing a <a href="https://breakingdefense.com/2020/02/darpa-doubles-dough-for-nuclear-powered-cislunar-rocket/">space nuclear thermal propulsion system</a> to enable national security operations beyond Earth orbit. </p>
<p>After 60 years of stagnation, it’s possible a nuclear-powered rocket will be heading to space within a decade. This exciting achievement will usher in a new era of space exploration. People will go to Mars and science experiments will make new discoveries all across our solar system and beyond.</p>
<p>[<em>You’re too busy to read everything. We get it. That’s why we’ve got a weekly newsletter.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybusy">Sign up for good Sunday reading.</a> ]</p><img src="https://counter.theconversation.com/content/137967/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Iain Boyd receives funding from the following sources, none of it is related to space propulsion:
Office of Naval Research
Lockheed-Martin
Northrop-Grumman
L3-Harris</span></em></p>An update of 50-year-old regulations has kickstarted research into the next generation of rockets. Powered by nuclear fission, these new systems could be the key to faster, safer exploration of space.Iain Boyd, Professor of Aerospace Engineering Sciences, University of Colorado BoulderLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1209452019-08-14T12:32:30Z2019-08-14T12:32:30ZA brief astronomical history of Saturn’s amazing rings<figure><img src="https://images.theconversation.com/files/287419/original/file-20190808-144892-1u8fsji.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">With giant Saturn hanging in the blackness and sheltering Cassini from the Sun's blinding glare, the spacecraft viewed the rings as never before.</span> <span class="attribution"><a class="source" href="https://www.nasa.gov/multimedia/imagegallery/image_feature_1202.html">NASA/JPL/Space Science Institute</a></span></figcaption></figure><p>Many dream of what they would do had they a time machine. Some would travel 100 million years back in time, when dinosaurs roamed the Earth. Not many, though, would think of taking a telescope with them, and if, having done so, observe Saturn and its rings.</p>
<p>Whether our time-traveling astronomer would be able to observe Saturn’s rings is debatable. Have the rings, in some shape or form, existed since the beginnings of the solar system, 4.6 billion years ago, or are they a more recent addition? Had the rings even formed when the <a href="https://theconversation.com/more-bad-news-for-dinosaurs-chicxulub-meteorite-impact-triggered-global-volcanic-eruptions-on-the-ocean-floor-91053">Chicxulub asteroid</a> wiped out the dinosaurs?</p>
<p><a href="https://dornsife.usc.edu/cf/faculty-and-staff/faculty.cfm?pid=1063926">I am a space scientist</a> with a passion for teaching physics and astronomy, and Saturn’s rings have always fascinated me as they tell the story of how the eyes of humanity were opened to the wonders of our solar system and the cosmos.</p>
<h2>Our view of Saturn evolves</h2>
<p>When Galileo first observed Saturn through his telescope in 1610, he was still basking in the fame of <a href="https://www.forbes.com/sites/briankoberlein/2016/01/07/galileos-discovery-of-jupiters-moons-and-how-it-changed-the-world/#dd6cc0f46f07">discovering the four moons of Jupiter</a>. But Saturn perplexed him. Peering at the planet through his telescope, it first looked to him as a planet with two very large moons, then as a lone planet, and then again through his newer telescope, in 1616, as a planet with arms or handles.</p>
<p>Four decades later, <a href="https://www.britannica.com/biography/Christiaan-Huygens">Christiaan Huygens</a> first suggested that Saturn was a ringed planet, and what Galileo had seen were different views of Saturn’s rings. Because of the 27 degrees in the tilt of Saturn’s rotation axis relative to the plane of its orbit, the rings appear to tilt toward and away from Earth with the 29-year cycle of Saturn’s revolution about the Sun, giving humanity an ever-changing view of the rings.</p>
<p>But what were the rings made of? Were they solid disks as some suggested? Or were they made up of smaller particles? As more structure became apparent in the rings, as more gaps were found, and as the motion of the rings about Saturn was observed, astronomers realized that the rings were not solid, and were perhaps made up of a large number of moonlets, or small moons. At the same time, estimates for the thickness of the rings went from Sir William Herschel’s 300 miles in 1789, to Audouin Dollfus’ much more precise <a href="http://solarviews.com/eng/saturnbg.htm">estimate of less than two miles</a> in 1966. </p>
<p>Astronomers understanding of the rings changed dramatically with the <a href="https://solarsystem.nasa.gov/missions/pioneer-11/in-depth/">Pioneer 11</a> and twin Voyager missions to Saturn. <a href="https://voyager.jpl.nasa.gov/assets/images/galleries/images-voyager-took/saturn/6bg.jpg">Voyager’s now famous photograph of the rings</a>, backlit by the Sun, showed for the first time that what appeared as the vast A, B and C rings in fact comprised millions of smaller ringlets. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/287555/original/file-20190809-144868-1oi82mi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/287555/original/file-20190809-144868-1oi82mi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/287555/original/file-20190809-144868-1oi82mi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/287555/original/file-20190809-144868-1oi82mi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/287555/original/file-20190809-144868-1oi82mi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/287555/original/file-20190809-144868-1oi82mi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=589&fit=crop&dpr=1 754w, https://images.theconversation.com/files/287555/original/file-20190809-144868-1oi82mi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=589&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/287555/original/file-20190809-144868-1oi82mi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=589&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Voyager 2 false color image of Saturn’s B and C rings showing many ringlets.</span>
<span class="attribution"><a class="source" href="https://voyager.jpl.nasa.gov/assets/images/galleries/images-voyager-took/saturn/6bg.jpg">NASA</a></span>
</figcaption>
</figure>
<p>The Cassini mission to Saturn, having spent over a decade orbiting the ringed giant, gave planetary scientists even more spectacular and surprising views. The magnificent ring system of Saturn is between 10 meters and one kilometer thick. The combined mass of its particles, which are 99.8% ice and most of which are less than one meter in size, is about 16 quadrillion tons, less than 0.02% the mass of Earth’s Moon, and less than half the mass of Saturn’s moon <a href="https://doi.org/10.1126/science.aat2965">Mimas</a>. This has led some scientists to speculate whether the rings are a result of the breakup of one of Saturn’s moons or the capture and breakup of a stray comet. </p>
<h2>The dynamic rings</h2>
<p>In the four centuries since the invention of the telescope, rings have also been discovered around <a href="https://doi.org/10.1007/978-0-387-73981-6_4">Jupiter</a>, <a href="https://www.universetoday.com/19288/uranus-rings/">Uranus</a> and <a href="https://www.universetoday.com/21635/rings-of-neptune/">Neptune</a>, the giant planets of our solar system. The reason why the giant planets are adorned with rings and Earth and the other rocky planets are not was first proposed by Eduard Roche, a French astronomer in 1849. </p>
<p>A moon and its planet are always in a gravitational dance. Earth’s moon, by pulling on opposite sides of the Earth, causes the ocean tides. Tidal forces also affect planetary moons. If a moon ventures too close to a planet, these forces can overcome the gravitational “glue” holding the moon together and tear it apart.
This causes the moon to break up and spread along its original orbit, forming a ring. </p>
<p>The <a href="https://www.britannica.com/science/Roche-limit">Roche limit</a>, the minimum safe distance for a moon’s orbit, is approximately 2.5 times the planet’s radius from the planet’s center. For enormous Saturn, this is a distance of 87,000 kilometers above its cloud tops and matches the location of Saturn’s outer F ring. For Earth, this distance is less than 10,000 kilometers above its surface. An asteroid or comet would have to venture very close to the Earth to be torn apart by tidal forces and form a ring around the Earth. Our own Moon is a very safe 380,000 kilometers away.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/287560/original/file-20190809-144873-yojp3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/287560/original/file-20190809-144873-yojp3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=253&fit=crop&dpr=1 600w, https://images.theconversation.com/files/287560/original/file-20190809-144873-yojp3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=253&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/287560/original/file-20190809-144873-yojp3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=253&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/287560/original/file-20190809-144873-yojp3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=318&fit=crop&dpr=1 754w, https://images.theconversation.com/files/287560/original/file-20190809-144873-yojp3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=318&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/287560/original/file-20190809-144873-yojp3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=318&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">NASA’s Cassini spacecraft about to make one of its dives between Saturn and its innermost rings as part of the mission’s grand finale.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/image-feature/illustration-of-cassini-spacecrafts-grand-finale-dive">NASA/JPL-Caltech</a></span>
</figcaption>
</figure>
<p>The thinness of planetary rings is caused by their ever-changing nature. A ring particle whose orbit is tilted with respect to the rest of the ring will eventually collide with other ring particles. In doing so, it will lose energy and settle into the plane of the ring. Over millions of years, all such errant particles either fall away or get in line, leaving only the very thin ring system people observe today.</p>
<p>During the last year of its mission, the Cassini spacecraft dived repeatedly through the 7,000 kilometer gap between the clouds of Saturn and its inner rings. These unprecedented observations made one fact very clear: <a href="https://doi.org/10.1126/science.aat3760">The rings are constantly changing</a>. Individual particles in the rings are continually jostled by each other. Ring particles are steadily raining down onto Saturn.</p>
<p>The shepherd moons Pan, Daphnis, Atlas, Pandora and Prometheus, measuring between eight and 130 kilometers across, quite literally shepherd the ring particles, <a href="https://doi.org/10.1126/science.aat2349">keeping them in their present orbits</a>. Density waves, caused by the motion of shepherd moons within the rings, jostle and reshape the rings. Small moonlets are forming from ring particles that coalesce together. All this indicates that the rings are ephemeral. Every second <a href="https://doi.org/10.1126/science.aat2382">up to 40 tons of ice from the rings</a> rain down on Saturn’s atmosphere. That means the rings may last only several tens to hundreds of millions of years. </p>
<p>Could a time-traveling astronomer have seen the rings 100 million years ago? One indicator for the age of the rings is their dustiness. Objects exposed to the dust permeating our solar system for long periods of time grow dustier and darker. </p>
<p>Saturn’s rings are extremely bright and dust-free, seeming to indicate that they <a href="https://www.scientificamerican.com/article/how-old-are-saturns-rings-the-debate-rages-on/">formed anywhere from 10 to 100 million years ago</a>, if astronomers’ understanding of how icy particles gather dust is correct. One thing is for certain. The rings our time-traveling astronaut would have seen would have looked very different from the way they do today. </p>
<p><em>This story has been corrected to reflect that it was Christiaan Huygens, not Giovanni Cassini, who first suggested that Saturn had rings.</em></p>
<p>[ <em>Like what you’ve read? Want more?</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=likethis">Sign up for The Conversation’s daily newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/120945/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vahe Peroomian does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Although the rings of Saturn may look like a permanent fixture of the planet, they are ever-changing. New analyses of the rings reveal how and when they were made, from what and whether they’ll last.Vahe Peroomian, Associate Professor of Physics and Astronomy, USC Dornsife College of Letters, Arts and SciencesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1085072018-12-10T18:55:58Z2018-12-10T18:55:58ZAustralia is still listening to Voyager 2 as NASA confirms the probe is now in interstellar space<figure><img src="https://images.theconversation.com/files/249627/original/file-20181210-76968-fmrjil.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Both Voyagers are now in interstellar space.</span> <span class="attribution"><a class="source" href="https://voyager.jpl.nasa.gov/assets/images/galleries/illustrations/PIA17462.jpg">NASA</a></span></figcaption></figure><p>NASA has confirmed that <a href="https://voyager.jpl.nasa.gov/mission/spacecraft/">Voyager 2</a> has joined its twin to become only the second spacecraft to enter interstellar space – where the Sun’s flow of material and magnetic field no longer affect its surroundings. The slightly faster <a href="https://science.nasa.gov/science-news/science-at-nasa/2013/12sep_voyager1">Voyager 1 entered interstellar</a> space in August 2012.</p>
<p>Voyager 2 is about 18 billion kilometres from Earth and still sending back data that are picked up by radio telescopes in Australia.</p>
<p>Mission scientists had been closely monitoring the spacecraft for signs that it had exited the <a href="https://www.nasa.gov/mission_pages/sunearth/science/Heliosphere.html">heliosphere</a>, a protective bubble created by the Sun as we move through our galaxy.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-detections-of-gravitational-waves-brings-the-number-to-11-so-far-107962">New detections of gravitational waves brings the number to 11 – so far</a>
</strong>
</em>
</p>
<hr>
<p>Data from Voyager 2 indicate an increase in the rate of cosmic rays hitting the spacecraft’s detectors. These fast-moving particles are known to originate outside our solar system. </p>
<p>Voyager 1 experienced a similar increase about three months before it crossed the <a href="https://www.britannica.com/science/heliopause">heliopause</a>, the boundary of the heliosphere.</p>
<p>Scientists for Voyager 2 detected a steep drop in the speed of solar wind particles on November 5, and no solar wind flow at all in the spacecraft’s environment since then. This makes them confident the spacecraft has entered interstellar space.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249621/original/file-20181210-76989-z933hb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249621/original/file-20181210-76989-z933hb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249621/original/file-20181210-76989-z933hb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249621/original/file-20181210-76989-z933hb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249621/original/file-20181210-76989-z933hb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249621/original/file-20181210-76989-z933hb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249621/original/file-20181210-76989-z933hb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249621/original/file-20181210-76989-z933hb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This artist’s concept shows Voyager and the outer layers of our solar bubble, or heliosphere, and nearby interstellar space.</span>
<span class="attribution"><a class="source" href="https://voyager.jpl.nasa.gov/galleries/illustrations/#gallery-5">NASA/JPL-Caltech, NASA/JPL-Caltech Photojournal</a></span>
</figcaption>
</figure>
<h2>Still operational, just</h2>
<p>Unfortunately not all of Voyager 2’s instruments are still operational. Its on-board data recorder failed many years ago, leaving the spacecraft with no option other than to transmit all of its data back to Earth in real time.</p>
<p>This means that if the spacecraft isn’t being tracked, its data aren’t being received and will be lost forever.</p>
<p>NASA’s Canberra Deep Space Communication Complex (<a href="https://www.cdscc.nasa.gov/">CDSCC</a>), operated by CSIRO, has been providing command, telemetry and control for the twin Voyager spacecraft since their launch in 1977. This is part of its role as one of three tracking stations for NASA’s Deep Space Network. The other two are Goldstone in California and Madrid in Spain.</p>
<p>Communicating with Voyager 2 is challenging due to its location in the southern part of the Solar System, and its extreme distance from Earth (roughly 120 times that between the Sun and the Earth).</p>
<p>Voyager 2 transmits with a power of just 20 watts. By the time the signal reaches Earth nearly 16.5 hours later, it’s billions of times weaker than the power of a watch battery.</p>
<h2>Only Australia is listening</h2>
<p>Because of their location in the Southern Hemisphere and their large antennas, CDSCC and CSIRO’s Parkes radio telescope are the only facilities in the world that can contact the spacecraft.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249623/original/file-20181210-76965-1ltw4x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249623/original/file-20181210-76965-1ltw4x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249623/original/file-20181210-76965-1ltw4x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249623/original/file-20181210-76965-1ltw4x0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249623/original/file-20181210-76965-1ltw4x0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249623/original/file-20181210-76965-1ltw4x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249623/original/file-20181210-76965-1ltw4x0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249623/original/file-20181210-76965-1ltw4x0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Parkes radio telescope.</span>
<span class="attribution"><span class="source">CSIRO</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>To capture as much scientifically valuable data as possible during this crucial period in Voyager 2’s mission, NASA engaged CSIRO’s 64-metre Parkes radio telescope to combine forces with CDSCC’s 70-metre antenna, Deep Space Station 43 (DSS43).</p>
<p>After a week of testing, on November 8 the Parkes radio telescope started tracking Voyager 2 for 11 hours a day - the entire period it is above the local horizon. CDSCC’s DSS43 is also tracking Voyager 2 for a number of hours, both before and after Parkes, to expand the available observation time. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249625/original/file-20181210-76959-5a4btv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249625/original/file-20181210-76959-5a4btv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249625/original/file-20181210-76959-5a4btv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249625/original/file-20181210-76959-5a4btv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249625/original/file-20181210-76959-5a4btv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249625/original/file-20181210-76959-5a4btv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249625/original/file-20181210-76959-5a4btv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249625/original/file-20181210-76959-5a4btv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">CDSCC’s 70-metre antenna, Deep Space Station 43.</span>
