Crater counting
From Wikipedia, the free encyclopedia
Crater counting refers to a method for estimating the age of a planet's surface. The method is based upon the hypothesis that a new surface forms with zero impact craters, and that impact craters accumulate at some known rate. The method has been calibrated using the ages of samples returned from the Moon.
[edit] Crater counting on Mars
The accuracy of age estimates based on crater counting on Mars has been questioned due to formation of large amounts of secondary craters. In one case, the impact that created Zunil crater produced about a hundred million of secondary craters, some more than 1000 km from the primary impact. If similar impacts also produced comparable amounts of secondaries, it would mean a particular crater-free area of Mars had not been "splattered by a large, infrequent primary crater", as opposed to suffering relatively few small primary impacts since its formation. [1][2]
[edit] References
- ^ Chandler, D (2005-03-28). Crater count led Mars historians astray. New Scientist. Retrieved on 2008-06-07.
- ^ Kerr, R (2006). "Who can Read the Martian Clock?". Science 312: 1132 - 1133. doi:.
