tag:theconversation.com,2011:/columns/bryan-gaensler-598The enthusiastic astronomer – The Conversation2016-04-27T10:10:44Ztag:theconversation.com,2011:article/582002016-04-27T10:10:44Z2016-04-27T10:10:44ZHow to capture the violent tumult of our roiling universe, moment by moment<figure><img src="https://images.theconversation.com/files/119698/original/image-20160421-27019-12k6yp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">All is not calm in the cosmos.</span> <span class="attribution"><a class="source" href="http://www.nasa.gov/content/goddard/hubble-stares-into-the-crammed-center-of-messier-22">ESA/Hubble and NASA</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>The hustle and bustle of daily life is a stark contrast to the tranquility of the night sky.</p>
<p>The stars are the same, year after year. So much so that many of the very names we use for the <a href="https://www.naic.edu/%7Egibson/starnames/starnames.html">stars</a> and <a href="http://www.skyandtelescope.com/astronomy-resources/constellation-names-and-abbreviations/">constellations</a> are thousands of years old. <a href="http://www.ancient.eu/Greek_Astronomy/">Ancient Greek</a> and <a href="http://www.metmuseum.org/toah/hd/astr/hd_astr.htm">Arabic astronomers</a> had almost exactly the same view of the heavens that we have today: the stars do not seem to change.</p>
<p>But this is a lie.</p>
<p>We now know that the night sky is a <a href="https://www.youtube.com/watch?v=eU12jeGAUSg">seething, bubbling tableau</a>. Look up, and unseen by your eye a vast number of stars are erupting, exploding or being torn apart.</p>
<p>How can the universe be so tumultuous, when it seems so peaceful? Because with our limited human vision we see only the tiny brightest tip of what the cosmos has to offer. Look deeper, and violence abounds.</p>
<h2>Stars are far from static</h2>
<p>A growing number of astronomers now devote their careers to what is known as “<a href="http://blogs.discovermagazine.com/crux/2014/01/06/how-a-new-type-of-astronomy-investigates-the-most-mysterious-objects-in-the-universe/">time-domain astronomy</a>” – the search for celestial bodies that appear, disappear or change with time. The goal is to catch stars in the very act of brightening or fading, and to use these changes to learn more about the cosmos.</p>
<p>Flashes and flares in the sky usually represent <a href="https://what-if.xkcd.com/73/">catastrophic releases of energy</a>, under conditions <a href="http://solomon.as.utexas.edu/magnetar.html#Strong_Magnetic_Fields">far more extreme</a> than we could ever hope to reproduce in laboratories here on Earth. To see the sky change is to open a window into exotic and fundamental physics that we could never otherwise study.</p>
<p>The catch is that time-domain astronomy is a cosmic guessing game, with seemingly impossible odds stacked against us.</p>
<h2>Where to focus our shared sights</h2>
<p>The fundamental problem is that we don’t know in advance where the next change in the heavens is going to happen. So even if we look at the sky all the time, chances are we won’t be looking in the right place.</p>
<p>For example, suppose that once a night, somewhere in the universe, a star abruptly ends its life in a <a href="http://www.space.com/6638-supernova.html">colossal supernova explosion</a>. We would very much like to see this happen, but we cannot possibly know which of billions of stars <a href="http://www.universetoday.com/110394/which-star-will-explode-next/">will be the next to go</a>.</p>
<p>Maybe we should just stare through our telescopes, night after night, and hope for the best? Unfortunately, most modern telescopes have tiny fields of view, so it’s almost certain that we will always be looking in the wrong direction. The <a href="https://www.nasa.gov/mission_pages/hubble/story/index.html">Hubble Space Telescope</a>, arguably the most powerful telescope ever built, has a field of view that covers <a href="http://www.nasa.gov/mission_pages/hubble/science/xdf.html">just 0.000008 percent of the sky</a> at any one time. Patiently point Hubble in a random direction once every 24 hours, hoping that you’ll see the one supernova in the universe that happened to occur that night, and you’ll average tens of thousands of years before you’re lucky enough to catch one in the act. </p>
<p>Astronomers have thus had to come up with a range of clever solutions, all aimed at dealing with the vastness of the sky, and geared toward finding the needle in the cosmic haystack.</p>
<p>Perhaps unique in all fields of research, astronomy is built on strong <a href="http://rosetta.jpl.nasa.gov/news/role-amateur-astronomers-rosetta%E2%80%99s-mission">partnerships between amateurs and professionals</a>. Thousands of amateurs <a href="https://sciencebits.wordpress.com/2008/09/01/bob-evans-supernova-hunter/">patrol the skies</a> with their own modest-sized telescopes night after night, looking for anything unusual. With so many eyes on the sky at once, the chances of quickly finding any changes in the heavens are pretty good.</p>
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<a href="https://images.theconversation.com/files/119697/original/image-20160421-26981-sr9z6l.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/119697/original/image-20160421-26981-sr9z6l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119697/original/image-20160421-26981-sr9z6l.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=329&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119697/original/image-20160421-26981-sr9z6l.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=329&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119697/original/image-20160421-26981-sr9z6l.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=329&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119697/original/image-20160421-26981-sr9z6l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=414&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119697/original/image-20160421-26981-sr9z6l.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=414&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119697/original/image-20160421-26981-sr9z6l.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=414&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 aerial view of the Murchison Widefield Array, which has a drastically wider view of the sky than any telescope that’s come before.</span>