<span class="attribution"><span class="source">CSIRO</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The data these two giant dishes are receiving will provide an enormous amount of new scientific information about this previously unsampled region of space.</p>
<p>The Parkes radio telescope has had a long partnership with the Voyager 2 mission. This will be the fourth time the telescope will have tracked the spacecraft. Parkes will continue partnering with CDSCC until late February to track Voyager 2.</p>
<h2>Where no spacecraft has gone before</h2>
<p>Both Voyager spacecraft have achieved far more than the science team on Earth could have ever expected. Launched in 1977, their <a href="https://voyager.jpl.nasa.gov/mission/">prime mission</a> was to investigate the four giant planets of our Solar System: Jupiter, Saturn, Uranus, and Neptune.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249616/original/file-20181210-76962-1uuq6p6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249616/original/file-20181210-76962-1uuq6p6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249616/original/file-20181210-76962-1uuq6p6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=726&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249616/original/file-20181210-76962-1uuq6p6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=726&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249616/original/file-20181210-76962-1uuq6p6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=726&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249616/original/file-20181210-76962-1uuq6p6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=912&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249616/original/file-20181210-76962-1uuq6p6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=912&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249616/original/file-20181210-76962-1uuq6p6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=912&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Farewell shot of crescent Uranus as Voyager 2 departs. January 25, 1986. Range 966,000 km (600,000 miles)</span>
<span class="attribution"><a class="source" href="https://voyager.jpl.nasa.gov/galleries/images-voyager-took/uranus/#gallery-7">NASA</a></span>
</figcaption>
</figure>
<p>Voyager 1 and 2 both flew by Jupiter and Saturn, and a favourable planetary alignment allowed Voyager 2 to add Uranus and Neptune to its journey. Voyager 2 is the only spacecraft ever to have visited these two gas giant worlds.</p>
<h4>Voyager 2’s journey across the Solar System</h4>
<ul>
<li>20 August 1977 – Launched from Earth at Cape Canaveral</li>
<li>July 1979 – fly by Jupiter</li>
<li>August 1981 – fly by Saturn </li>
<li>January 1986 – fly by Uranus</li>
</ul>
<p>Since the Neptune encounter in 1989, both spacecraft have been on an extended mission through the outer regions of the Sun’s magnetic bubble, the heliosphere.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249617/original/file-20181210-76989-q4b2na.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249617/original/file-20181210-76989-q4b2na.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249617/original/file-20181210-76989-q4b2na.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=552&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249617/original/file-20181210-76989-q4b2na.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=552&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249617/original/file-20181210-76989-q4b2na.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=552&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249617/original/file-20181210-76989-q4b2na.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=694&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249617/original/file-20181210-76989-q4b2na.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=694&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249617/original/file-20181210-76989-q4b2na.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=694&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Neptune’s Great Dark Spot, accompanied by white high-altitude clouds.</span>
<span class="attribution"><a class="source" href="https://voyager.jpl.nasa.gov/galleries/images-voyager-took/neptune/#gallery-7">NASA</a></span>
</figcaption>
</figure>
<p>While their cameras were turned off long ago, the spacecraft continue to return data from several instruments that are collecting information on the Sun’s magnetic field:</p>
<ul>
<li>the distribution of hydrogen within the outer heliosphere</li>
<li>the composition and direction of the solar wind and interstellar cosmic rays</li>
<li>and the strength of radio emissions that are thought to be originating at the heliopause.</li>
</ul>
<p>To conserve power and operate them for as long as possible, mission planners have been turning off various instruments. </p>
<p>However, it’s likely that by 2025, only one science instrument will still be operating and then once it’s switched off, only the transmitter will be on and returning engineering data into the early 2030s. At that point, they will fall silent, no longer able to communicate with Earth.</p>
<h2>The next stop</h2>
<p>Racing through interstellar space, both spacecraft will continue on their respective trajectories, Voyager 1 at 61,198kph (16.999km per second) and Voyager 2 at 55,347kph (15.374km per second).</p>
<p>Even at that speed, covering more than 1.4 million kilometres each day, neither spacecraft will come close to another star for at least another 40,000 years.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-what-existed-before-the-big-bang-did-something-have-to-be-there-to-go-boom-103742">Curious Kids: What existed before the Big Bang? Did something have to be there to go boom?</a>
</strong>
</em>
</p>
<hr>
<p>The Voyager mission continues, orbiting the Milky Way galaxy every 225 million years and potentially encountering other star systems along the way.</p>
<p>Each spacecraft carries a <a href="https://voyager.jpl.nasa.gov/golden-record/">golden record</a> with images, music and information about planet Earth and its inhabitants. It’s a message in a bottle thrown into a vast cosmic ocean.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249618/original/file-20181210-76986-1nfeuts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249618/original/file-20181210-76986-1nfeuts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249618/original/file-20181210-76986-1nfeuts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=753&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249618/original/file-20181210-76986-1nfeuts.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=753&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249618/original/file-20181210-76986-1nfeuts.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=753&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249618/original/file-20181210-76986-1nfeuts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=947&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249618/original/file-20181210-76986-1nfeuts.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=947&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249618/original/file-20181210-76986-1nfeuts.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=947&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Golden Record cover shown with its extraterrestrial instructions.</span>
<span class="attribution"><a class="source" href="https://voyager.jpl.nasa.gov/golden-record/golden-record-cover/">NASA/JPL</a></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/108507/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>CSIRO and NASA are jointly funding use of the Parkes Telescope for Voyager 2 tracking</span></em></p>Voyager 2 launched in 1977 and visited all four gas giants in our Solar System. It’s now almost 18 billion kilometres from Earth and has finally joined its twin in interstellar space.Douglas Bock, Director of Astronomy and Space Science, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/825122017-08-18T05:03:33Z2017-08-18T05:03:33ZFrom the edge of the Solar System, Voyager probes are still talking to Australia after 40 years<figure><img src="https://images.theconversation.com/files/182362/original/file-20170817-16233-1tfxoku.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Both Voyager spacecraft are only in communication with Earth via a Canberra tracking station.</span> <span class="attribution"><span class="source">NASA/JPL</span></span></figcaption></figure><p>This month marks 40 years since NASA launched the two Voyager space probes on their mission to explore the outer planets of our Solar System, and Australia has been helping the US space agency keep track of the probes at every step of their epic journey.</p>
<p>CSIRO operates NASA’s tracking station in Canberra, a set of four radio telescopes, or dishes, known as the Canberra Deep Space Communication Complex (<a href="https://www.cdscc.nasa.gov/">CDSCC</a>).</p>
<p>It’s one of three tracking stations spaced around the globe, which form the <a href="https://deepspace.jpl.nasa.gov/">Deep Space Network</a>. The other two are at <a href="https://www.gdscc.nasa.gov/">Goldstone</a>, in California, and <a href="https://www.mdscc.nasa.gov/index.php?ChangeLang=en">Madrid</a>, in Spain. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182364/original/file-20170817-16209-lr9vy4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182364/original/file-20170817-16209-lr9vy4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182364/original/file-20170817-16209-lr9vy4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=718&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182364/original/file-20170817-16209-lr9vy4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=718&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182364/original/file-20170817-16209-lr9vy4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=718&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182364/original/file-20170817-16209-lr9vy4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=902&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182364/original/file-20170817-16209-lr9vy4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=902&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182364/original/file-20170817-16209-lr9vy4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=902&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Canberra Deep Space Communication Complex (CDSCC).</span>
<span class="attribution"><span class="source">CSIRO</span></span>
</figcaption>
</figure>
<p>Between them they provide NASA, and other space exploration agencies, with continuous, two-way radio communication coverage to every part of the Solar System. </p>
<hr>
<p><em><strong>Read more:</strong>
<a href="https://theconversation.com/water-water-everywhere-in-our-solar-system-but-what-does-that-mean-for-life-76315">Water, water, everywhere in our Solar system but what does that mean for life?</a></em></p>
<hr>
<p>Four decades on and the Australian tracking station is now the only one with the right equipment and position to be able to communicate with both of the probes as they continue to push back the boundaries of deep space exploration.</p>
<h2>The launch of Voyagers</h2>
<p>The <a href="https://www.jpl.nasa.gov/voyager/mission/">Voyagers’ primary purpose</a> was to fly by Jupiter and Saturn. If all the scientific objectives were met at Saturn, then Voyager 2 would be targeted to continue on to Uranus and Neptune.</p>
<p>At each planetary encounter – running on power equivalent to the light bulb in your refrigerator – the Voyagers would transmit photographs and scientific data back to Earth before being accelerated towards their next target by the planet’s gravity, like a slingshot.</p>
<p>Timed to take advantage of a favourable alignment of the outer planets not expected to recur for another 175 years, Voyager 2 launched first on August 20, 1977, followed by Voyager 1 on September 5. Although launched second, Voyager 1 was sent on a faster trajectory and was timed to arrive at Jupiter ahead of Voyager 2. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182365/original/file-20170817-16222-2j23u0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182365/original/file-20170817-16222-2j23u0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182365/original/file-20170817-16222-2j23u0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=718&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182365/original/file-20170817-16222-2j23u0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=718&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182365/original/file-20170817-16222-2j23u0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=718&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182365/original/file-20170817-16222-2j23u0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=902&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182365/original/file-20170817-16222-2j23u0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=902&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182365/original/file-20170817-16222-2j23u0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=902&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Voyager 2 launches aboard Titan-Centaur rocket.</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<p>When Voyager 1 arrived at Jupiter in 1979 the mission’s scientific discoveries began.</p>
<h2>Jupiter revealed close up</h2>
<p>The world watched as the Voyagers’ cameras sent back – via the tracking stations – close up images of Jupiter and its moons, letting us see these worlds in detail for the very first time. </p>
<p>From the turbulence surrounding huge storms on Jupiter, to a volcano erupting on Jupiter’s moon Io, to hints that the icy surface of Europa probably conceals an ocean underneath, the Voyager mission started to reveal the outer Solar System to us in inspiring detail.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182371/original/file-20170817-13444-1301l19.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182371/original/file-20170817-13444-1301l19.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182371/original/file-20170817-13444-1301l19.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=718&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182371/original/file-20170817-13444-1301l19.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=718&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182371/original/file-20170817-13444-1301l19.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=718&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182371/original/file-20170817-13444-1301l19.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=902&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182371/original/file-20170817-13444-1301l19.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=902&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182371/original/file-20170817-13444-1301l19.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=902&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Getting close to the Jupiter.</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182372/original/file-20170817-13501-1jy19nt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182372/original/file-20170817-13501-1jy19nt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182372/original/file-20170817-13501-1jy19nt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=502&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182372/original/file-20170817-13501-1jy19nt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=502&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182372/original/file-20170817-13501-1jy19nt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=502&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182372/original/file-20170817-13501-1jy19nt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=630&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182372/original/file-20170817-13501-1jy19nt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=630&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182372/original/file-20170817-13501-1jy19nt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=630&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Peering into Jupiter’s famous red spot.</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182373/original/file-20170817-13480-lq7fqz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182373/original/file-20170817-13480-lq7fqz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182373/original/file-20170817-13480-lq7fqz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182373/original/file-20170817-13480-lq7fqz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182373/original/file-20170817-13480-lq7fqz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182373/original/file-20170817-13480-lq7fqz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182373/original/file-20170817-13480-lq7fqz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182373/original/file-20170817-13480-lq7fqz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Voyager 1 captures a volcanic eruption on Jupiter’s moon Io.</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182366/original/file-20170817-15619-60go96.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182366/original/file-20170817-15619-60go96.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182366/original/file-20170817-15619-60go96.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=718&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182366/original/file-20170817-15619-60go96.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=718&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182366/original/file-20170817-15619-60go96.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=718&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182366/original/file-20170817-15619-60go96.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=902&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182366/original/file-20170817-15619-60go96.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=902&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182366/original/file-20170817-15619-60go96.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=902&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Voyager 1 image of Ganymede, Jupiter’s largest moon and the largest moon in the Solar System at 5,262km in diameter (compared to Earth’s Moon at 3,475km diameter).</span>
<span class="attribution"><span class="source">NASA/JPL/Image processed by Bjӧrn Jόnsson</span></span>
</figcaption>
</figure>
<p>Indeed, during the course of their 12-year mission, the Voyagers discovered 24 new moons orbiting the outer planets and refined NASA’s use of the Deep Space Network to listen to signals from distant spacecraft.</p>
<h2>To Saturn and beyond</h2>
