Last Updated: Thursday, April 26, 2012, 19:13
Analysing tiny "spherules" embedded in layers of rock, a team from the Purdue University in the US said they found the "first real solid evidence" of asteroid bombardment.
Last Updated: Thursday, April 26, 2012, 12:52
The spherules were created when asteroids crashed into the Earth, vaporizing rock that expanded into space as a giant vapour plume.
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