<span class="attribution"><a class="source" href="http://mwatelescope.org/multimedia/images">Murchison Widefield Array</a></span>
</figcaption>
</figure>
<p>Astronomers have also built new types of telescopes, with spectacular fish-eye lens capabilities to image enormous swaths of the sky at once. For example, the forthcoming <a href="http://www.lsst.org/">Large Synoptic Survey Telescope</a> will utilize a 3,200-megapixel camera to provide a field of view more than 3,000 times larger than that of Hubble. And a new radio telescope, the <a href="http://mwatelescope.org/">Murchison Widefield Array</a>, has a view of the sky larger than Hubble’s by a factor of 500,000. While we will still not know exactly where to look to see the next explosion or disruption, the odds are greatly increased when you’re looking through a massively wide-angle lens.</p>
<p>Once an astronomer finds something unexpected in the sky, the most urgent thing is to let everyone else know too, so that they can also study it before it fades away.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"723551606726336512"}"></div></p>
<p>Sophisticated <a href="http://www.astronomerstelegram.org/">electronic alert networks</a> have thus been developed, which allow any registered user to <a href="http://gcn.gsfc.nasa.gov/">instantly notify</a> everyone else as to what they’ve seen and where to look. The truly dedicated sleep with their phones by their beds, ready to be awakened by an automatic alert calling them to action.</p>
<p>Upon receiving such an alert, astronomers will swing their telescopes to the relevant patch of the sky, eager to capture their own contribution to the aftermath of the event before it fades away. Every day, a <a href="http://gcn.gsfc.nasa.gov/other/G184098.gcn3">global game of “whack-a-mole”</a> takes place as these alerts crisscross the globe and call stargazers to action.</p>
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<a href="https://images.theconversation.com/files/119693/original/image-20160421-26970-1g4ic1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/119693/original/image-20160421-26970-1g4ic1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119693/original/image-20160421-26970-1g4ic1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119693/original/image-20160421-26970-1g4ic1x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119693/original/image-20160421-26970-1g4ic1x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119693/original/image-20160421-26970-1g4ic1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=590&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119693/original/image-20160421-26970-1g4ic1x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=590&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119693/original/image-20160421-26970-1g4ic1x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=590&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 star quake’s massive blast of energy.</span>
<span class="attribution"><a class="source" href="http://www.nasa.gov/multimedia/imagegallery/image_feature_626.html">NASA</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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</figure>
<h2>Accumulating fiery findings</h2>
<p>What have we learned from time-domain astronomy?</p>
<p>We have seen <a href="http://www.nytimes.com/2005/02/20/science/space/dying-star-flares-up-briefly-outshining-rest-of-galaxy.html">colossal distant star quakes</a>, releasing more energy than the sun can produce in a quarter of a million years. We have seen stars cry out their <a href="http://www.space.com/12719-black-hole-swallows-star-nasa-swift.html">final farewell in a flash of light</a> as they fall into the maw of a giant black hole. We have seen <a href="http://www.abc.net.au/news/2016-01-22/dark-noodles-discovered-in-the-milky-way/7105344">invisible noodle-like tubes of gas</a>, drifting in front of galaxies, flaring and distorting their light like a funhouse mirror. And we have borne witness to the <a href="http://www.space.com/5826-scream-black-hole-birth-detected-halfway-universe.html">birth cries of newborn black holes</a>, formed when a star’s nuclear furnace shuts down and gravity takes over.</p>
<p>The universe is a dynamic, violent, exciting place. We have begun a heady new era, in which the sky changes in real time as we watch with amazement.</p><img src="https://counter.theconversation.com/content/58200/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Bryan Gaensler receives funding from the Natural Sciences and Engineering Research Council of Canada and from the Canada Research Chairs Program.</span></em></p>Stargazing seems such a quiet, calm activity. But whether our eyes can see or not, those stars out there are in constant flux. Time-domain astronomy studies how cosmic objects change with time.Bryan Gaensler, Director, Dunlap Institute for Astronomy and Astrophysics, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/547992016-02-18T10:45:09Z2016-02-18T10:45:09ZEying exomoons in the search for E.T.<figure><img src="https://images.theconversation.com/files/111700/original/image-20160216-30543-q8x12.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If you're looking for life, you'd do well to look for some moons.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/mualphachi/10353071926">Maxwell Hamilton</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>When I was young, the only planets we knew about were the ones in our own solar system.</p>