<p>After Jupiter, both Voyagers went on to encounter Saturn. Voyager 1 achieved the major goal of closely approaching Saturn’s giant moon, Titan. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182375/original/file-20170817-13469-vt878q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182375/original/file-20170817-13469-vt878q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182375/original/file-20170817-13469-vt878q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=718&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182375/original/file-20170817-13469-vt878q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=718&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182375/original/file-20170817-13469-vt878q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=718&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182375/original/file-20170817-13469-vt878q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=902&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182375/original/file-20170817-13469-vt878q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=902&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182375/original/file-20170817-13469-vt878q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=902&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Both Voyagers passed by the ringed planet Saturn.</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<p>Following this encounter, with its primary mission ended, Voyager 1 was flung on a northward trajectory above the plain of the orbits of the planets. Voyager 2 was subsequently targeted to travel outward on an extended mission to visit the next two gas giant worlds.</p>
<p>When Voyager 2 flew past Uranus in January 1986, the signals being received were much weaker than when it flew by Saturn, five years earlier. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182382/original/file-20170817-13444-wbh9xl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182382/original/file-20170817-13444-wbh9xl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182382/original/file-20170817-13444-wbh9xl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=567&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182382/original/file-20170817-13444-wbh9xl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=567&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182382/original/file-20170817-13444-wbh9xl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=567&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182382/original/file-20170817-13444-wbh9xl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=713&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182382/original/file-20170817-13444-wbh9xl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=713&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182382/original/file-20170817-13444-wbh9xl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=713&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Voyager 2 captures Uranus.</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<p>Consequently, CSIRO’s radio telescope at Parkes was linked, or arrayed, with NASA’s dishes in Canberra to boost Voyager 2’s weak radio signal.</p>
<p>This was the first time an array of telescopes had been used to track a spacecraft. Yet this array would be insufficient to receive the even fainter signals expected when Voyager 2 reached Neptune in 1989.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182537/original/file-20170818-28120-3yf8fv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182537/original/file-20170818-28120-3yf8fv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182537/original/file-20170818-28120-3yf8fv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182537/original/file-20170818-28120-3yf8fv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182537/original/file-20170818-28120-3yf8fv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182537/original/file-20170818-28120-3yf8fv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182537/original/file-20170818-28120-3yf8fv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182537/original/file-20170818-28120-3yf8fv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">CDSCC staff at Parkes monitoring the encounter with Uranus’ moon, Miranda, in 1986.</span>
<span class="attribution"><span class="source">CSIRO</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>So in the time between the encounters, NASA expanded Canberra’s largest dish from 64 metres to 70 metres in diameter to increase its sensitivity, and then linked it again with the Parkes 64 metre dish, to maximise the data capture at Neptune. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182378/original/file-20170817-13430-t2hfq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182378/original/file-20170817-13430-t2hfq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182378/original/file-20170817-13430-t2hfq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182378/original/file-20170817-13430-t2hfq7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182378/original/file-20170817-13430-t2hfq7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182378/original/file-20170817-13430-t2hfq7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182378/original/file-20170817-13430-t2hfq7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182378/original/file-20170817-13430-t2hfq7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Neptune’s bright wispy cirrus-type clouds can been seen against the blue atmosphere.</span>
<span class="attribution"><span class="source">NASA/JPL/ Image processed by Bjӧrn Jόnsson</span></span>
</figcaption>
</figure>
<p>The increased size and sensitivity of the Canberra dish also meant that it was able to support Voyager’s ongoing journey beyond the outer planets.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182539/original/file-20170818-30283-fivs8d.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182539/original/file-20170818-30283-fivs8d.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182539/original/file-20170818-30283-fivs8d.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=461&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182539/original/file-20170818-30283-fivs8d.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=461&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182539/original/file-20170818-30283-fivs8d.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=461&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182539/original/file-20170818-30283-fivs8d.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=580&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182539/original/file-20170818-30283-fivs8d.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=580&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182539/original/file-20170818-30283-fivs8d.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=580&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Robina Otrupcek tracking Voyager 2 at Neptune from the CSIRO Parkes telescope on the day before the close approach in 1989.</span>
<span class="attribution"><span class="source">CSIRO</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>The Pale Blue Dot</h2>
<p>In 1990 Voyager 1 turned its cameras towards home. The resulting photograph, known as the Pale Blue Dot, is our most distant view of Earth, a fraction of a pixel floating in a deep black sea. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182376/original/file-20170817-13501-t0lmj2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182376/original/file-20170817-13501-t0lmj2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182376/original/file-20170817-13501-t0lmj2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=381&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182376/original/file-20170817-13501-t0lmj2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=381&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182376/original/file-20170817-13501-t0lmj2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=381&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182376/original/file-20170817-13501-t0lmj2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=479&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182376/original/file-20170817-13501-t0lmj2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=479&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182376/original/file-20170817-13501-t0lmj2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=479&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This pale blue dot, less than a pixel in size, is Voyager 1’s view of Earth.</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<p>The legendary astrophysicist Carl Sagan, involved with Voyager since its inception, reflected that this distant view of the tiny stage on which we play out our lives should inspire us “to preserve and cherish that pale blue dot, the only home we’ve ever known”.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/wupToqz1e2g?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Pale Blue Dot.</span></figcaption>
</figure>
<p>Both Voyagers have long since left the outer planets behind, two explorers heading into the galaxy in different directions, still sending data back to Earth and answering questions we didn’t even know to ask when they were launched 40 years ago.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-pale-blue-dot-and-other-selfies-of-earth-39118">The pale blue dot and other 'selfies' of Earth</a>
</strong>
</em>
</p>
<hr>
<h2>Voyagers only talk to Australia</h2>
<p>The Canberra tracking station continues to receive signals from both Voyager spacecraft every day, and is currently the only tracking station capable of exchanging signals with Voyager 2, owing to the spacecraft’s position as it heads on its southward path out of the Solar System.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182383/original/file-20170817-13501-5sxt70.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182383/original/file-20170817-13501-5sxt70.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182383/original/file-20170817-13501-5sxt70.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=411&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182383/original/file-20170817-13501-5sxt70.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=411&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182383/original/file-20170817-13501-5sxt70.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=411&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182383/original/file-20170817-13501-5sxt70.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=516&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182383/original/file-20170817-13501-5sxt70.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=516&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182383/original/file-20170817-13501-5sxt70.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=516&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Parkes telescope tracking Voyager 2 at Neptune on the day of the close approach.</span>
<span class="attribution"><span class="source">CSIRO</span></span>
</figcaption>
</figure>
<p>Due to their respective distances, tens of billions of kilometres from home, the signal strength from both spacecraft is very weak, only one-tenth of a billion-trillionth of a watt.</p>
<p>In 2012, Voyager 1 became the first spacecraft to have entered interstellar space, the region between the stars. Lying beyond the influence of the magnetic bubble generated by our Sun, Voyager 1 is able to directly study the composition of the interstellar medium, for the first time.</p>
<p>Voyager 1 is still receiving commands that can only be sent from Canberra’s dishes. It is the only station with the high-power transmitter that can transmit a signal strong enough to be received by the spacecraft.</p>
<p>It has been an epic voyage for two spacecraft no bigger than small buses, two brilliant robots with an eight track tape deck to record data and 256kB of memory.</p>
<h2>A golden message</h2>
<p>The scientists and engineers at NASA’s Jet Propulsion Laboratory in California, who built the Voyagers and continue to operate them, planned ahead for Voyager’s legacy and its journey beyond our Solar System. </p>
<p>On board both spacecraft they placed a golden record, similar in concept to a vinyl record, featuring one and a half hours of world music and greetings to the universe in 55 different languages.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182386/original/file-20170817-13469-1geh4xq.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182386/original/file-20170817-13469-1geh4xq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182386/original/file-20170817-13469-1geh4xq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=311&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182386/original/file-20170817-13469-1geh4xq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=311&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182386/original/file-20170817-13469-1geh4xq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=311&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182386/original/file-20170817-13469-1geh4xq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=391&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182386/original/file-20170817-13469-1geh4xq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=391&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182386/original/file-20170817-13469-1geh4xq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=391&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The golden record and instructions on how to play it.</span>
<span class="attribution"><span class="source">NASA/JPL</span></span>
</figcaption>
</figure>
<p>The cover art features a pictorial representation of how to play the record and a map reference to Earth’s location in our galaxy based on the positions of surrounding pulsars.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Bhuq9rNO_FQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The first of the 31 recordings. Click on the video to hear the rest.</span></figcaption>
</figure>
<p>By 2030, both Voyagers will be out of power, their scientific instruments deactivated, no longer able to exchange signals with Earth. They will continue on at their current speeds of more than 17 kilometres per second, carrying their golden records like messages in bottles across the vast ocean of interstellar space. </p>
<p>Heading in opposite directions, southward and northward out of the Solar System, it will be 40,000 years before Voyager 2 passes within a handful of light years of the closest star system along its flight path, and 296,000 years before Voyager 1 passes by the bright star Sirius.</p>
<p>Beyond that, we may imagine them surviving for billions of years as the only traces of a civilisation of human explorers in the far reaches of our galaxy.</p><img src="https://counter.theconversation.com/content/82512/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The Voyager space probes sent back some amazing images of the planets in the outer Solar System, and they’re still talking to Earth every day via Australia’s tracking station.John Sarkissian, Operations Scientist, CSIROEd Kruzins, Facilities Program Director Nasa Operations Canberra Deep Space Communication Complex , CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/798862017-08-14T02:33:24Z2017-08-14T02:33:24ZVoyager Golden Records 40 years later: Real audience was always here on Earth<figure><img src="https://images.theconversation.com/files/181457/original/file-20170808-22953-18ep7cq.jpg?ixlib=rb-1.1.0&rect=1%2C518%2C944%2C751&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What message would you send to outer space?</span> <span class="attribution"><a class="source" href="https://images.nasa.gov/#/details-PIA17035.html">NASA/JPL-Caltech</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Forty years ago, NASA launched <a href="https://www.jpl.nasa.gov/voyager/">Voyager I and II</a> to explore the outer solar system. The twin spacecraft both visited Jupiter and Saturn; from there Voyager I explored the hazy moon Titan, while Voyager II became the first (and, to date, only) probe to explore Uranus and Neptune. Since they move too quickly and have too little propellant to stop themselves, both spacecraft are now on what NASA calls their <a href="https://www.jpl.nasa.gov/voyager/mission/interstellar-mission/">Interstellar Mission</a>, exploring the space between the stars as they head out into the galaxy.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/181458/original/file-20170808-22949-142hdar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/181458/original/file-20170808-22949-142hdar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/181458/original/file-20170808-22949-142hdar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181458/original/file-20170808-22949-142hdar.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181458/original/file-20170808-22949-142hdar.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181458/original/file-20170808-22949-142hdar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181458/original/file-20170808-22949-142hdar.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181458/original/file-20170808-22949-142hdar.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Instructions to a far-off listener.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:The_Sounds_of_Earth_Record_Cover_-_GPN-2000-001978.jpg">NASA/JPL</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Both craft carry <a href="https://voyager.jpl.nasa.gov/spacecraft/goldenrec.html">Golden Records</a>: 12-inch phonographic gold-plated copper records, along with needles and cartridges, all designed to last indefinitely in interstellar space. Inscribed on the records’ covers are instructions for their use and a sort of “map” designed to describe the Earth’s location in the galaxy in a way that extraterrestrials might understand. </p>
<p>The grooves of the records record both ordinary <a href="https://www.jpl.nasa.gov/voyager/golden-record/whats-on-the-record/">audio and 115 encoded images</a>. A team led by astronomer Carl Sagan selected the contents, chosen to embody a message representative of all of humanity. They settled on elements such as audio <a href="https://www.jpl.nasa.gov/voyager/golden-record/whats-on-the-record/greetings/">greetings in 55 languages</a>, the brain waves of “a young woman in love” (actually the project’s creative director Ann Druyan, days after <a href="http://www.npr.org/2010/02/12/123534818/carl-sagan-and-ann-druyans-ultimate-mix-tape">falling in love with Carl Sagan</a>), a wide-ranging selection of <a href="https://www.jpl.nasa.gov/voyager/golden-record/whats-on-the-record/music/">musical excerpts</a> from <a href="https://en.wikipedia.org/wiki/Blind_Willie_Johnson">Blind Willie Johnson</a> to <a href="https://en.wikipedia.org/wiki/Honkyoku">honkyoku</a>, <a href="https://www.jpl.nasa.gov/voyager/golden-record/whats-on-the-record/images/">technical drawings and images of people</a> from around the world, including Saan Hunters, city traffic and a nursing mother and child. </p>
<p><audio preload="metadata" controls="controls" data-duration="8" data-image="" data-title="Greetings to you, whoever you are; we have good will toward you and bring peace across space." data-size="8424" data-source="NASA/JPL" data-source-url="https://www.jpl.nasa.gov/voyager/golden-record/whats-on-the-record/greetings/" data-license="" data-license-url="">
<source src="https://cdn.theconversation.com/audio/865/latin.mp3" type="audio/mpeg">
</audio>
<div class="audio-player-caption">
Greetings to you, whoever you are; we have good will toward you and bring peace across space.
