Post by glactus on Mar 22, 2008 4:13:54 GMT
A study of meteorites suggests that Mars, the Earth and the Moon share a common composition from ‘growing up’ in a unique planetary nursery in the inner solar system.
The finding could lead to a rethink of how the inner solar system formed.
In the journal Nature the international team of scientists, which includes Professor Alex Halliday from Oxford University’s Department of Earth Sciences, report how they analysed 16 meteorites that fell to Earth from Mars.
They found that the amounts of neodymium-142 these contain are subtly different from those of objects found in the asteroid belt. This isotopic fingerprint is proof that the chemistry of the inner solar system was different even for elements that are hard to vapourise.
Professor Halliday said: ‘The Earth, Moon and Mars appear to have formed in a part of the inner solar system with a ratio of samarium to neodymium that is around 5 per cent more than could be found in the asteroid belt.
"What we can say is that the composition of these worlds is inconsistent with them simply forming out of large ‘lumps’ of stony meteorites, like those we see today in the asteroid belt."
THe Planets
credits:
This article has been adapted from materials provided by the University of Oxford.
This is part text only. See image, full text and all scientists involved at sciencedaily.com
www.sciencedaily.com/releases/2008/03/080319140319.htm