<p>Astronomers presumed that many of the other stars in the night sky had planets too, but this was sheer speculation. We could never know for sure, the thinking went, because such planets were ridiculously small and faint. To ever see or study them seemed a complete impossibility. “Extrasolar planets,” or “exoplanets,” were a <a href="http://starchive.cs.umanitoba.ca/?locations/planets-moons">staple of science fiction</a>, but not of professional astrophysics.</p>
<p>It’s hard to believe that there was once such a simple time. The first <a href="http://www2.astro.psu.edu/users/alex/pulsar_planets.htm">definitive detection of an exoplanet</a> was in 1991, identified by the tiny wobbles experienced by the parent star as its exoplanet swung around it. Since then, the <a href="https://commons.wikimedia.org/wiki/File:Exoplanet_Discovery_Methods_Bar.png">field has exploded</a>. There are now around <a href="http://exoplanets.org/">1,600 confirmed exoplanets</a>, with almost 4,000 other known candidates. There are exoplanets <a href="http://www.nasa.gov/mission_pages/kepler/news/kepler-37b.html">smaller than Mercury</a>, and others <a href="http://news.nationalgeographic.com/news/2009/08/090817-new-planet-orbits-backward.html">many times bigger than Jupiter</a>. Their orbits around their parent stars range from <a href="http://www.space.com/22451-fastest-earth-size-lava-planet-kepler78b.html">a few hours</a> to <a href="http://www.space.com/20231-giant-exoplanets-hr-8799-atmosphere-infographic.html">hundreds of years</a>. And the ones we know about are just a tiny fraction of the <a href="http://www.space.com/19103-milky-way-100-billion-planets.html">more than 100 billion exoplanets</a> we now believe are spread throughout our Milky Way galaxy.</p>
<p>But while the golden age of exoplanets has barely begun, an exciting additional chapter is also taking shape: the hunt for exomoons.</p>
<h2>Beyond Earth-like planets to exomoons</h2>
<p>An exomoon is a moon orbiting a planet, which in turn is orbiting another star. You may not have ever heard of exomoons before now. But if you’re a fan of films such as “<a href="http://www.avatarmovie.com">Avatar</a>,” “<a href="http://www.starwars.com/films/star-wars-episode-vi-return-of-the-jedi">Return of the Jedi</a>” or “<a href="http://www.projectprometheus.com/">Prometheus</a>,” this should be familiar territory: in all three cases, most of the action takes place on an exomoon.</p>
<p>But what about real life? How many exomoons do we know of? At the moment, zero.</p>
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<a href="https://images.theconversation.com/files/111701/original/image-20160216-19232-10h7to6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/111701/original/image-20160216-19232-10h7to6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111701/original/image-20160216-19232-10h7to6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111701/original/image-20160216-19232-10h7to6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111701/original/image-20160216-19232-10h7to6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111701/original/image-20160216-19232-10h7to6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111701/original/image-20160216-19232-10h7to6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111701/original/image-20160216-19232-10h7to6.jpeg?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">Endor: not all exomoons come with ewoks.</span>
<span class="attribution"><a class="source" href="http://www.starwars.com/databank/ewok">Star Wars: Episode VI Return of the Jedi</a></span>
</figcaption>
</figure>
<p>But <a href="http://www.space.com/28918-exomoons-alien-life-search.html">the race is on</a> to find the real-life analogs of <a href="http://starwars.wikia.com/wiki/Endor">Endor</a> and <a href="http://james-camerons-avatar.wikia.com/wiki/Pandora">Pandora</a>.</p>
<p>You might think searching for tiny rocks orbiting distant planets around faint stars hundreds or thousands of light years away is the ultimate example of an obscure academic pursuit. But exomoons are poised to become a big deal.</p>
<p>The whole reason exoplanets are exciting is that they’re a path to answering one of the grandest questions of all: “<a href="https://www.ted.com/playlists/82/are_we_alone_in_the_universe">Are we alone?</a>” As we find more and more exoplanets, we eagerly ask <a href="http://www.universetoday.com/120982/what-is-the-habitable-zone/">whether life could exist there</a>, and whether <a href="https://en.wikipedia.org/wiki/Earth_Similarity_Index">this planet is anything like Earth</a>. However, so far we’ve yet to find an exact match to Earth, nor can we yet really know for sure whether any exoplanet, Earth-like or otherwise, hosts life.</p>
<h2>Enter exomoons in the search for life</h2>
<p>There are several reasons why exomoons, these little distant worlds, may be the key to finding life elsewhere in the universe.</p>
<p>First, there’s the stark reality that life on Earth may not have happened at all <a href="http://www.astrobio.net/topic/exploration/moon-to-mars/if-we-had-no-moon/">without the starring role played by our own moon</a>.</p>
<p>The Earth’s axis is tilted by 23.5 degrees relative to its motion around the sun. This tilt <a href="http://www.windows2universe.org/earth/climate/cli_seasons.html">gives us seasons</a>, and because this tilt is relatively small, seasons on Earth are mild: most places never get impossibly hot or unbearably cold. One thing that has been crucial for life is that this tilt has stayed the same for very long periods: for millions of years, the angle of tilt has <a href="http://ffden-2.phys.uaf.edu/212_fall2003.web.dir/Beth_Caissie/obliquity.htm">varied by only a couple of degrees</a>.</p>
<p>What has kept the Earth so steady? The <a href="http://www.space.com/12464-earth-moon-unique-solar-system-universe.html">gravity of our moon</a>.</p>
<p>In contrast, Mars only has <a href="http://mars.nasa.gov/allaboutmars/extreme/moons/">two tiny moons</a>, which have negligible gravity. Without a stabilizing influence, Mars has gradually tumbled back and forth, its <a href="http://www.spacedaily.com/news/mars-water-science-00d.html">tilt ranging between 0 and 60 degrees</a> over millions of years. Extreme changes in climate have resulted. Any Martian life that ever existed would have found the need to continually adapt very challenging.</p>