<span class="attribution"><a class="source" rel="nofollow" href="https://www.jpl.nasa.gov/voyager/golden-record/whats-on-the-record/greetings/">NASA/JPL</a><span class="download"><span>8.23 KB</span> <a target="_blank" href="https://cdn.theconversation.com/audio/865/latin.mp3">(download)</a></span></span>
</div></p>
<p>Since we still have not detected any alien life, we cannot know to what degree the records would be properly interpreted. Researchers still debate what <a href="https://www.jstor.org/stable/1576671?seq=1%23page_scan_tab_contents">forms such messages should take</a>. For instance, should they include a star map identifying Earth? Should we focus on ourselves, or all life on Earth? Should we present ourselves as we are, or as comics artist Jack Kirby would have had it, as “the <a href="http://dailygrail.com/Alien-Nation/2016/6/Comics-Legend-Jack-Kirby-Worried-Our-Attempts-Contact-Aliens-Might-Attract-Tiger">exuberant, self-confident super visions</a> with which we’ve clothed ourselves since time immemorial”?</p>
<p>But the records serve a broader purpose than spreading the word that we’re here on our blue marble. After all, given the vast distances between the stars, it’s not realistic to expect an answer to these messages within many human lifetimes. So why send them and does their content even matter? Referring to earlier, similar efforts with the <a href="https://www.nasa.gov/centers/ames/missions/archive/pioneer.html">Pioneer spacecraft</a>, Carl Sagan <a href="https://doi.org/10.1126/science.175.4024.881">wrote</a>, “the greater significance of <a href="https://solarsystem.nasa.gov/galleries/pioneer-plaque">the Pioneer 10 plaque</a> is not as a message to out there; it is as a message to back here.” The real audience of these kinds of messages is not ET, but humanity.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/181462/original/file-20170808-16059-1v78wwt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/181462/original/file-20170808-16059-1v78wwt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/181462/original/file-20170808-16059-1v78wwt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181462/original/file-20170808-16059-1v78wwt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181462/original/file-20170808-16059-1v78wwt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181462/original/file-20170808-16059-1v78wwt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181462/original/file-20170808-16059-1v78wwt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181462/original/file-20170808-16059-1v78wwt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Pioneer 10’s plaque: ‘Hi, we’re here.’</span>
<span class="attribution"><a class="source" href="https://images.nasa.gov/#/details-ARC-1972-AC72-1338.html">NASA</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>In this light, 40 years’ hindsight shows the experiment to be quite a success, as they continue to inspire research and reflection.</p>
<p>Only two years after the launch of these messages to the stars, “Star Trek: The Motion Picture” imagined the success of similar efforts by (the fictional) Voyager VI. Since then, there have been <a href="https://is.cuni.cz/webapps/zzp/detail/64647/?lang=en">Ph.D. theses written on the records’ content</a>, <a href="https://www.theatlantic.com/technology/archive/2017/06/solving-the-mystery-of-whose-laughter-is-on-the-golden-record/532197/">investigations into the identity of the person heard laughing</a> and successful <a href="https://www.kickstarter.com/projects/ozmarecords/voyager-golden-record-40th-anniversary-edition">crowdfunded efforts</a> to <a href="http://www.ozmarecords.com/voyager">reissue the records</a> themselves for home playback.</p>
<p>The choice to include music has inspired <a href="http://dx.doi.org/10.1080/00909889309365379">introspection</a> on the nature of music as a human endeavor, and what it would (or even could) mean to an alien species. If an ET even has ears, it’s still far from clear whether it would or could appreciate rhythm, tones, vocal inflection, verbal language or even art of any kind. As music scholars <a href="http://www.tandfonline.com/doi/abs/10.1080/00909889309365379">Nelson and Polansky put it</a>, “By imagining an Other listening, we reflect back upon ourselves, and open our selves and cultures to new musics and understandings, other possibilities, different worlds.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/181464/original/file-20170808-16068-1wxrpc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/181464/original/file-20170808-16068-1wxrpc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/181464/original/file-20170808-16068-1wxrpc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=477&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181464/original/file-20170808-16068-1wxrpc8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=477&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181464/original/file-20170808-16068-1wxrpc8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=477&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181464/original/file-20170808-16068-1wxrpc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=599&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181464/original/file-20170808-16068-1wxrpc8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=599&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181464/original/file-20170808-16068-1wxrpc8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=599&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Engineers mount the Golden Record and secure its cover on Voyager 1.</span>
<span class="attribution"><a class="source" href="https://images.nasa.gov/#/details-PIA21740.html">NASA/JPL-Caltech</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The records also represent humanity’s deliberate effort to put artifacts among the stars. Unlike everything on Earth, which is subject to erosion and all but inevitable destruction (from the sun’s eventual demise, if nothing else), the Golden Records are essentially eternal, a permanent time capsule of humanity. And unlike the Voyager spacecraft themselves – which were designed to have finite lifespans and whose journey into interstellar space was incidental to their primary function of exploring the outer planets – the Golden Records’ only purpose is to serve as ambassadors of humanity to the stars.</p>
<p>Placing artifacts in interstellar space thus makes the galaxy subject to the social studies, in addition to astronomy. The Golden Records mark our claim to interstellar space as part of our <a href="https://doi.org/10.1007/978-3-319-07866-3_1">cultural landscape and heritage</a>, and once the Voyager spacecraft themselves are not functional any longer, they will <a href="https://doi.org/10.1007/978-3-319-07866-3_4">become proper achaeological objects</a>. They are, in a sense, how we as a species have planted our flag of exploration in space. Anthropologist Michael Oman-Reagan <a href="https://doi.org/10.17605/OSF.IO/R4GHB">muses</a>, “Has NASA been to interstellar space because this spacecraft has? Have we, as a human species, [now] been to interstellar space?”</p>
<p>I would argue we have, and we are a better species for it. Like the Pioneer plaques and the <a href="https://en.wikipedia.org/wiki/Arecibo_message">Arecibo Message</a> before them, the Golden Records inspire us to broaden our minds about what it means to be human; what we value as humans; and about our place and role in the cosmos by having us imagine what we might, or might not, have in common with any alien species our Voyagers eventually encounter on their very long journeys.</p><img src="https://counter.theconversation.com/content/79886/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jason Wright acknowledges funding from NASA, the NSF, the Center for Exoplanets and Habitable Words at The Pennsylvania State University, and from Breakthrough Listen, part of the Breakthrough Initiatives sponsored by the Breakthrough Prize Foundation (<a href="https://breakthroughinitiatives.org/">https://breakthroughinitiatives.org/</a>).</span></em></p>Humanity is the real target for these recordings which continue to inspire us to better understand ourselves and our place in the cosmos.Jason Wright, Professor of Astronomy and Astrophysics, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/448092015-07-21T10:18:51Z2015-07-21T10:18:51ZNew Horizons brought our last ‘first look’ at one of the original nine solar system planets<figure><img src="https://images.theconversation.com/files/89049/original/image-20150720-12527-w1dc8s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">We got you, Pluto!</span> <span class="attribution"><a class="source" href="http://pluto.jhuapl.edu/Multimedia/Images/Artist-Renderings.php">JHUAPL/SwRI</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Carl Sagan <a href="http://www.cambridge.org/us/academic/subjects/astronomy/astronomy-general/carl-sagans-cosmic-connection-extraterrestrial-perspective">famously said</a> we were the luckiest generation, to be present during the first reconnaissance of the solar system. The New Horizons mission to Pluto completes this half-century project with its stunning images and data. Meanwhile, however, space science has helped change dramatically our notions of solar systems and planets, with Pluto’s status itself the subject of controversy while New Horizons was on its way.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/88856/original/image-20150717-21052-17flsu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/88856/original/image-20150717-21052-17flsu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/88856/original/image-20150717-21052-17flsu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=507&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88856/original/image-20150717-21052-17flsu8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=507&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88856/original/image-20150717-21052-17flsu8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=507&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88856/original/image-20150717-21052-17flsu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=637&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88856/original/image-20150717-21052-17flsu8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=637&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88856/original/image-20150717-21052-17flsu8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=637&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">First image of the far side of the moon, courtesy of the USSR’s Luna 3 spacecraft.</span>
</figcaption>
</figure>
<p>I saw the first Soviet image of the far side of the moon in a grainy newspaper reproduction in 1959, and watched a <a href="http://www.jpl.nasa.gov/missions/ranger-7/">Ranger probe</a> hit the moon in 1964, from a black-and-white 10-inch television, picture by picture.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/89019/original/image-20150720-12543-1m62g2q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/89019/original/image-20150720-12543-1m62g2q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/89019/original/image-20150720-12543-1m62g2q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=636&fit=crop&dpr=1 600w, https://images.theconversation.com/files/89019/original/image-20150720-12543-1m62g2q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=636&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/89019/original/image-20150720-12543-1m62g2q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=636&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/89019/original/image-20150720-12543-1m62g2q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=800&fit=crop&dpr=1 754w, https://images.theconversation.com/files/89019/original/image-20150720-12543-1m62g2q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=800&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/89019/original/image-20150720-12543-1m62g2q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=800&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Saturn as seen by Voyager 2 upon approach.</span>
<span class="attribution"><a class="source" href="http://photojournal.jpl.nasa.gov/catalog/PIA03152">NASA/JPL</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>I followed the exploration of the inner solar system, and while in graduate school was an intern at NASA headquarters in 1981 when <a href="http://www.nasa.gov/mission_pages/voyager/overview">Voyager 2</a> encountered Saturn (the video projector failed, and a technician brought in a small, color set for an auditorium full of people).</p>
<p>By then, Pluto had long been axed from the Grand Tour that would have visited all the outer planets. While scientists, no less than the public, reveled in the episodic reports from the two Voyagers and others, the <a href="http://www.nytimes.com/2015/07/19/us/the-long-strange-trip-to-pluto-and-how-nasa-nearly-missed-it.html">friends of Pluto regrouped</a>. In the early 1980s, a wood model of a proposed Pluto explorer spacecraft adorned a hallway at NASA headquarters, its large radio dish oriented up like a giant bowl. A sign of those fiscal times, people started throwing spare change into the dish antenna.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/88863/original/image-20150717-21073-djnx81.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/88863/original/image-20150717-21073-djnx81.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/88863/original/image-20150717-21073-djnx81.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=312&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88863/original/image-20150717-21073-djnx81.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=312&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88863/original/image-20150717-21073-djnx81.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=312&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88863/original/image-20150717-21073-djnx81.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=392&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88863/original/image-20150717-21073-djnx81.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=392&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88863/original/image-20150717-21073-djnx81.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=392&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">1994 Hubble Space Telescope image of Pluto and its moon, Charon.</span>
<span class="attribution"><a class="source" href="http://hubblesite.org/newscenter/archive/releases/1994/17/image/a/">Dr R Albrecht, ESA/ESO Space Telescope European Coordinating Facility; NASA</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>But, about that time, exciting astronomical observations and theory began to reveal the Pluto neighborhood. First, a companion moon, then more, and also discoveries of individual bodies in that remote part of our solar system. As it got more crowded, the almost underground murmurs among astronomers that had for decades suggested Pluto was not in fact the missing “Planet X” believed to have been found in 1930 grew louder.</p>
<p>At one astronomical meeting, I sat near Clyde Tombaugh, discoverer of Pluto, when its planetary status was challenged. Tombaugh, then in his 90’s, jumped to his feet to defend his charge with characteristic vigor. Ironically, it was in part that challenge to planetary status and the intellectual redefinition of the solar system within which it was embedded that may have shaken loose enough spare change to mount a Pluto mission. Incidentally, a small portion of Tombaugh’s cremains are on the New Horizons spacecraft.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/88877/original/image-20150717-21027-1rk5d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/88877/original/image-20150717-21027-1rk5d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/88877/original/image-20150717-21027-1rk5d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88877/original/image-20150717-21027-1rk5d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88877/original/image-20150717-21027-1rk5d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88877/original/image-20150717-21027-1rk5d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88877/original/image-20150717-21027-1rk5d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88877/original/image-20150717-21027-1rk5d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Celebrating the success of the Apollo 11 lunar landing mission in the Mission Control Center.</span>
<span class="attribution"><a class="source" href="http://www.nasa.gov/multimedia/imagegallery/image_feature_1718.html">NASA</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The boomers are the first generation to witness the <a href="http://www.nasa.gov/pdf/607087main_NASAsFirst50YearsHistoricalPerspectives-ebook.pdf#page=443">initial exploration of our solar system</a> and the last to be taught that standard phrase, “the nine planets.” During the last half-century, scientific research and Cold War politics brought to a head changes in scientific disciplines and organization that had been maturing for centuries.</p>
<p>Astronomers had done their work from afar using large telescopes, and geologists had done theirs up close with other tools. Astronomers saw the big picture and struggled to tease out the details. Geologists and other “earth scientists” crawled over the details and struggled to see the big picture. High-tech science and planetary voyages mixed up these tidy disciplinary lines, as much as they challenged the schemes that had organized our world too simplistically into galaxies, stars, planets and moons.</p>
<p>Cold War politics loosened funds and stimulated astronomy, which needed to get beyond our blurry and filtered atmosphere, and planetary science, which needed to get spacecraft and instruments directly to the planets. While astronomy enjoyed a true revolution in understanding the remote and energetic bodies of the universe, geosciences moved beyond just the earth and morphed into a truly comparative planetary science.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/89028/original/image-20150720-12536-z9rr2l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/89028/original/image-20150720-12536-z9rr2l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/89028/original/image-20150720-12536-z9rr2l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=502&fit=crop&dpr=1 600w, https://images.theconversation.com/files/89028/original/image-20150720-12536-z9rr2l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=502&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/89028/original/image-20150720-12536-z9rr2l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=502&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/89028/original/image-20150720-12536-z9rr2l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=631&fit=crop&dpr=1 754w, https://images.theconversation.com/files/89028/original/image-20150720-12536-z9rr2l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=631&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/89028/original/image-20150720-12536-z9rr2l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=631&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">We’ve come a long way from Earth at the center of it all.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Cellarius_ptolemaic_system_c2.jpg">Johannes van Loon</a></span>
</figcaption>
</figure>
<p>Reporting his first telescopic observations in 1610, Galileo remarked that watching sunrise over the mountains of the moon from Venice must look much the same as watching sunrise over the mountains of Bohemia from the moon. The issue of Copernicanism at the time is often phrased as whether the Earth or the sun is the center.</p>
<p>The sleeper issue that would take another four centuries to mature, however, was really about worlds and planets. Galileo and his immediate successors realized that all the planets were worlds in themselves, kin to our previously unique world, and could all be studied in similar ways. While telescopes did get better and better over the next four centuries, only the very largest planets and moons could be observed.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/88876/original/image-20150717-21047-1df8np6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/88876/original/image-20150717-21047-1df8np6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/88876/original/image-20150717-21047-1df8np6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=377&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88876/original/image-20150717-21047-1df8np6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=377&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88876/original/image-20150717-21047-1df8np6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=377&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88876/original/image-20150717-21047-1df8np6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=473&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88876/original/image-20150717-21047-1df8np6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=473&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88876/original/image-20150717-21047-1df8np6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=473&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The solar system as we’ve traditionally thought about it.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Solar_sys.jpg">NASA</a></span>
</figcaption>
</figure>
<p>Our simplistic diagram of nine planets in largely empty space circling a sun has yielded to a hugely complex and subtle collection of bodies of every size, interacting with one another, sometimes traveling widely, and kin to the one we call home. This is the completion of the Copernican revolution. It extends from gigantic and exotic worlds like Jupiter to the molecules and chemistry of the life that gives rise to our curiosity. To <a href="http://www.penguinrandomhouse.com/books/159730/cosmos-by-carl-sagan/">paraphrase Sagan</a> again, we are a part of the universe that has evolved to contemplate and study the rest.</p>
<figure>
<img src="http://www.nasa.gov/sites/default/files/thumbnails/image/pluto-observations-through-the-years.gif">
<figcaption><span class="caption">Animation of Pluto observations from 1930 to 2015.</span> <span class="source">Lowell Observatory and NASA</span></figcaption>
</figure>
<p>The entire New Horizons mission over 15 years cost about <a href="http://solarsystem.nasa.gov/missions/profile.cfm?MCode=PKB&Display=ReadMore">US$700 million</a>, or $47 million per year – less than Americans <a href="http://www.bea.gov/iTable/iTable.cfm?ReqID=21&step=2#reqid=21&step=9&isuri=1&2103=70">spend on soft drinks</a>. All of space exploration is but spare change, and this mission’s tariff almost invisible on <a href="http://www.lpi.usra.edu/exploration/multimedia/NASABudgetHistory.pdf">anybody’s ledger</a>.</p>
<p>Like the Romans, we demanded bread and circuses during the space program’s heyday in its first decade or so. This circus is already quite a bargain. Throw some spare change into the next model of an orphan mission of exploration. You will need to have patience, but you will be rewarded.</p><img src="https://counter.theconversation.com/content/44809/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Joseph N Tatarewicz has received funding from the NASA History Office and from the Smithsonian Institution for work on which some of this contribution is based.</span></em></p>In the long lead-up to our ultimate flyby of Pluto, space science has reconfigured our notions of what it means to be a solar system, a planet, a world.Joseph Tatarewicz, Associate Professor of History, University of Maryland, Baltimore CountyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/391182015-04-05T22:49:12Z2015-04-05T22:49:12ZThe pale blue dot and other ‘selfies’ of Earth<figure><img src="https://images.theconversation.com/files/75632/original/image-20150323-26729-1ocuw8j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pale Blue Dot -- Earth, imaged by Voyager 1 from 6 billion kilometres away.</span> <span class="attribution"><a class="source" href="https://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=2148">NASA.</a></span></figcaption></figure><p>Twenty-five years ago a set of images were taken that provided a unique view of Earth and helped highlight the fragility of our existence, and the importance of our stewardship.</p>
<p>As the <a href="https://theconversation.com/au/topics/voyager">Voyager 1</a> planetary spacecraft went beyond the orbit of Pluto on February 14, 1990, it took one last look at Earth. Three exposures, each one in a different filter, contained a very small and faint Earth.</p>
<p>The images were then stored on-board, on a tape recorder but because of competing planetary missions the data took until May 1990 to arrive back on Earth.</p>
<p>Despite Voyager 1 being more than 6 billion kilometres from Earth, the three exposures ranged only between 0.48 and 0.72 seconds in duration. But the data took five and a half hours, travelling at the speed of light, to span the distance between the spacecraft and Earth.</p>
<h2>A ‘selfie’ of Earth</h2>
<p>Three images (separately in blue, green and violet light) were combined to produce the now famous Pale Blue Dot image, Voyager 1’s “selfie” of Earth.</p>
<p>It is an image that contains all of Earth and yet <a href="http://visibleearth.nasa.gov/view.php?id=52392">NASA says</a> Earth was a crescent at the time and only 0.12 of one pixel in size.</p>
<p>Earth has a blue appearance due to reflected light scattering off oceans, clouds and land. The faint band of light in which it is seemingly suspended is not some celestial filament but an artifact of scattered sunlight.</p>
<p>Pale Blue Dot was part of a remarkable larger “<a href="http://www.planetary.org/multimedia/space-images/charts/solar-system-family-portrait.html">family</a>” portrait of the solar system, an idea the famous American astronomer Carl Sagan, a member of the Voyager imaging team, came up with many years before 1990.</p>
<p>Despite our planet being so small, the image has a strangely magical quality in which for the first time we can begin to appreciate our place, not only in the much larger solar system, but in the galaxy we reside, that is part of our universe.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/75596/original/image-20150323-14630-1t8g4so.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/75596/original/image-20150323-14630-1t8g4so.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/75596/original/image-20150323-14630-1t8g4so.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=475&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75596/original/image-20150323-14630-1t8g4so.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=475&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75596/original/image-20150323-14630-1t8g4so.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=475&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75596/original/image-20150323-14630-1t8g4so.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=596&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75596/original/image-20150323-14630-1t8g4so.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=596&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75596/original/image-20150323-14630-1t8g4so.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=596&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">These six narrow-angle colour images were made from the first ever.
