Impact craters reveal one of the most spectacular geologic process known to man. During the past 3.5 billion years, it is estimated that more than 80 bodies, larger than the dinosaur-killing asteroid that struck the Yucatan Peninsula 66 million years ago, have bombarded Earth. However, tectonic processes, weathering, and burial quickly obscure or destroy craters. For example, if Earth weren't so dynamic, its surface would be heavily cratered like the Moon or Mercury.
Fuente : http://www.alphagalileo.org/ViewItem.aspx?ItemId=1...
Fuente : http://www.alphagalileo.org/ViewItem.aspx?ItemId=1...