By Dr Alastair Gunn

Published: Friday, 15 October 2021 at 12:00 am


There are at least 277 pieces of Martian rock that have been found on Earth. But, so far, only one possible piece of Earth has been found in space. Inside a lunar sample returned by the Apollo 14 astronauts, scientists found a 2g fragment of quartz, feldspar, and zircon. These are all common minerals on Earth but highly unusual on the Moon.

It’s possible that the rock formed on Earth about four billion years ago and was launched into space by an impacting asteroid or comet. But we can’t be sure – recent research suggests the rock may have a lunar origin after all!

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The lunar sample ‘Big Bertha’ contains a fragment that may have Earth origins © NASA

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Asked by: James Edgell, Oxford

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