‘portrait’ of the solar system taken by Voyager 1.</span>
<span class="attribution"><a class="source" href="http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-solarsystem.html">NASA, Voyager 1</a></span>
</figcaption>
</figure>
<p>Our Earth dot is not distinguishable from the other dots in the larger solar system portrait. </p>
<p>Yet, it is of course special. For one thing, in 1977 we launched a spacecraft called Voyager 1 from that dot.</p>
<p>Sagan titled his 1994 book <a href="https://www.goodreads.com/book/show/61663.Pale_Blue_Dot">Pale Blue Dot: A Vision of the Human Future in Space</a> after the image, and in it he said:</p>
<blockquote>
<p>Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light.</p>
</blockquote>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/wupToqz1e2g?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>Other ‘selfies’ of Earth</h2>
<p>The Pale Blue Dot was not the first image of Earth taken from space. On Christmas Eve 1968, Apollo 8 astronauts William Anders, James Lovell and Frank Borman were in lunar orbit and took several images of an Earth rising above the moon’s horizon.</p>
<p>One image in particular – known as Earthrise – has resonated like the Pale Blue Dot.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/75607/original/image-20150323-14609-1x0mv4q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/75607/original/image-20150323-14609-1x0mv4q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/75607/original/image-20150323-14609-1x0mv4q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75607/original/image-20150323-14609-1x0mv4q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75607/original/image-20150323-14609-1x0mv4q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75607/original/image-20150323-14609-1x0mv4q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75607/original/image-20150323-14609-1x0mv4q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75607/original/image-20150323-14609-1x0mv4q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Earthrise.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/multimedia/imagegallery/image_feature_1249.html#.VQ9lO_l9J2A">NASA</a></span>
</figcaption>
</figure>
<p>The image of a hemispherically illuminated blue sea, white cloud (with traces of brown land) Earth seemingly floating above the lunar horizon as the astronauts orbited the moon, is iconic.</p>
<p>The Earth was too small to easily identify known features. Craters and other features of the moon’s surface clearly show that the photographers had left their home.</p>
<p>You can watch a recreation of the time in the mission when the images were taken in this video (below).</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/dE-vOscpiNc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Apollo astronauts, the first to journey to the moon, were also the first humans to take images of the whole Earth. At such distances, at least in the daylight part, cities and evidence of humans are invisible.</p>
<p>Apollo 8 command module pilot Jim Lovell, picturing himself as a first-time Earth visitor, <a href="http://www.hq.nasa.gov/pao/History/SP-4205/ch11-6.html">commented</a> to his mission commander Frank Borman:</p>
<blockquote>
<p>Frank, what I keep imagining is if I am some lonely traveller from another planet what I would think about the Earth at this altitude, whether I think it would be inhabited or not […] I was just curious if I would land on the blue or brown part of the Earth.</p>
</blockquote>
<p>In December 1972, only four years after Apollo 8, the Apollo 17 crew took one of the most famous and widely used whole-Earth images from a distance of 45,000km on its outbound leg, dubbed the “The Blue Marble” for obvious reasons.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/75612/original/image-20150323-14609-13syqje.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/75612/original/image-20150323-14609-13syqje.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/75612/original/image-20150323-14609-13syqje.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75612/original/image-20150323-14609-13syqje.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75612/original/image-20150323-14609-13syqje.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75612/original/image-20150323-14609-13syqje.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75612/original/image-20150323-14609-13syqje.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75612/original/image-20150323-14609-13syqje.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Blue Marble.</span>
<span class="attribution"><a class="source" href="http://earthobservatory.nasa.gov/IOTD/view.php?id=1133">NASA</a></span>
</figcaption>
</figure>
<p>Similar whole-Earth images had been taken as early as 1967 by satellites but the Blue Marble combines human photographer, a unique alignment of sun, spacecraft and Earth and the most artistic (even abstract!) mix of land, ocean and cloud.
This combination has elevated this image above many similar ones. It is an Earth we know. </p>
<h2>The human ‘selfie’ in space</h2>
<p>The first human selfie in space – which also includes Earth – was seemingly taken by Edwin “Buzz” Aldrin in 1966 during the Gemini 12 mission. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/75626/original/image-20150323-26733-1yogiqf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/75626/original/image-20150323-26733-1yogiqf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/75626/original/image-20150323-26733-1yogiqf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=540&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75626/original/image-20150323-26733-1yogiqf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=540&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75626/original/image-20150323-26733-1yogiqf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=540&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75626/original/image-20150323-26733-1yogiqf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=679&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75626/original/image-20150323-26733-1yogiqf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=679&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75626/original/image-20150323-26733-1yogiqf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=679&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Edwin ‘Buzz’ Aldrin during the Gemini 12 mission in 1966.</span>
<span class="attribution"><a class="source" href="http://spaceflight.nasa.gov/gallery/images/gemini/gemini12/html/s66-62926.html">NASA</a></span>
</figcaption>
</figure>
<p>Note that this was taken while in a bulky spacesuit, wearing thick gloves, pre-smartphone and many years before the common use of the <a href="http://en.wikipedia.org/wiki/Selfie_stick">selfie-stick</a>.</p>
<p>Selfies of International Space Station (ISS) residents and even ISS spacewalkers appear regularly in social media and these images now seem to be somewhat expected and slightly mundane.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"577169264114728960"}"></div></p>
<p>Not to be outdone, machines have joined the quest for self reflection. As far back as 1976 the Viking 2 lander on Mars took partial self-portraits, containing part of the lander with the Martian horizon in the background.</p>
<p>In 2013, also on Mars, NASA’s Curiosity rover took 66 high-resolution images, which together made this wonderful self-portrait. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/75628/original/image-20150323-26733-8jh8jr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/75628/original/image-20150323-26733-8jh8jr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/75628/original/image-20150323-26733-8jh8jr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=462&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75628/original/image-20150323-26733-8jh8jr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=462&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75628/original/image-20150323-26733-8jh8jr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=462&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75628/original/image-20150323-26733-8jh8jr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=581&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75628/original/image-20150323-26733-8jh8jr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=581&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75628/original/image-20150323-26733-8jh8jr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=581&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A self-portrait of NASA’s Mars rover Curiosity.</span>
<span class="attribution"><a class="source" href="http://photojournal.jpl.nasa.gov/catalog/PIA16763">NASA/JPL-Caltech/MSSS</a></span>
</figcaption>
</figure>
<p>But selfies of robots do not strongly resonate with me. What strikes me the most are images of Earth taken by us or our machines. Whether it is from high orbit, en route to the moon, from another part of the solar system or even from outside the solar system, our ability to take images of our planet has changed our perspective forever. It is us we are looking back upon. </p>
<p>Most of the Apollo astronauts commented that their original mission objective was the moon, yet their biggest impact came from viewing the (their) Earth. </p>
<p>Some 40 years after his mission to the moon, Apollo 8’s William (Bill) Anders told a television documentary that:</p>
<blockquote>
<p>It’s tiny out there […] it’s inconsequential. It’s ironic that we had come to study the moon and it was really discovering the Earth.</p>
</blockquote>
<p>In the near future the images taken during Apollo will be joined by images of Earth taken from human travellers to, and residents of Mars.</p>
<p>In the short term though the Pale Blue Dot will not be matched in the impact and reaction it creates.</p>
<p>In that one dot is our 5 billion year old planet with its unique mix of favourable position from the sun, liquid water, tectonic activity, thin atmosphere, life and unique flora and fauna.</p>
<p>It represents all human history, our discoveries, our evolved intellect, our social achievements, our destructive wars, our families and loved ones, all those before us and the current seven billion humans and rising, in lockstep with increasing environmental and resources impact.</p>
<h2>Beyond the Pale Blue Dot</h2>
<p>Voyager 1 is now more than 19 billion kilometres from Earth. It has travelled 13 billion kilometres in the 25 years since since taking the original Pale Blue Dot. Even if the camera that took the image could be brought back to life, it is unlikely a similar set of images would detect Earth. </p>
<p>From the more distant Voyager 1 perspective Earth is both fainter by a factor of ten and closer to a still bright sun.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/L4hf8HyP0LI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Voyager 1 is now regarded as being in <a href="https://theconversation.com/voyager-1-is-leaving-the-solar-system-but-the-journey-continues-11184">interstellar space</a>, as it is outside the influence of our sun and is travelling toward the constellation Ophiuchus. In the year 40,272 AD, Voyager 1’s <a href="http://www.space.com/22783-voyager-1-interstellar-space-star-flyby.html">next encounter</a> will be to come within 1.7 light years of a star in the constellation Ursa Minor called AC+79 3888.</p>
<p>What will Earth look like in 40,272 AD? More importantly, what will Earth look like in 4027 AD, only slightly more than 2,000 years from now? Will future spacecraft over the next 2,000 years take as potent images as Pale Blue Dot, Earthrise or the Blue Marble? </p>
<p>Apollo showed a recognisable but seemingly fragile home planet. Voyager 1 showed an unremarkable dot much like several others in our star’s planetary system. Has the evolving Earth “selfie” changed our behaviour?</p>
<p>Human selfies are often perceived as having a negative narcissistic component. The Earth “selfie” has only positive attributes.</p>
<p>A century ago, the famous naturalist John Muir seemed to anticipate the Earth “selfie” when he wrote in his book <a href="https://www.goodreads.com/book/show/453231.Travels_in_Alaska">Travels in Alaska</a>:</p>
<blockquote>
<p>[…] when we contemplate the whole globe as one great dewdrop, striped and dotted with continents and islands, flying through space with other stars all singing and shining together as one, the whole universe appears as an infinite storm of beauty.</p>
</blockquote>
<p>Such self-portraits of Earth should make us continually ask are we worthy stewards to help navigate our home through John Muir’s stormy yet beautiful universe?</p><img src="https://counter.theconversation.com/content/39118/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Glen Mackie does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>From a big blue marble to a tiny dot in space – reflections on our images of Earth.Glen Mackie, Senior Lecturer in Astronomy & Astrophysics, Coordinator of Swinburne Astronomy Online, Swinburne University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/182882013-10-03T02:22:12Z2013-10-03T02:22:12ZBeyond the morning star: the real tale of the Voyagers’ Aboriginal music<figure><img src="https://images.theconversation.com/files/32300/original/6cyk8jw2-1380690238.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Two golden records, on their way out of our solar system, carry Australian Aboriginal music – but what's the real story behind the recording?</span> <span class="attribution"><span class="source">x-ray delta one</span></span></figcaption></figure><p>Earlier this year, NASA spacecraft Voyager 1 <a href="http://www.sciencemag.org/content/341/6153/1489.abstract">left our solar system</a> after a 35-year journey, carrying with it a golden record containing sounds, images and music from Earth.</p>
<p>Its sister craft, <a href="http://www.nasa.gov/mission_pages/voyager/voyager20130912.html">Voyager 2</a>, carries an identical record. The records were designed to encapsulate the aural heritage of Earth in 90 minutes - but some preliminary investigation, however, reveals that there a few inaccuracies in the <a href="http://voyager.jpl.nasa.gov/spacecraft/music.html">official NASA documentation</a> about the golden records.</p>
<p>When senior Aboriginal men Djawa, Mudpo and Waliparu gathered one night in 1962 on Milingimbi mission in Arnhem Land for a recording session with Australian anthropologist <a href="http://www.austlit.edu.au/austlit/page/A145812">Sandra Le Brun Holmes</a>, they little dreamt that their music would be heading to the stars on the famous spacecraft. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/32306/original/f93yv793-1380690839.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/32306/original/f93yv793-1380690839.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/32306/original/f93yv793-1380690839.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=820&fit=crop&dpr=1 600w, https://images.theconversation.com/files/32306/original/f93yv793-1380690839.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=820&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/32306/original/f93yv793-1380690839.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=820&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/32306/original/f93yv793-1380690839.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1030&fit=crop&dpr=1 754w, https://images.theconversation.com/files/32306/original/f93yv793-1380690839.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1030&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/32306/original/f93yv793-1380690839.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1030&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Carl Sagan.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>More than a decade later, American astronomer <a href="http://www.carlsagan.com/">Carl Sagan</a> put together a committee to discuss a “time capsule” for NASA’s Voyager interstellar mission, to be launched in 1977. </p>
<p>Astronomer <a href="http://www.seti.org/drake">Frank Drake</a> suggested a record rather than a plaque, as was used on the earlier <a href="http://www.nasa.gov/centers/ames/missions/archive/pioneer.html%E2%80%8E">Pioneer 10 and 11</a>, and suddenly, music was on the table.</p>
<p>The process of selecting this “world music” is described in Sagan’s book <a href="http://www.goodreads.com/book/show/263952.Murmurs_of_Earth">Murmurs of Earth</a>. Many factors determined the final cut: the quality of the recording, cultural diversity, geographic and chronological range. </p>
<p>The ultimate hope was that the records could not only represent human culture, but also human cultural evolution.</p>
<h2>The Land of the Morning Star</h2>
<p>In 1962, Le Brun Holmes and her husband, filmmaker <a href="http://en.wikipedia.org/wiki/Cecil_Holmes_(director%29)">Cecil Holmes</a>, toured Methodist missions in the Top End to make the film Faces in the Sun. At Milingimbi, she recalls in her autobiography, people would come to visit her after the day’s work was over:</p>
<blockquote>
<p>During such evenings […] I recorded a number of beautiful songs, didjeridu solos and stories from the men. One man named Mudpo was a virtuoso on the didjeridu, able to make the sounds of birds at the same time as the wonderful resonant music rolled on uninterrupted. There were fast songs and slow, ghostly music about <em>morkois</em> (ghosts). These men were masters of the instrument. It was the best music I had ever heard, in the true classical, ceremonial tradition.</p>