<p>Without our moon, the Earth, too, would likely have been <a href="http://sciencenordic.com/what-would-we-do-without-moon">subject to chaotic climate conditions</a>, rather than the relative certainty of the seasons that stretches back deep into the fossil record.</p>
<p>The gravity of the <a href="http://www.techtimes.com/articles/80715/20150831/moon-affects-tides.htm">moon also produces the Earth’s tides</a>. Billions of years ago, the ebb and flow of the oceans produced an alternating cycle of high and low salt content on ancient rocky shores. This recurring cycle <a href="https://www.newscientist.com/article/dn4786-no-moon-no-life-on-earth-suggests-theory/">could have enabled the unique chemical processes</a> needed to generate the first DNA-like molecules.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/111704/original/image-20160216-19232-15pbxgu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/111704/original/image-20160216-19232-15pbxgu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111704/original/image-20160216-19232-15pbxgu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=535&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111704/original/image-20160216-19232-15pbxgu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=535&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111704/original/image-20160216-19232-15pbxgu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=535&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111704/original/image-20160216-19232-15pbxgu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=672&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111704/original/image-20160216-19232-15pbxgu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=672&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111704/original/image-20160216-19232-15pbxgu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=672&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Moons might contribute to a planet’s habitability.</span>
<span class="attribution"><a class="source" href="http://www.nasa.gov/jpl/cassini/pia18322/triple-crescents">NASA/JPL-Caltech/Space Science Institute</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Exomoons might have Earth-like environments</h2>
<p>Overall, as we continue to hunt for another Earth somewhere out there, it seems likely that a twin of Earth, but without a moon accompanying it, would not look familiar. Finding exomoons is a key part of finding somewhere like here.</p>
<p>Meanwhile, we shouldn’t be discouraged by the fact that most exoplanets found so far are <a href="http://www.space.com/18522-super-jupiter-alien-planet-photo.html">bloated gaseous beasts</a>, with hostile environments unlikely to support life as we know it. What we don’t know yet, crucially, is whether these exoplanets have moons. This prospect is exciting, because exomoons are expected to be smaller rocky or icy bodies, <a href="http://www.astrobio.net/news-exclusive/exomoons-abundant-sources-habitability/">possibly hosting oceans and atmospheres</a>.</p>
<p>This is hardly speculation: Titan (a moon of Saturn) has <a href="http://saturn.jpl.nasa.gov/science/index.cfm?SciencePageID=75">a thick atmosphere</a> even denser than Earth’s, while <a href="http://www.earthmagazine.org/article/pair-moons-underground-oceans">underground oceans</a> are thought to exist on <a href="http://www.nasa.gov/press-release/cassini-finds-global-ocean-in-saturns-moon-enceladus/">Enceladus</a> (another moon of Saturn) and on <a href="http://www.bbc.com/earth/story/20150326-europa-may-be-home-to-alien-life">Europa</a> and <a href="http://www.space.com/28807-jupiter-moon-ganymede-salty-ocean.html">Ganymede</a> (both moons of Jupiter). Thus, if there is any other life out there somewhere, it may well not be found on a distant planet, but <a href="http://www.iflscience.com/space/exomoons-might-be-secret-alien-life">on a distant moon</a>.</p>
<p>The <a href="https://www.newscientist.com/article/dn27180-race-to-find-the-first-exomoon-heats-up/">hunt is on</a>. While exomoons are too faint to see directly, astronomers are deploying <a href="http://www.astrobio.net/news-exclusive/new-exomoon-hunting-technique-could-find-solar-system-like-moons/">ingenious indirect techniques</a> in their searches. Those moons are assuredly out there by the billions – and soon we will find them. It won’t be too much longer before these tiny worlds help us answer huge questions.</p><img src="https://counter.theconversation.com/content/54799/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Bryan Gaensler receives funding from the Natural Sciences and Engineering Research Council of Canada.</span></em></p>As the list of known planets beyond our solar system grows, the search for their moons is intensifying. One reason: they might hold the key to finding life elsewhere in the universe.Bryan Gaensler, Director, Dunlap Institute for Astronomy and Astrophysics, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/445552015-07-13T22:57:29Z2015-07-13T22:57:29ZWorkaholism isn’t a valid requirement for advancing in science<figure><img src="https://images.theconversation.com/files/88257/original/image-20150713-11825-5rio7i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What time do you think it's safe for me to leave work?</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-219172816/stock-photo-woman-businesswoman-under-stress-missing-her-deadlines.html">Overwork image via www.shutterstock.com</a></span></figcaption></figure><p>In the late 1990s, I landed a position as a postdoctoral researcher at the storied <a href="http://web.mit.edu/">Massachusetts Institute of Technology</a>.</p>
<p>At first, I would turn up to work around 9 am, and would head home around 5 pm. But before too long, I noticed that many of the other scientists were already in at work by 9, and that the same people were still in the lab at 5.</p>
