Astronomers say they have determined a single gigantic meteoroid erased most small craters from 40 percent of the surface of asteroid Eros.
Writing in this week's issue of Nature, researchers Peter Thomas of Cornell University and Mark Robinson of Northwestern University said they used data gathered in 2000-01 from the NEAR-Shoemaker spacecraft, which mapped the 20-mile-long asteroid in detail.
They argue that vibrations from the collision shook the asteroid enough to collapse smaller craters. And that, they said, suggests Eros has a relatively homogeneous interior that transmits seismic shocks efficiently.
"This asteroidal Botox calls into question the habit of dating asteroid surfaces through their cratering record," wrote Erik Asphaug, a planetary scientist at the University of California-Santa Cruz, in a related article.
Copyright 2005 by United Press International
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