Seventeen tiny particles recovered from a flat-topped mountain in eastern Antarctica suggest that a space rock shattered low in the atmosphere over the ice-smothered continent about 430,000 years ago.
The nickel- and magnesium-rich bits were sifted from more than 6 kilograms of loose sediments collected atop the 2,500-meter-tall summit of Walnumfjellet, says Matthias van Ginneken, a cosmochemist at the University of Kent in England. Their exotic chemistry doesn’t match Earth rocks, but it does match the proportions of elements seen in a type of meteorite called a carbonaceous chondrite, van Ginneken and his colleagues report March 31 in Science Advances.
Most of the particles range in size from 0.1
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