near-Earth asteroid(redirected from earth-grazer)
Also found in: Dictionary, Wikipedia.
near-Earth asteroid(NEA) Any asteroid that has a chance of hitting our planet, specifically any member of the Apollo, Amor, and Aten groups. Although the annual probability of the Earth being struck by a large asteroid or comet is extremely small, the consequences of such a collision are so catastrophic that it was thought prudent in the USA to assess the nature of the threat and to be prepared to deal with it.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006