<p>“Hmm,” I thought. “I’m at MIT now. I need to lift my game.”</p>
<p>I began arriving an hour earlier, and staying an hour later. But at 8 am, the same people were already in working. And at 6 pm, they showed no signs of going home.</p>
<p>I’m the competitive sort, so I rose to the challenge. I cranked it up to 12-hour days, 7 am to 7 pm. But the same people were still in there before me and stayed after me.</p>
<p>This silent arms race escalated for another six months, at great personal strain.</p>
<p>But then I came to a realization. The additional hours were not translating into extra progress, but rather only into extra exhaustion. So I went back to working eight-hour days, before moving on a few years later to a faculty position at Harvard. </p>
<p>Almost 20 years later, I’m now an institute director at the University of Toronto. A big focus of my efforts is to boost the careers, well-being and success of my institute’s students and postdocs.</p>
<p>It was thus with some surprise and disappointment that I read this week <a href="http://www.sciencemag.org/content/349/6244/206.full">some questionable career advice</a> from another University of Toronto department head. My colleague argues that to reach his current senior position, he worked 16-17 hours per day as an early career scientist. He notes that his children spent weekends playing in the lobby, and that his wife (also a PhD scientist) did most of the parenting.</p>
<p>Like the <a href="http://jjcharfman.tumblr.com/post/33151387354/a-motivational-correspondance">infamous department email sent from the professors to the PhD students</a> recommending 80-100 hour work weeks, this presents misleading and incorrect advice on how to succeed in research, in academia, and in careers and life in general.</p>
<p>Here are the actual facts.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/88264/original/image-20150713-11825-1wkq37l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/88264/original/image-20150713-11825-1wkq37l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/88264/original/image-20150713-11825-1wkq37l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88264/original/image-20150713-11825-1wkq37l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88264/original/image-20150713-11825-1wkq37l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88264/original/image-20150713-11825-1wkq37l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88264/original/image-20150713-11825-1wkq37l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88264/original/image-20150713-11825-1wkq37l.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">Are these PhD grads smiling because they know how to work smarter, not longer?</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/georgiasouthern/9087212906">Georgia Southern</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Working longer hours <a href="http://fortune.com/2011/06/06/how-many-hours-should-you-be-working/">leads to poorer productivity</a>. If you’re trying to impress people and move up the ranks, the solution isn’t to work longer, but <a href="http://www.refinethemind.com/21-time-management-tips/">to work smarter</a>. Learn to manage your time, to limit the endless spiral of emails and meetings, and to improve your efficiency.</p>
<p>The sustained schedule of 80- to 100-hour working weeks, which the macho male academic claims has got him where he is today, is a myth. <a href="http://www.nytimes.com/2015/05/05/upshot/how-some-men-fake-an-80-hour-workweek-and-why-it-matters.html">Men exaggerate or misjudge</a> the number of hours they work. There are simple <a href="http://www.fastcompany.com/3024249/10-time-tracking-apps-that-will-make-you-more-productive-in-2014">apps and tools to track</a> your productive working hours and working patterns: the answers <a href="http://www.astrobetter.com/blog/2012/10/10/not-what-we-want/#comment-91054">may surprise you</a>.</p>
<p>While it might be mathematically possible to work 17-hour days for extended periods, there are then huge compromises on diet, fitness and rest. However, poor nutrition, lack of exercise and bad sleep hygiene are all major <a href="http://www.fhpcc.com/the-role-of-exercise-nutrition-and-sleep-in-the-battle-against-depression/">contributing factors to depression</a> and general ill health. Indeed, academics face <a href="http://www.theguardian.com/higher-education-network/2014/mar/06/mental-health-academics-growing-problem-pressure-university">big challenges around mental health</a>. An attempt to raise productivity by sustained long hours is a Faustian bargain that can <a href="http://www.news.com.au/finance/work/the-country-working-itself-to-death/story-fnkgbb6w-1227252245840">ultimately take its toll</a> on you and those around you.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/88259/original/image-20150713-11795-1ovxp5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/88259/original/image-20150713-11795-1ovxp5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/88259/original/image-20150713-11795-1ovxp5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88259/original/image-20150713-11795-1ovxp5i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88259/original/image-20150713-11795-1ovxp5i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88259/original/image-20150713-11795-1ovxp5i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88259/original/image-20150713-11795-1ovxp5i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88259/original/image-20150713-11795-1ovxp5i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Balancing gender stereotypes about caregiving at home can make science an even more difficult place for women to advance.