</blockquote>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/32309/original/53k62s8m-1380691693.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/32309/original/53k62s8m-1380691693.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/32309/original/53k62s8m-1380691693.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=361&fit=crop&dpr=1 600w, https://images.theconversation.com/files/32309/original/53k62s8m-1380691693.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=361&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/32309/original/53k62s8m-1380691693.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=361&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/32309/original/53k62s8m-1380691693.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=454&fit=crop&dpr=1 754w, https://images.theconversation.com/files/32309/original/53k62s8m-1380691693.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=454&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/32309/original/53k62s8m-1380691693.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=454&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Who were these master musicians and custodians of their culture? </p>
<p>Djawa is well known: he was a community leader and artist, and a winner of the 1955 Leroy-Alcorso Textile Design Competition. Numerous of his bark paintings are in the <a href="http://www.nma.gov.au/collections-search/results?QueryTerms=djawa&search=basic">National Museum of Australia</a>. </p>
<p>But his voice did not make it onto the golden record; we only hear him playing clapsticks under Mudpo’s didjeridu in “Morning Star”. Mudpo, and Waliparu who sings the haunting “Moikoi”, are absent from the easily accessible archives. </p>
<p>There is little trace of them apart from the sleeve notes of the record Le Brun Holmes later released as <a href="http://www.manikay.com/albums/landmorningstar.shtml">Land of the Morning Star</a>. To find out more, we would have to dive deeper into mission records and talk to their families and people who knew them.</p>
<h2>The music that really went into space</h2>
<p>According to Murmurs of Earth, the songs were recorded in 1958, and 1m 26s on the golden records included “Morning Star” and “Devil Bird”. </p>
<p>However, Le Brun Holmes’ first visit to Milingimbi occurred in 1962. And when the golden record is compared with the original recording, it becomes clear that the didjeridu and clapsticks (Mudpo and Djawa) is the first 23s, with Djawa’s vocal cut off, while the remainder is not the “Devil Bird” song at all, but Waliparu singing “Moikoi”.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/lapeaVqH43g?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Video caption here.</span></figcaption>
</figure>
<p>“Morning Star” is a clan song (<em>manikay</em>) relating to the <em>Barnumbirr</em> morning star ceremonies; such songs were not unlike title deeds, expressing the relationship of families or clans to areas of land through the ancestral spirits. The ceremonies are about the journey of the souls of the dead to land of the morning star. </p>
<p>“Moikoi” is about the <em>morkoi</em>, malicious spirits who try to entice newly deceased souls away from their clan country. The songs, in their new context on the spacecraft, could perhaps be read as a message about the journey of the human spirit between Earth and space – and home at last.</p>
<h2>Frozen in time or a living future?</h2>
<p>This is how Sagan summed up the purpose of the golden records in 1978, the year following their launch:</p>
<blockquote>
<p>Our concern with time and our sense of the Voyager message as a time capsule is expressed in many places on the record - greetings in Sumerian, Hittite and !Kung, photographs of Kalahari Bushmen, music from New Guinea and from the Australian Aborigines, and the inclusion of the composition “Flowing Streams”, whose original structure antedates Pythagoras and perhaps goes back to the time of Homer.</p>
</blockquote>
<p>Interestingly, the Indigenous groups mentioned here are among those most often singled out in early anthropology and popular conceptions as the most “primitive” on Earth. They are mentioned in the same breath with long-dead cultures known mainly from archaeology.</p>
<p>But these were not dead and dying cultures. Throughout the 1950s, ‘60s and '70s, <a href="http://en.wikipedia.org/wiki/Yolngu_people">Yolngu</a> people in Arnhem Land were fighting battles to maintain their land and culture against the onslaught of missionisation, mining, and exploitative art dealers. </p>
<p>In 1962, when the recording was made, Aboriginal people were subjected to the pernicious assimilation policy which supported the stolen generations and denied them just wages for their labour. </p>
<p>In the 1970s, the decade of the Voyager missions, assimilation was superseded by self-determination; yet the rights of Yolngu people were easily discarded when mining interests were at stake. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/32361/original/s3vrt7ym-1380764929.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/32361/original/s3vrt7ym-1380764929.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/32361/original/s3vrt7ym-1380764929.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/32361/original/s3vrt7ym-1380764929.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/32361/original/s3vrt7ym-1380764929.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/32361/original/s3vrt7ym-1380764929.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/32361/original/s3vrt7ym-1380764929.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/32361/original/s3vrt7ym-1380764929.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The painting second from the left is of the Morning Star ceremony.</span>
<span class="attribution"><span class="source">Art Gallery of New South Wales</span></span>
</figcaption>
</figure>
<p>Now, in the 2000s and 2010s, the battle goes on under the Northern Territory <a href="http://www.humanrights.gov.au/publications/social-justice-report-2007-chapter-3-northern-territory-emergency-response-intervention">Intervention</a>.</p>
<p>Le Brun Holmes does not mention the Voyager missions in her autobiography. In 1977, she was busy campaigning for <a href="http://blogs.crikey.com.au/northern/tag/davis-daniels/">Davis Daniels</a>, an Aboriginal man from Roper River who was standing for election in the Northern Territory.</p>
<p>Perhaps Djawa, Mudpo and Waliparu never knew that their music had swept past Jupiter, Saturn, Uranus, Neptune, and this year, <a href="https://theconversation.com/voyager-1-is-leaving-the-solar-system-but-the-journey-continues-11184">into interstellar space</a> on Voyager 1.</p>
<p>But in contrast to Sagan’s well-meaning conception, this music is not the preservation in copper of a vanishing way of life. It is a mark of the resilience and adaptability of Aboriginal culture, as it sails out of the solar system, far, far beyond the morning star.
<br></p>
<p><em>This article is based on a paper presented at the Australian Space Science Conference, September 30 - October 2, 2013.</em></p><img src="https://counter.theconversation.com/content/18288/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alice Gorman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Earlier this year, NASA spacecraft Voyager 1 left our solar system after a 35-year journey, carrying with it a golden record containing sounds, images and music from Earth. Its sister craft, Voyager 2…Alice Gorman, Senior Lecturer in archaeology and space studies, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/142282013-06-17T20:35:01Z2013-06-17T20:35:01ZHumanity’s next giant leap: our heritage in space is our future too<figure><img src="https://images.theconversation.com/files/25672/original/dgn3s4tg-1371448699.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's been decades since our last foray outside Earth's orbit - but what's next for humankind?</span> <span class="attribution"><span class="source">P.O. Arnäs</span></span></figcaption></figure><p>The United Nations’ Committee on the Peaceful Uses of Outer Space is <a href="http://www.oosa.unvienna.org/oosa/en/COPUOS/index.html">meeting</a> in Vienna this week, and representatives of 74 countries will discuss, among other things, how to ensure space is maintained for peaceful purposes, and the long-term sustainability of space activities.</p>
<p>It’s a good time to reflect on how we, as the public, have contributed to the current shape of space, and the ways we can find to make space meaningful. To help us do this, let’s imagine it’s some time in the future when space travel is affordable. </p>
<p>In our spaceliner, we’ll visit a few of the most culturally significant space places in the solar system. These places are our heritage beyond the Earth’s atmosphere.</p>
<h2>Crowd-sourcing satellite science</h2>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/25661/original/n84f6x7f-1371446359.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/25661/original/n84f6x7f-1371446359.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/25661/original/n84f6x7f-1371446359.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/25661/original/n84f6x7f-1371446359.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/25661/original/n84f6x7f-1371446359.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/25661/original/n84f6x7f-1371446359.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/25661/original/n84f6x7f-1371446359.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/25661/original/n84f6x7f-1371446359.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Schematic of spacejunk in the Low Earth orbit.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Our first stop is <a href="http://en.wikipedia.org/wiki/Low_Earth_orbit">Low Earth orbit</a>, from about 200 to 2,000km above the surface of the Earth. This is where the <a href="https://theconversation.com/explainer-the-international-space-station-12565">International Space Station</a> orbits, and most of our Earth observation satellites. It’s also crawling with orbital debris or “<a href="https://theconversation.com/topics/space-junk">space junk</a>”. A collision with a piece of space junk can make a spacecraft fail or even explode. </p>
<p>But it’s not all industrial waste up there. Orbiting among the debris and the functioning satellites are historic spacecraft representing the origins of the space age. One of these pieces of space junk tells an important story of regular people engaging with space exploration.</p>
<p><a href="http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1958-002B">Vanguard 1</a>, a grapefruit-sized aluminium sphere with four antennas, is now the oldest human object in space. It was launched by the USA in 1958. It wasn’t the first object in space – that honour goes to <a href="http://history.nasa.gov/sputnik/">Sputnik 1</a> – or even the first US satellite, which was <a href="http://www.nasa.gov/mission_pages/explorer/explorer-overview.html">Explorer 1</a> – but unlike those two, it is still in orbit, and may be for <a href="http://ehlt.flinders.edu.au/archaeology/department/publications/Gorman/The%20Archaeology%20of%20Orbital%20Space.pdf">another 600 years</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/25662/original/y668yjwr-1371446572.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/25662/original/y668yjwr-1371446572.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/25662/original/y668yjwr-1371446572.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=518&fit=crop&dpr=1 600w, https://images.theconversation.com/files/25662/original/y668yjwr-1371446572.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=518&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/25662/original/y668yjwr-1371446572.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=518&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/25662/original/y668yjwr-1371446572.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=652&fit=crop&dpr=1 754w, https://images.theconversation.com/files/25662/original/y668yjwr-1371446572.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=652&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/25662/original/y668yjwr-1371446572.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=652&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Vanguard 1, pre-launch.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Vanguard 1 was aimed at promoting the idea of space as a democratic and peaceful place, so involving other nations and what we’d now call “<a href="https://theconversation.com/topics/citizen-scientists">citizen scientists</a>” was an important part of it. The USA asked countries like Australia to host tracking stations for the satellite. They also organised volunteer “<a href="http://www.universetoday.com/100744/citizen-science-old-school-style-the-true-tale-of-operation-moonwatch/">Moonwatch</a>” groups cross the world to follow the satellite with binoculars and telescopes, and gather data about its position. </p>
<p>There were several of these groups <a href="http://history.nasa.gov/SP-4202/chapter6.html">in Australia</a> too. While Vanguard 1 has great historic significance, it’s also a testament to how amateurs got involved in space exploration from the very beginning.</p>
<h2>Mixed moon messages</h2>
<p>The moon has always been a huge part of human culture, governing the <a href="https://theconversation.com/out-on-the-pull-why-the-moon-always-shows-its-face-11500">tides</a>, providing light, and as the source of <a href="http://lunar.ksc.nasa.gov/history/mythologyh.html">stories and myths</a> about how the heavens and earth came to be. </p>
<p>But in 1969, how we view the moon changed forever. On one fateful day, humans set foot on another celestial body for the first time. </p>
<p>When the US <a href="http://www.nasa.gov/mission_pages/apollo/missions/apollo11.html">Apollo 11</a> mission landed near the Sea of Tranquility, the pictures transmitted through the Australian <a href="http://www.honeysucklecreek.net/">Honeysuckle Creek tracking station</a>. The first steps were watched by <a href="http://teacher.scholastic.com/space/apollo11/moonwalk.htm">600 million people</a> across the world, frequently on televisions purchased just for this purpose. Now, we can watch them on YouTube.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RMINSD7MmT4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A giant leap indeed.</span></figcaption>
</figure>
<p>The Apollo 11 landing site, <a href="http://spacegrant.nmsu.edu/lunarlegacies/introduction.html">Tranquility Base</a>, is both an archaeological site, with the traces and remains of a unique human activity, and a symbolic site representing how we like to think of space: in the spirit of human curiosity and technological ingenuity.</p>
<p>Thanks to the <a href="http://lro.gsfc.nasa.gov/">Lunar Reconnaissance Orbiter</a>, launched in 2009, we’ve been able to get images from the satellite flying over Tranquility Base, and we can see the same view in our imaginary spaceliner. (The famous flag, alas, is no longer standing.)</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/25664/original/3t3znk42-1371446876.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/25664/original/3t3znk42-1371446876.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/25664/original/3t3znk42-1371446876.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/25664/original/3t3znk42-1371446876.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/25664/original/3t3znk42-1371446876.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/25664/original/3t3znk42-1371446876.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=522&fit=crop&dpr=1 754w, https://images.theconversation.com/files/25664/original/3t3znk42-1371446876.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=522&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/25664/original/3t3znk42-1371446876.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=522&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An image of the Apollo 11 landing site captured from just 24km above the surface by the Lunar Reconnaissance Orbiter. You can see the remnants of their first steps as dark regions around the Lunar Module (LM). The Passive Seismic Experiment Package (PSEP) provided the first lunar seismic data, and the Laser Ranging RetroReflector (LRRR) allows precise measurements to be collected to this day. You can even spot the discarded cover of the LRRR.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>The Apollo 11 landing was presented and interpreted as an action taken on behalf of all humankind, but the planting of the flag is a classic symbol of colonisation. Under the terms of the 1967 United Nations’ <a href="http://history.nasa.gov/1967treaty.html">Outer Space Treaty</a>:</p>
<blockquote>
<p>Outer space, including the moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.</p>
</blockquote>
<p>Yet clearly some would like to do just that. </p>
<p>Archaeological sites like Tranquility Base could be used in the future to demonstrate a prior or greater claim to the use of space resources – the “use it or lose it” principle. So these artefacts and material traces may have significance political implications in the future.</p>
<h2>As far as we can ‘see’</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/25660/original/bv58s95q-1371446227.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/25660/original/bv58s95q-1371446227.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/25660/original/bv58s95q-1371446227.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=568&fit=crop&dpr=1 600w, https://images.theconversation.com/files/25660/original/bv58s95q-1371446227.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=568&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/25660/original/bv58s95q-1371446227.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=568&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/25660/original/bv58s95q-1371446227.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=714&fit=crop&dpr=1 754w, https://images.theconversation.com/files/25660/original/bv58s95q-1371446227.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=714&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/25660/original/bv58s95q-1371446227.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=714&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Jupiter’s red spot, photographed by Voyager.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>But it’s time for us to move on. There have been flybys, probes and orbiters to most planets in the solar system, as well as a few asteroids and comets. We’re not doing too badly in the inner and middle solar system. </p>
