Recently astrophysicists at Cambridge and Warwick have discovered a rocky, yet water rich asteroid orbiting a white dwarf (GD 61 to be specific) about 170 light years from our solar system. But this was no ordinary rock.The rocky body was found using images from the Hubble and the Keck telescope on Hawaii, but through reanalyzing the images a rich presence of oxygen was discovered. Exactly how is put better by the scientists themselves: “The Hubble and Keck data allows the researchers to identify the different chemical elements that are polluting the outer layers white dwarf. Using a sophisticated computer model of the white dwarf atmosphere, developed by Detlev Koester from the University of Kiel, they can then infer the chemical composition of the shredded minor planet” (Boris Gaensicke). This lead scientist to conclude that the rocky body had once been a part of a larger planet comprised of at least 26% water by mass. Compared to the Earth’s only .023%, that’s a lot of water! So why is this presumably life-less rock important to us. We have previously discovered water out side of our solar system, but this is the first time it has not been in the atmosphere of a large gas giant.
An Artists Depiction of the Asteroid
The planet was likely destroyed around 200 million years ago by gravitation force when GD 61 went from being a star slightly larger than our sun to a white dwarf and when the a yet to be seen larger planet knocked the smaller one out of its normal orbit. Physicists have compared the previous planet to one called Ceres that is thought to be one of the largest contributors to water here on Earth. The destroyed planet also probably had ice below the surface like Ceres. Hopefully this new knowledge can tell us more about the formation of our solar system and the necessities required for life.
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Photo: (Crdt. Mark A. Garlick, space-art.co.uk, University of Warwick and University of Cambridge)
http://www.eurekalert.org/pub_releases/2013-10/uow-wdi100313.php