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/noaa_glerl/4075913150">NOAA Great Lakes Environmental Research Laboratory</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Science has <a href="http://www.theaustralian.com.au/higher-education/science-needs-more-women/story-e6frgcjx-1226614896100">a problem with women</a>. While the fraction of female students in undergraduate science classes <a href="http://www.nytimes.com/2011/11/06/education/edlife/where-the-women-are-biology.html">can sometimes be quite large</a>, the numbers drop off sharply at each higher rung of the career ladder. This <a href="http://www.newrepublic.com/article/119363/why-there-arent-more-top-female-scientists-leaky-pipeline">“leaky pipeline”</a> already has many causes, without easy solutions. The reality is that parenting and caregiving roles are not evenly split by gender, <a href="http://physicistfeminist.com/2012/08/25/study-finds-male-scientists-giving-wives-disproportionate-share-of-family-duties/">even more so for scientists</a>. Thus, if the scientific community follows <a href="http://www.sciencemag.org/content/349/6244/206.full">the advice on working hours and parenting</a> offered by my Toronto colleague, we are then even further fostering a culture that <a href="http://www.washingtonpost.com/wp-dyn/content/article/2006/09/03/AR2006090300773.html">directly holds back talented women</a> from successful scientific careers. And that limits <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0079147">the quality and breadth of ideas and discoveries</a>. </p>
<p>Instead, the senior figures in science should be putting their energy into <a href="http://sciencecareers.sciencemag.org/career_magazine/previous_issues/articles/2012_10_12/caredit.a1200115">flexible career tracks</a>, better <a href="https://aapm.utoronto.ca/part-time-academic-staff">part-time opportunities</a> and <a href="http://astronomy.swin.edu.au/wam/ASA_WiA2011/WiA2011_NaomiMcClureGriffiths.pdf">extra support for those returning to the lab after parental leave</a>. Scientists of any gender, whether parents or not, should be able to make choices around their investments in career and family, rather than be forced to compete with or accommodate outdated workaholic male stereotypes. </p>
<p>Those of us who are fortunate enough to have risen to senior academic positions have the privilege and responsibility of serving as mentors and role models to our junior colleagues. As young scientists learn the skills and approaches needed to become the science leaders of the future, they are deeply influenced by the advice of their lab heads and department chairs. So when someone asks me how many hours they should be working, I refuse to give them a number. Instead I tell them that they need to make sure they eat, sleep and relax, and that they should make time for their friends and families. Within those constraints, they need to figure out their optimal working hours for themselves.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/88261/original/image-20150713-11795-56aaai.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/88261/original/image-20150713-11795-56aaai.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/88261/original/image-20150713-11795-56aaai.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88261/original/image-20150713-11795-56aaai.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88261/original/image-20150713-11795-56aaai.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88261/original/image-20150713-11795-56aaai.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88261/original/image-20150713-11795-56aaai.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88261/original/image-20150713-11795-56aaai.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">Scientists are smart and creative – it’s time to use those talents to create better workplace expectations.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/iavi_flickr/9317042700">AIDSVaccine</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Science demands a lot of its disciples, so scientists should take control, not be controlled. Young researchers should determine how, where and when they work best, should set themselves rules, and then should try to stick to them. Ever since my time as a postdoc at MIT, I aim to walk out the door by 5 or 6 every night, I try not to answer emails on weekends and I take my allotted vacation time. Just as heads and directors are expected to be exemplars in our research, we must lead by example in work–life balance.</p><img src="https://counter.theconversation.com/content/44555/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Bryan Gaensler receives funding from the Natural Sciences and Engineering Research Council of Canada.</span></em></p>Despite macho career advice, it’s time for scientists – and everyone else – to understand that the point is to work smarter, not longer and to strive for a realistic and livable work/life balance.Bryan Gaensler, Director, Dunlap Institute for Astronomy and Astrophysics , University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/429852015-06-30T10:16:25Z2015-06-30T10:16:25ZI’m stuck like glue: why I love magnets and you should too<figure><img src="https://images.theconversation.com/files/86641/original/image-20150628-1431-ac980z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The invisible force and visible effects of magnetism.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/archeon/12857404305"> Hans Splinter</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>I have a confession: I’m obsessed with magnets.</p>
<p>We rely on magnets every day, but seldom give them a second thought. There are magnets in your credit card, your cellphone, your car, microwave oven and computer – and perhaps also pasted all over your refrigerator. </p>
<p>Probably the last time you thought about a magnet was in <a href="https://www.nde-ed.org/EducationResources/HighSchool/Magnetism/twoends.htm">a high school science class</a>. But you should realize they’re the unsung heroes of our world. Someone needs to stand up for magnets, and that person is me.</p>
<p>Don’t get me wrong. I’m not a magnet stalker or a magnet groupie. I’m a scientist, and I study magnetism for a living.</p>
<h2>Universally magnetic</h2>
<p>My main interest is in “<a href="https://www.skatelescope.org/magnetism/">cosmic magnetism</a>” – magnets in outer space. </p>