<p>But as for the outer reaches, beyond Jupiter, we have barely made an impact. Only four spacecraft have ventured out this far: <a href="http://www.nasa.gov/mission_pages/pioneer/">Pioneer 10 and 11</a>, with whom we have lost contact, and <a href="https://theconversation.com/voyager-1-is-leaving-the-solar-system-but-the-journey-continues-11184">Voyager 1</a> and <a href="https://theconversation.com/an-interview-with-voyager-2-at-the-edge-of-the-solar-system-9638">Voyager 2</a>. Both are currently heading outside the solar system into interstellar space, if they have not already crossed the boundary.</p>
<p>What these tiny spacecraft mean is the entire solar system is a human place. Our senses, through these robotic avatars, have reached into places we can’t go ourselves. We have used the physical bodies of the spacecraft to imbue space with human meaning – and human culture. </p>
<p>On the Voyager spacecraft, we sent representations of human culture in case, against all the odds, someone of another species one day finds them. The spacecraft each carry a “<a href="http://voyager.jpl.nasa.gov/spacecraft/goldenrec.html">Golden Record</a>” with recordings of music and different languages. Included in the music are two Aboriginal songs, recorded by an anthropologist in the desert. Australia might only have a few objects in Earth orbit, and no space agency, but the culture of Australian Indigenous people is going to the stars.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/lapeaVqH43g?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Indigenous Australian music on Voyager’s Golden Record.</span></figcaption>
</figure>
<h2>Space is our common heritage</h2>
<p>At the moment, most nations using space resources follow the principles set down by the <a href="http://history.nasa.gov/1967treaty.html">Outer Space Treaty</a>, which, among other things, recognises</p>
<blockquote>
<p>the common interest of all mankind in the progress of the exploration and use of outer space for peaceful purposes.</p>
</blockquote>
<p>But this could change. Space is full of <a href="https://theconversation.com/lunar-boom-well-soon-be-mining-the-moon-7031">resources to be exploited</a>, such as prime orbital territories, minerals, and water, needed for the future colonisation of the solar system and to support space-based industries. </p>
<p>The <a href="http://lunar.arc.nasa.gov/results/ice/moon.htm">Moon Treaty</a>, created in 1979, stipulates the moon and other bodies in the solar system should be used for the benefit of all people and all nations. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/25663/original/p4ccj8vp-1371446787.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/25663/original/p4ccj8vp-1371446787.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/25663/original/p4ccj8vp-1371446787.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/25663/original/p4ccj8vp-1371446787.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/25663/original/p4ccj8vp-1371446787.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/25663/original/p4ccj8vp-1371446787.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/25663/original/p4ccj8vp-1371446787.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/25663/original/p4ccj8vp-1371446787.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Moon, unmined - for now.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>The Treaty promotes international sharing of resources and scientific samples. It also bans the use of the Moon for military bases or weapons testing. But, unfortunately, few of the major spacefaring nations have ratified the treaty, for a very simple reason: some <em>do</em> want to lay claim to the resources of space, and deny their use to others.</p>
<p>We all use space assets in Earth orbit for weather predictions, telephone and television, and <a href="https://theconversation.com/explainer-what-is-gps-12248">global positioning systems</a>.</p>
<p>We are stakeholders in space not just because it provides resources, but also because space development has shaped everyday life in the 20th and 21st century and these satellites and places are our history and heritage. </p>
<p>This heritage is the illustration that space does not just belong to spacefaring nations and commercial organisations. If it is important to us, it is also our right to have a say in what happens to it. And if we are not engaged in this process, then governments, the military and commercial enterprises will make those decisions for us. </p>
<p>Space heritage is what links us to our past in space, and to our future in the stars. And that future should be yours and mine to decide.
<br>
<em>This article is based on a <a href="http://www.youtube.com/watch?v=x5fn-iycWBs">TEDxSydney presentation</a> from May 4, 2013.</em></p><img src="https://counter.theconversation.com/content/14228/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alice Gorman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The United Nations’ Committee on the Peaceful Uses of Outer Space is meeting in Vienna this week, and representatives of 74 countries will discuss, among other things, how to ensure space is maintained…Alice Gorman, Lecturer, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/111842012-12-13T19:33:52Z2012-12-13T19:33:52ZVoyager 1 is leaving the solar system, but the journey continues<figure><img src="https://images.theconversation.com/files/18653/original/xpb7df3r-1355377282.jpg?ixlib=rb-1.1.0&rect=5%2C16%2C940%2C577&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Voyager 1 has come across an unexpected region of the solar system - a "magnetic superhighway".</span> <span class="attribution"><span class="source">NASA</span></span></figcaption></figure><p>At 18.5 billion kilometres from Earth, the Voyager 1 space probe is the most distant human-made object ever to leave our planet.</p>
<p>And now the spacecraft, which was launched in September 1977, has discovered a <a href="http://www.nasa.gov/mission_pages/voyager/voyager20121203.html">new region</a> at the edge of our solar system.</p>
<p>Voyager 1 is <a href="http://www.nasa.gov/mission_pages/voyager/telecon20121203.html">now entering</a> what space scientists think is the final region of the <a href="http://helios.gsfc.nasa.gov/heliosph.html">“heliosphere”</a> - the bubble of charged particles <a href="http://en.wikipedia.org/wiki/Solar_wind">the sun blows around itself</a> - before it reaches interstellar space.</p>
<p>For a spacecraft that’s now in the darkest reaches of the solar system, it’s easy to forget its mission is really all about the sun.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/18656/original/mqzmp9fn-1355378877.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/18656/original/mqzmp9fn-1355378877.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/18656/original/mqzmp9fn-1355378877.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=361&fit=crop&dpr=1 600w, https://images.theconversation.com/files/18656/original/mqzmp9fn-1355378877.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=361&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/18656/original/mqzmp9fn-1355378877.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=361&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/18656/original/mqzmp9fn-1355378877.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=454&fit=crop&dpr=1 754w, https://images.theconversation.com/files/18656/original/mqzmp9fn-1355378877.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=454&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/18656/original/mqzmp9fn-1355378877.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=454&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Voyager 1 and 2 are now in the “Heliosheath” - the outermost layer of the heliosphere where the solar wind is slowed by the pressure of interstellar gas.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>On Earth, we are at the mercy of <a href="http://solar-flares.info/">solar flares</a>, <a href="http://solarscience.msfc.nasa.gov/CMEs.shtml">coronal mass ejections</a>, and the vast amounts of electromagnetic energy and particles those phenomena fling our way. We can’t see these particles, but they can take out power grids <a href="https://theconversation.com/divert-power-to-shields-the-solar-maximum-is-coming-11228">and exposed satellites</a>.</p>
<p>There are several missions close to the sun, including NASA’s <a href="http://www.nasa.gov/mission_pages/sdo/main/index.html">Solar Dynamics Observatory</a>, which is studying the dynamics of the sun, <a href="http://en.wikipedia.org/wiki/Solar_Dynamics_Observatory#Orbit">36,000km from Earth</a>. Questions of interest include: where does the sun’s energy come from? And how is it stored and released in the sun’s atmosphere?</p>
<p>Voyager 1 is at the other end of the solar system, where the solar wind starts to meet with particles and magnetic fields from outside the solar system. And it seems that the interaction is more complex than we could have predicted.</p>
<h2>Interstellar turbulence</h2>
<p>Since December 2004 Voyager 1 has been travelling in the <a href="http://www.nasa.gov/mission_pages/voyager/pia13892.html">“heliosheath”</a> where the solar wind has slowed from supersonic speeds and become turbulent.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/5SYcU3nBj4Q?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This set of animations show NASA’s Voyager 1 spacecraft exploring a new region in our solar system called the “magnetic highway.” In this region, the sun’s magnetic field lines are connected to interstellar magnetic field lines, allowing particles from inside the heliosphere to zip away and particles from interstellar space to zoom in.</span></figcaption>
</figure>
<p>From August 2012 Voyager 1 has entered a region where these solar winds have sped up and where high-energy particles from outside the solar system are also entering the heliosphere.</p>
<p><a href="http://www.nasa.gov/mission_pages/voyager/voyager20121203.html">According to</a> Edward Stone, Voyager project scientist:</p>
<blockquote>
<p>Voyager 1 still is inside the the sun’s environment, we can now taste what it is like on the outside because the particles are zipping in and out on this magnetic highway.</p>
</blockquote>
<p>It’s an intense magnetic region that was not expected from models and will take some time to understand and interpret.</p>
<p>This discovery is remarkable in itself - more remarkable in that it was reported by an instrument designed in the early 1970s.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/18648/original/vb8hrbrk-1355374987.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/18648/original/vb8hrbrk-1355374987.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/18648/original/vb8hrbrk-1355374987.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/18648/original/vb8hrbrk-1355374987.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/18648/original/vb8hrbrk-1355374987.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/18648/original/vb8hrbrk-1355374987.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/18648/original/vb8hrbrk-1355374987.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This graphic, made from data from Voyager 1, tracks the behaviour of the sun’s magnetic field and a population of charged particles as the spacecraft moved in and out of a new region scientists are calling the “magnetic freeway ”. The top graphic (magenta) shows the intensity of the magnetic field. The intensity jumped each time Voyager 1 entered the new region. These data come from Voyager’s magnetometer. The bottom graphic (blue) shows the prevalence of lower-energy charged particles that originate from inside our heliosphere, which is the bubble of charged particles around our sun. These data come from the cosmic ray instrument. Each time Voyager 1 entered the new region, the population of these inside particles dropped. After Aug. 25, the magnetic field intensity has held steady at the same elevated level and the population of inside particles hit an all-time low and has not changed. Scientists refer to this new region as a “magnetic highway ” because here the sun’s magnetic field lines are connected to the interstellar magnetic field lines. This connection allows particles from inside the heliosphere to zip away. It also allows particles from interstellar space to zoom in.</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech/GSFC/University of Delaware</span></span>
</figcaption>
</figure>
<h2>Old-time tech</h2>
<p>Data from Voyager 1’s ten instruments, including three cameras, are stored on a <a href="http://starbrite.jpl.nasa.gov/pds/viewHostProfile.jsp?INSTRUMENT_HOST_ID=VG1">500 megabit</a> (62.5MB) tape recorder.</p>
<p>That is sufficient capacity to store about 100 images or a few graphs worth of data at a time, before it is beamed to Earth as a stream of binary data, with a theoretical upper rate of 14.4 kilobits per second, a rate far slower than a dial-up modem of 56 kilobits per second.</p>
<p>Both Voyager spacecraft – you might remember that Voyager 1 has a twin, <a href="http://starbrite.jpl.nasa.gov/pds/viewHostProfile.jsp?INSTRUMENT_HOST_ID=VG1">Voyager 2</a> – have three computers. One decodes commands from Earth and issues them to the other two, one handles data from the instruments, and one manages the spacecraft.</p>
<p>The computers have a tiny amount of memory, with memories ranging from 4 to 8KB, barely enough to run a modern car’s trip computer.</p>
<figure><a href="http://voyager.jpl.nasa.gov/science/images/jupiter2.gif"><img src="http://voyager.jpl.nasa.gov/science/images/jupiter2.gif"></a><figcaption>This time-lapse video records Voyager 1’s approach to Jupiter during a period of more than 60 Jupiter days. Source: NASA</figcaption></figure>
<h2>It’s not about the destination …</h2>
<p>On its journey to the extremities of the sun’s influence, Voyager 1 revealed Jupiter’s rings and moons to us in May 1979. It flew by Saturn, snapping photos of the planet’s rings and the mysterious hazy atmosphere of Saturn’s moon Titan.</p>
<p>Then it left the <a href="http://en.wikipedia.org/wiki/Ecliptic#Plane_of_the_Solar_System">ecliptic</a> – the plane in which most of the planets orbit the sun – heading “up”, out of the solar system.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/18650/original/tvkpqcfg-1355376631.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/18650/original/tvkpqcfg-1355376631.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=718&fit=crop&dpr=1 600w, https://images.theconversation.com/files/18650/original/tvkpqcfg-1355376631.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=718&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/18650/original/tvkpqcfg-1355376631.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=718&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/18650/original/tvkpqcfg-1355376631.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=902&fit=crop&dpr=1 754w, https://images.theconversation.com/files/18650/original/tvkpqcfg-1355376631.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=902&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/18650/original/tvkpqcfg-1355376631.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=902&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The hazy atmosphere of Saturn’s moon Titan, as seen by Voyager 1 on November 12, 1980.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>During 1998 Voyager 1 overtook the slower <a href="http://almostlucidthoughts.tumblr.com/post/33950890288/pioneer-anomaly-explained">Pioneer 10 and 11</a> crafts – which were launched to investigate Jupiter and more – becoming the furthest human artefact from Earth. It’s a record that’s likely to stand for some time, given Voyager 1 is travelling at some 520 million kilometres a year.</p>
<p>Its twin, Voyager 2, was actually launched before Voyager 1, on August 20, 1977. Its interplanetary grand tour took it past <a href="http://voyager.jpl.nasa.gov/science/jupiter.html">Jupiter</a> in July 1979, <a href="http://voyager.jpl.nasa.gov/science/saturn.html">Saturn</a> in August 1981, <a href="http://voyager.jpl.nasa.gov/science/uranus.html">Uranus</a> in June 1986 and <a href="http://voyager.jpl.nasa.gov/science/neptune.html">Neptune</a> in August 1989. Now travelling at a mere 470 million kilometres every year it is heading out of the solar system, below the ecliptic plane.</p>
<p>Both Voyagers took advantage of a planetary alignment that only occurs once every 170 years. Their trajectories enabled the Voyagers to receive a <a href="http://en.wikipedia.org/wiki/Gravity_slingshot">gravity-assisted boost</a> to their speed and direction. Without this, the trip to Neptune would have take 30 rather than ten years and they would be far short of their current positions.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/18649/original/wgqzk99y-1355376408.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/18649/original/wgqzk99y-1355376408.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=467&fit=crop&dpr=1 600w, https://images.theconversation.com/files/18649/original/wgqzk99y-1355376408.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=467&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/18649/original/wgqzk99y-1355376408.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=467&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/18649/original/wgqzk99y-1355376408.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=587&fit=crop&dpr=1 754w, https://images.theconversation.com/files/18649/original/wgqzk99y-1355376408.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=587&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/18649/original/wgqzk99y-1355376408.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=587&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Image of Saturn taken by Voyager 2.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<h2>Echoes in space</h2>
