spacetoday.net: Earth's gravity can alter passing asteroids

Earth's gravity can alter passing asteroids

Posted: Thu, Jan 21, 2010, 7:26 AM ET (1226 GMT)
Asteroid passing near Earth illustration (MIT)

The surfaces of asteroids that pass near the Earth can be shaken by the Earth's gravity, which may explain differences in color for these objects. In a paper in this week's issue of Nature, scientists said that when asteroids approach to within one-quarter the distance of the Moon, gravity can shake the surfaces of these bodies, uncovering fresh material. This process can explain why such Q-type asteroids are not seen in the main asteroid belt, where asteroids have redder surfaces caused by "space weathering" from interaction with the solar wind.