<p>Incredibly, magnetism is everywhere in the cosmos: planets, stars, gaseous nebulae, entire galaxies and the overall universe are all magnetic. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/86775/original/image-20150629-9054-170w15l.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/86775/original/image-20150629-9054-170w15l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86775/original/image-20150629-9054-170w15l.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=563&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86775/original/image-20150629-9054-170w15l.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=563&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86775/original/image-20150629-9054-170w15l.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=563&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86775/original/image-20150629-9054-170w15l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=707&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86775/original/image-20150629-9054-170w15l.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=707&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86775/original/image-20150629-9054-170w15l.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=707&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Our planet is one big magnet.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Earths_Magnetic_Field_Confusion.svg">TStein</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>What does it mean to say that a heavenly body is magnetic? For a solid body like the Earth, the idea is reasonably simple: <a href="http://www.geomag.nrcan.gc.ca/mag_fld/fld-eng.php">the Earth’s core is a giant bar magnet</a>, with north and south poles.</p>
<p>But farther afield, things get weird.</p>
<p><a href="http://phenomena.nationalgeographic.com/2014/12/08/magnetic-milky-way/">Our entire Milky Way galaxy is also a magnet</a>. Just like for the Earth, the Milky Way’s magnetism is produced by electrical currents. But while the Earth has a molten core to carry these currents, our galaxy’s magnetism is powered by uncounted numbers of electrons, slowly drifting in formation through space. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/86774/original/image-20150629-9102-wyi1lf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/86774/original/image-20150629-9102-wyi1lf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86774/original/image-20150629-9102-wyi1lf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86774/original/image-20150629-9102-wyi1lf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86774/original/image-20150629-9102-wyi1lf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86774/original/image-20150629-9102-wyi1lf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86774/original/image-20150629-9102-wyi1lf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86774/original/image-20150629-9102-wyi1lf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&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 magnetic field of our Milky Way galaxy as seen by the Planck satellite. Darker regions correspond to stronger polarized emission, and the striations indicate the direction of the magnetic field projected on the plane of the sky.</span>
<span class="attribution"><a class="source" href="http://www.mpa-garching.mpg.de/mpa/institute/news_archives/news1502_aaa/fig3.jpg">ESA and the Planck Collaboration</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The result is a magnet like nothing you’ve ever seen. </p>
<p>First, the Milky Way’s magnetism is unimaginably weak, around a million times weaker than the Earth’s. What’s more, instead of having a single north–south pole, there is seemingly <a href="http://www.mpifr-bonn.mpg.de/research/fundamental/cosmag">a separate magnet in each spiral arm</a> of our galaxy’s glowing pinwheel: different galactic neighborhoods have their own local definitions of north and south.</p>
<h2>Cosmic questions about cosmic magnets</h2>
<p>My own research has two focuses. First, what do galactic magnets look like? Where are all the north and south poles in our Milky Way, and in the millions of other galaxies scattered throughout the universe?</p>
<p>Second, and more importantly, where did all these magnets come from? How did the first cosmic magnets come into existence billions of years ago, and how have they survived through to the present day?</p>
<p>These questions are not quite as esoteric as they sound. </p>
<p>Magnetism is vital for <a href="https://www.cfa.harvard.edu/news/2009-20">stars like our sun to form</a>. The Earth’s magnetism <a href="http://www.esa.int/Our_Activities/Space_Science/Cluster/Earth_s_magnetic_field_provides_vital_protection">protects our atmosphere from harmful radiation</a>. And cosmic magnets generate energetic high-speed particles which, on arrival at Earth, <a href="http://www.space.com/7193-death-rays-space-bad.html">can cause random genetic mutations</a> and hence drive evolution.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/DRR3IPfTXiE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Faraday rotation is an effect through which light is rotated as it passes through magnetized regions of space. (Swinburne Astronomy Productions / CAASTRO: The ARC Centre of Excellence for All-sky Astrophysics)</span></figcaption>
</figure>
<p>On the other hand, the answers are elusive. The big challenge is that magnetism is invisible: point a powerful telescope at a cosmic magnet, and you won’t see it. Instead, we use indirect approaches, relying on the fact that <a href="http://dunlap.utoronto.ca/%7Ebgaensler/papers/stories/301Gaensler-3.pdf">background light is subtly changed</a> as it passes through magnetic regions of foreground gas. I think of it as trying to do the ultimate cryptic crossword puzzle, but blindfolded and with your hands tied behind your back. </p>
<h2>A magnetic sixth sense</h2>
<p>Of course, one can’t spend one’s whole life just thinking about cosmic magnets. Every scientist has a secret unfulfilled ambition: a completely different scientific career that perhaps, if things had been different, they would have pursued instead.</p>
