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3 weeks ago | 
australiangeographic.com.au | Fred Watson
Contributor Fred Watson Contributor Fred Watson Fred Watson is Australia’s Astronomer-at-Large.
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2 months ago | 
australiangeographic.com.au | Fred Watson
Contributor Fred Watson Contributor Fred Watson Fred Watson is Australia’s Astronomer-at-Large.
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Nov 10, 2024 | 
australiangeographic.com.au | Fred Watson |Australia's Astronomer
Back in the 1970s, a concentrated effort in the search for extraterrestrial intelligence (SETI) was well underway at the Big Ear radio telescope in Delaware, USA. More formally known as the Ohio State University Radio Observatory, this unusual telescope looked more like a sports arena than a conventional steerable dish. Nevertheless, between 1965 and 1971, it produced the most complete map of the radio sky yet attempted.
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Oct 13, 2024 | 
australiangeographic.com.au | Fred Watson |Australia's Astronomer-at-Large
Back in September 1969 in a laboratory in north-eastern England, a young, newly minted physics graduate was engaged in a job that no more than a dozen people worldwide would be doing. It was a humble task – fabricating a circular polyethylene air-bag 3.9m in diameter and no more than a couple of centimetres thick. What made the job unique was the purpose of this unwieldy plastic pouch.
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Sep 17, 2024 | 
australiangeographic.com.au | Fred Watson |Australia's Astronomer-at-Large
We know of only one other celestial body where long-lasting reservoirs of liquid pool on the surface, and it’s a very strange world indeed. Saturn’s moon Titan is the second largest in the solar system, eclipsed only by Jupiter’s Ganymede. Its surface is not rock, but ice that’s –180°C. This ice is underlain by a global ocean of liquid water that is, in turn, underlain by a rocky core. Enveloping Titan is an atmosphere that has curious parallels with our own, despite its frigid temperature.
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Aug 11, 2024 | 
australiangeographic.com.au | Fred Watson |Australia's Astronomer-at-Large
To understand why, we have to go back to 1967, when the first of a class of astronomical events known as gamma-ray bursts, or GRBs, was observed. Discovered serendipitously by satellites designed to detect gamma-ray flashes from illegal nuclear tests, the bursts were soon identified as coming from space. Moreover, when new spacecraft were introduced in the 1990s, they were found to originate deep in the universe, well beyond the confines of our Milky Way galaxy.
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Jun 24, 2024 | 
australiangeographic.com.au | Fred Watson |Australia's Astronomer-at-Large |Candice Marshall
So, what is an ocean world? Basically, it’s a ball of rock enveloped in water, which is in the form of ice unless it’s within the “habitable zone” of its parent star – in which case it becomes liquid water. Earth holds that privileged position in our solar system, but further out, ice predominates, with the subtle twist that internal heating from beneath the rocky surface can melt the lower levels of the ice mantle to create a sub-ice ocean.
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Apr 4, 2024 | 
australiangeographic.com.au | Fred Watson |Candice Marshall
Because of the finite speed of light and radiation, the further into space you look, the further back in time you’re seeing. Such is astronomers’ prowess with this cosmic capacity that they are able to see back to an era when the universe was still glowing brilliantly after its birth during the Big Bang. That glow is in the microwave spectrum and covers the whole sky, providing a background against which everything else is seen.
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Jan 8, 2024 | 
australiangeographic.com.au | Fred Watson |Australia's Astronomer-at-Large |Candice Marshall
Like chocolate bars, however, galaxies come in different shapes and sizes, and not all have a spiral structure. Some are featureless blobs shaped like rugby balls; others are ragtag objects, fittingly known as irregulars. But spirals constitute some 60 per cent of the universe’s estimated 2 trillion galaxies, so what you’ve pictured is fairly accurate. Astronomers think they understand why galaxies have spiral arms.
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Dec 11, 2023 | 
australiangeographic.com.au | Fred Watson |Australia’s Astronomer-at-Large
This is the Geminid shower, named after the constellation from which the meteors seem to come as they flash across the sky, vaporised by their rapid entry into our planet’s atmosphere. Their origin from a single point in the sky is just an illusion of perspective, because the meteors are actually moving on parallel tracks. What is more interesting is their true origin – where did the Geminid meteors come from? And that has been an enduring mystery for astronomers.