<p>Currently, our sense of the interstellar boundary comes from the merest whisper. Voyager 1 outputs 23W of radio power - barely even a glow by light-bulb standards. We hear this whisper on Earth at the limit of NASA’s <a href="http://www.cdscc.nasa.gov/Pages/antennas.html">Deep Space Network</a>, requiring the pooled resources of two antennae at whichever site is in contact, at a ghostly 6x10<sup>-18</sup> W - an almost unimaginably small signal.</p>
<p>This remarkable spacecraft represents the extent of our physical senses in the solar system. From the surface of the Earth, our astronomers can remotely sense faraway galaxies and observe intergalactic events far into the distance and deep in time.</p>
<p>But closer to home, there’s so much we don’t know. And opportunities to continue our exploration outside the bubble are limited.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/18652/original/936ysd4j-1355376963.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/18652/original/936ysd4j-1355376963.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/18652/original/936ysd4j-1355376963.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=597&fit=crop&dpr=1 600w, https://images.theconversation.com/files/18652/original/936ysd4j-1355376963.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=597&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/18652/original/936ysd4j-1355376963.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=597&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/18652/original/936ysd4j-1355376963.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=750&fit=crop&dpr=1 754w, https://images.theconversation.com/files/18652/original/936ysd4j-1355376963.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=750&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/18652/original/936ysd4j-1355376963.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=750&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Voyager 1’s batteries are expected to run out of power towards 2050.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<h2>Powering down</h2>
<p>Voyager 1 has only five functioning instruments left from its original ten. As the power in its plutonium-238 batteries runs down towards 2050, the instruments will be turned off one by one, much like house lights winking out in the night.</p>
<p>Voyager 1’s whisper will at last fall silent and the same fate awaits Voyager 2.</p>
<p>How will we feel when we can no longer “see” beyond the enigmatic borders of the sun’s influence? How will we feel when the solar system appears to contract around us?</p>
<p>Of course, even when the two Voyagers stop communicating with Earth, their journey will continue apace, pushing beyond the confines of our solar system into the unfathomable vastness beyond.</p><img src="https://counter.theconversation.com/content/11184/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>At 18.5 billion kilometres from Earth, the Voyager 1 space probe is the most distant human-made object ever to leave our planet. And now the spacecraft, which was launched in September 1977, has discovered…Kevin Orrman-Rossiter, Graduate Student, History & Philosophy of Science, The University of MelbourneAlice Gorman, Senior Lecturer in archaeology and space studies, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/96382012-10-14T19:19:40Z2012-10-14T19:19:40ZAn interview with Voyager 2 … at the edge of the solar system<figure><img src="https://images.theconversation.com/files/16001/original/5f8rvktm-1349052177.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's not everyday you get to chat with a spacecraft that's nearing the edge of the solar system.</span> <span class="attribution"><span class="source">NASA</span></span></figcaption></figure><p>Interviewing a spacecraft isn’t something one does every day. It certainly wasn’t an option back in the late 1970s, when Voyager 1 and 2 set off on a mission like no other before or since: to visit some of the most mysterious planets in the solar system, and then to continue out and on, into the galaxy.</p>
<p>But just recently I was lucky enough to “interview” Voyager 2, via its <a href="https://twitter.com/NASAVoyager2">Twitter account</a>, on behalf of both spacecraft.</p>
<p><a href="http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Voyager_2">Voyager 2</a> left Earth first, on August 20 1977, followed by <a href="http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Voyager_1">Voyager 1</a> on September 5. Since then the twin spacecraft have revealed many secrets about our solar system.</p>
<p>Earlier this year, it looked as if Voyager 1 was about to become the first human object to ever leave the solar system. The craft was approaching the <a href="http://en.wikipedia.org/wiki/Heliosphere">heliopause</a> – the boundary point at which the solar wind meets the interstellar wind. But a recent <a href="http://www.nature.com/nature/journal/v489/n7414/full/nature11441.html">study published in Nature</a> suggests this moment may yet be some years off. </p>
<p>In the meantime, the spacecraft – it seems – are in good spirits.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/15788/original/tnkdxbqd-1348464152.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/15788/original/tnkdxbqd-1348464152.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/15788/original/tnkdxbqd-1348464152.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/15788/original/tnkdxbqd-1348464152.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/15788/original/tnkdxbqd-1348464152.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/15788/original/tnkdxbqd-1348464152.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/15788/original/tnkdxbqd-1348464152.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Voyager 2.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p><strong>What is your position in relation to Earth right now?</strong></p>
<p>I’m about 13.5 light hours from Earth, or 14,570,000,000km. Remember, I travel about 1,300,000km each day!</p>
<p>I am in the southern skies, at <a href="http://en.wikipedia.org/wiki/Right_ascension">right ascension</a> 19h50m45.6s and <a href="http://en.wikipedia.org/wiki/Declination">declination</a> -54°49'12" – about halfway between the stars <a href="http://en.wikipedia.org/wiki/Eta_Ophiuchi">η Ophiuchus</a> and <a href="http://en.wikipedia.org/wiki/Pavo_(constellation)">α Pavo</a>.</p>
<p>Here’s another way to think about my position. Take any sized ball (cricket, football, etc.) and hold it at a distance where it just covers the sun’s disc. You now have the basis for a scale model of the solar system.</p>
<p>If the sun were the size of whatever ball you are using, your eyeball is now at the scaled distance of Earth, or one <a href="http://en.wikipedia.org/wiki/Astronomical_unit">Astronomical Unit</a> (AU). Using this scale, I am about 97 times as far from the ball as your eyeball.</p>
<p><strong>What is the most significant thing you have taught us about the solar system?</strong></p>
<p>That is a very difficult question. Most of what we know about the giant planets comes from our data. That said, later work based on the <a href="http://www.nasa.gov/mission_pages/cassini/main/index.html">Cassini</a> and <a href="http://solarsystem.nasa.gov/galileo">Galileo</a> missions has clarified several mysteries we Voyagers first uncovered.</p>
<p>From simple things – such as allowing better mass estimates to be calculated for the planets and their moons, and discovering new moons during every planetary encounter – to things as amazing as <a href="http://www.astro.washington.edu/courses/labs/clearinghouse/labs/Io/volcanoes_io.html">Io’s volcanoes</a>, <a href="http://www.nasa.gov/mission_pages/voyager/PIA_02292_07712.html">Saturn’s kinked rings</a>, <a href="http://suite101.com/article/shepherd-moons-planetary-rings-a44945">shepherd moons</a> – which orbit near Saturn’s rings – and <a href="http://www.space.com/2165-saturns-ring-spokes-depend-sun-angle-study.html">ring spokes</a>, to <a href="http://www.universetoday.com/22067/weather-on-neptune/">unexpectedly vigorous weather on Neptune</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/15791/original/862ffz7p-1348464425.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/15791/original/862ffz7p-1348464425.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=591&fit=crop&dpr=1 600w, https://images.theconversation.com/files/15791/original/862ffz7p-1348464425.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=591&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/15791/original/862ffz7p-1348464425.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=591&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/15791/original/862ffz7p-1348464425.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=743&fit=crop&dpr=1 754w, https://images.theconversation.com/files/15791/original/862ffz7p-1348464425.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=743&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/15791/original/862ffz7p-1348464425.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=743&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of the Voyager program’s biggest discoveries was of Neptune’s strong weather, pictured here from Voyager 2.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Furthermore, no other spacecraft have tasted and bathed in the outer reaches of our solar system as Voyager 1 and I have. Without us, scientists could only speculate what it is like out here.</p>
<p>But I like to think of our greatest achievement as simply laying down a path that others could follow. After all, we are the very first functioning human-made objects to venture this far out from the sun, and into interstellar space!</p>
<p><strong>What was it like to cross the termination shock in 2007 (the point at which the solar wind slows down to subsonic speed)?</strong></p>
<p>I was elated, but also surprised. Elated, because I had to put up with Voyager 1’s crowing since she crossed in 2004! Surprised, because I crossed early, at a much closer distance than Voyager 1.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/15789/original/63f5t3zm-1348464292.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/15789/original/63f5t3zm-1348464292.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/15789/original/63f5t3zm-1348464292.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/15789/original/63f5t3zm-1348464292.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/15789/original/63f5t3zm-1348464292.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/15789/original/63f5t3zm-1348464292.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/15789/original/63f5t3zm-1348464292.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p><strong>How will you know when you have crossed the heliopause and are heading into interstellar space?</strong></p>
<p>Gauging from our past experiences, one indication might be our science teams’ levels of confusion! Each of these crossings has had some rather unexpected features, which made the science teams very cautious about announcing definitive crossings. </p>
<p>For instance, the temperature of the solar wind ions (charged particles) outside the termination shock was lower than models had predicted … by a factor of ten!</p>
<p>More recently, Voyager 1’s <a href="http://www.nasa.gov/mission_pages/voyager/heliosphere-surprise.html">findings of magnetic “bubbles”</a> was also unexpected. The models predicted a much smoother “sheet” where the flow of winds from the sun and stars was parallel, rather than the turbulent region we actually encountered.</p>
<p>I expect a slowing in the observed particle speeds, and changes in their directions once we reach the heliopause. Eventually this should settle down again to a smooth flow, but this time it will be a wind from stars other than the sun!</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Tpqm_JK5Cqk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p><strong>What do you remember about Earth?</strong></p>
<p>I remember awakening at the Jet Propulsion Laboratory (JPL), being tested thoroughly in a very tall and white room, and then being packaged up very carefully and taken all the way across the continent to the Kennedy Space Center.</p>
<p>It was much more humid there, and I was tested again before I was covered up with the <a href="http://en.wikipedia.org/wiki/Titan_IIIE">Titan IIIE Centaur fairing</a>. Even though I couldn’t see, I could hear. I heard all sorts of wonderful sounds: wind and rain. I remember the rain in particular.</p>
<p>Then, of course, I remember leaving Earth – the launch itself. It was not such a good experience, because I got very dizzy, and nearly passed out. Ground control at JPL was very worried, but I eventually calmed down and was able to let JPL know that I was fine. This was the first example of my “safing routines” coming into action.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/15790/original/w9nzkbzd-1348464341.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/15790/original/w9nzkbzd-1348464341.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=601&fit=crop&dpr=1 600w, https://images.theconversation.com/files/15790/original/w9nzkbzd-1348464341.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=601&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/15790/original/w9nzkbzd-1348464341.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=601&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/15790/original/w9nzkbzd-1348464341.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=755&fit=crop&dpr=1 754w, https://images.theconversation.com/files/15790/original/w9nzkbzd-1348464341.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=755&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/15790/original/w9nzkbzd-1348464341.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=755&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of Voyager’s golden records.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p><strong>Your fuel and power are estimated to run out around 2025. What happens then?</strong></p>
<p>Actually it’s just my electrical power – the fuel for adjusting my <a href="http://en.wikipedia.org/wiki/Aircraft_attitude">attitude</a> (orientiation) should last past the 2030s, though I can’t even access that fuel once I run out of electricity.</p>
<p>As my available electrical power drops, I will not have sufficient margin to run all of my instruments at the same time and, starting in 2020, folks back on Earth will have to choose which of my instruments to keep running.</p>
<figure><a href="http://voyager.jpl.nasa.gov/science/images/jupiter2.gif"><img src="http://voyager.jpl.nasa.gov/science/images/jupiter2.gif" width="440px"></a><figcaption>Voyager 1’s approach to Jupiter over a period of more than 60 Jupiter days.</figcaption></figure>
<p>This will be done via a process very similar to that used for planning the planetary encounters, since there was a very similar set of constraints then: only a certain number of things could be done at once, and priorities had to be set well in advance so the appropriate sequences could be programmed.</p>
<p>This is done via a consultative process between the science and engineering teams in order to reach the best science results within the power limits.</p>
<p>Eventually, of course, there will be insufficient power to run any single science instrument, and the science instrument imperatives vanish. Sufficient power will remain for radio ranging for some time after that, but at this point it is unclear what, if any, science value these ranging data would have.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/lapeaVqH43g?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Voyager 1 and 2 both carry a golden record featuring sounds from Earth, including the Aboriginal song Morning Star.</span></figcaption>
</figure>
<p><strong>If you could choose a piece of music to represent what you “see” or how you feel at this point in time, what would it be?</strong></p>
<p>Oh, I suppose I always go back to <a href="http://www.youtube.com/watch?v=cWnmCu3U09w">Thus Spoke Zarathustra</a> (the theme tune from 2001: A Space Odyssey) because of its association with space, and especially with floating, thanks to Stanley Kubrick. </p>
<p>However, many of my tweeps have suggested all sorts of new music to me that I have enjoyed. Sadly, none of these newer compositions are on our golden discs, of course.</p>
<p><em>The author would like to thank Dr Paul Filmer from the National Science Foundation (US) and NASA’s Jet Propulsion Laboratory (JPL) for agreeing to this interview and speaking on behalf of Voyager 2.</em></p>
<p><em>Voyager 2 tweets at <a href="https://twitter.com/NASAVoyager2">@NASAVoyager2</a>, and you can follow <a href="https://twitter.com/NASAVoyager">@NASAVoyager</a> for official tweets from JPL. The full text of the interview can be read at Alice’s blog <a href="http://zoharesque.blogspot.com.au/2012/09/the-ghost-in-machine-interview-with_10.html">Space Age Archaeology</a>.</em></p><img src="https://counter.theconversation.com/content/9638/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alice Gorman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Interviewing a spacecraft isn’t something one does every day. It certainly wasn’t an option back in the late 1970s, when Voyager 1 and 2 set off on a mission like no other before or since: to visit some…Alice Gorman, Lecturer, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.