<p>So what’s my secret alternative vocation? </p>
<p>In a parallel universe, I would still be obsessed with magnets. But I would not be an astronomer. Instead I would study “magnetoreception.” </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/86643/original/image-20150628-1438-3k8odr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/86643/original/image-20150628-1438-3k8odr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86643/original/image-20150628-1438-3k8odr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86643/original/image-20150628-1438-3k8odr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86643/original/image-20150628-1438-3k8odr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86643/original/image-20150628-1438-3k8odr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86643/original/image-20150628-1438-3k8odr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86643/original/image-20150628-1438-3k8odr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Birds’ long migrations can be tied to their magnetic ‘sixth sense.’</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/wolfraven/3108329398">Jack Wolf</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Magnetoreception is the ability of some animals to <a href="http://www.the-scientist.com/?articles.view/articleNo/36722/title/A-Sense-of-Mystery/">respond or react to magnetism</a>: a “sixth sense” that allows them to see the unseen. The best-known examples are birds, some species of which <a href="http://www.nytimes.com/2012/04/27/science/study-sheds-light-on-how-pigeons-navigate-by-magnetic-field.html">navigate using the Earth’s magnetic field</a> during their spectacular globe-spanning migrations. </p>
<p>But in recent years, scientists have found that a whole host of other species can sense magnetism. Perhaps the most extraordinary case is that of <a href="http://www.nature.com/news/the-mystery-of-the-magnetic-cows-1.9350">magnetic cows</a>. Using images from Google Earth, researchers have claimed that cows around the world tend to align their bodies with the Earth’s magnetic field whenever they are grazing or resting.</p>
<p>Other studies, covering everything from <a href="http://www.smithsonianmag.com/smart-news/earths-magnetic-field-draws-sea-turtles-their-nests-180953926/?no-ist">the swimming patterns of sea turtles</a> to the <a href="http://www.pbs.org/newshour/rundown/dogs-poop-in-alignment-with-earths-magnetic-field-study-finds/">directions dogs face when they defecate</a>, have similarly revealed that animals can somehow sense magnetism. </p>
<p>Even humans might have some vestigial sensitivity to magnets. <a href="http://www.ncbi.nlm.nih.gov/pubmed/11976892">Vision quality seems to depend</a> on whether you’re facing north–south or east–west. Dreams are more likely to be <a href="http://www.newscientist.com/article/dn16871-sweet-dreams-are-made-of-geomagnetic-activity.html">mundane rather than bizarre</a> when the Earth’s magnetism is going through a period of high activity. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/86645/original/image-20150628-1428-liw6y9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/86645/original/image-20150628-1428-liw6y9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86645/original/image-20150628-1428-liw6y9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=307&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86645/original/image-20150628-1428-liw6y9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=307&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86645/original/image-20150628-1428-liw6y9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=307&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86645/original/image-20150628-1428-liw6y9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=386&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86645/original/image-20150628-1428-liw6y9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=386&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86645/original/image-20150628-1428-liw6y9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=386&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 pluses of magnets.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Bar_magnet.jpg">Aney</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Well-known but so mysterious</h2>
<p>It’s now been around 2,600 years since <a href="http://galileoandeinstein.physics.virginia.edu/more_stuff/E&M_Hist.html">the Greek philosopher Thales noticed that magnets attract iron</a>. We understand almost completely how magnets work, right down to <a href="http://magician.ucsd.edu/essentials/WebBookse16.html">the detailed atomic level</a>. Once a curiosity, magnetism is now at our beck and call, and <a href="http://www.northeastern.edu/sunlab/mom/technology.html">underpins our entire modern world</a> of convenience and technology. </p>
<p>We might have completely tamed magnets for our purposes, so much so that we almost never give them a moment’s thought. But both up in the heavens and down here on the ground, there’s still a huge amount we don’t understand about magnets. Where did magnets come from? How have they shaped the universe? And what roles do they play for life on Earth? </p>
<p>So please don’t overlook magnets. Magnets are marvelous, mysterious and magical, and deserve both your affection and your respect.</p><img src="https://counter.theconversation.com/content/42985/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Bryan Gaensler receives funding from the Natural Sciences and Engineering Research Council of Canada.</span></em></p>I have a confession: I’m obsessed with magnets. We rely on magnets every day, but seldom give them a second thought. There are magnets in your credit card, your cellphone, your car, microwave oven and…Bryan Gaensler, Director, Dunlap Institute for Astronomy and Astrophysics , University of TorontoLicensed as Creative Commons – attribution, no derivatives.