Articles on Astrophysics

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Ripples in a pond help to illustrate wave motion and the Doppler effect. *˜Dawn˜*

Explainer: the Doppler effect

When an ambulance passes with its siren blaring, you hear the pitch of the siren change: as it approaches, the siren’s pitch sounds higher than when it is moving away from you. This change is a common…
There’s far more to the night sky than the human eye can see. Joseph Dsilva

Explainer: radio astronomy

Humans have always had a deep affinity with the night sky. Over millennia the stars have guided us in our travels, provided a grand canvas for the great stories of mythology and invoked a sense of wonder…
A simulated Black Hole of ten solar masses as seen from a distance of 600km with the Milky Way in the background. Ute Kraus/Wikimedia

Explainer: black holes

The concept of a “black hole” is one of the most curious in astrophysics. It’s the answer to the question: “What happens if the density of matter in a region becomes so high that not even light can escape…
Don’t look at the transit of Venus directly … but make sure you look at it. Jan Herold

Transit of Venus: a must-see for everyone … no seriously

When Australia II won the America’s Cup yacht race in 1983, then-prime-minister Bob Hawke famously exclaimed: “Any boss who sacks anyone for not turning up today is a bum.” Taking inspiration from this…
Everyone’s getting a slice of the SKA, whichever way you cut it. swishphotos

Science vs politics in the SKA decision: the winner was …

Late last week, the Square Kilometre Array (SKA) board chairman, John Womersley, announced that the future telescope will have more than one home: Australia/New Zealand and South Africa. The announcement…
The global push to detect gravitational waves could provide an enormous return for science. Wikimedia Commons

Rippling space-time: how to catch Einstein’s gravitational waves

Albert Einstein made an executive decision to revolutionise our understanding of gravity in a paper published in 1916. Nearly 100 years on, a key prediction of Einstein’s theory has eluded direct detection…
Trojans such as (1173) Anchises appear to have been caught in Jupiter’s orbit, mid-flight. Dave Hosford

By Jupiter: the gas giant’s Trojans were captured, not pre-formed

You’ll remember that, about a year ago, Canadian astronomers announced the discovery of a small asteroid sharing the earth’s orbit. The asteroid in question, 2010 TK7, is a “planetary Trojan” – an object…
Knowing where cosmic rays don’t come from brings scientists another step closer to determining their origin. NSF/J. Yang

An extragalactic mystery: where do high-energy cosmic rays come from?

It’s been the defining question of high-energy astrophysics for the past century: where do cosmic rays come from? New findings from the IceCube Neutrino Observatory at the South Pole have brought us closer…
The Big Bang theory and the existence of God are ideas often grappled with when thinking about how the universe was created. DamienHR

The origin of the universe: is there a role for God?

Last week’s Global Atheist Convention and debates between prominent atheists and theologians in the Australian media has seen arguments about the existence of God getting a thorough airing. In my view…
It’s time we got to the core of our planet’s early history. Derringdos

What on Earth! Hot news on our planet’s formation

As of today, the world might have changed forever. A fundamental assumption underpinning much of modern geochemistry is that the earth has the same composition as a class of meteorites called chondrites…

Repellant dark matter confounds astronomers

In a result which has baffled astronomers at NASA’s Chandra X-ray Observatory, dark matter has been observed separating from…
The James Webb Space Telescope will search for stars in the dawning universe. BOBXNC

Hubble, Webb and the search for First Light galaxies

When the Obama administration announced its proposed NASA budget in February, astronomers worldwide breathed a sigh of relief. Despite significant cuts in other areas, funding for the James Webb Space…

Dark matter core challenges theories

The collision of several, massive galaxy clusters has left behind a clump of dark matter, potentially challenging existing…
All good things must come to an end. Michael Ashley

The Antarctica Diaries: the final instalment

Professor Michael Ashley recently returned from Antarctica where he deployed a telescope to one of the most remote locations on Earth – a place known as Ridge A, 850km from the South Pole. This is the…

X-rays reveal inside of the moon

X-rays of the moon have shown that, unlike Earth, our rocky satellite has no active volcanos, and hasn’t for billions of…
GRBs have puzzled astronomers for decades, and there is still plenty to learn. EOS/A Roquette

Flash, aah-aah! Could a gamma ray burst eradicate all life on Earth?

Ever since they were discovered accidentally in the 1960s, gamma ray bursts (GRBs) have continued to amaze and puzzle astronomers worldwide. In nearly 50 years of research there seem to have been more…

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