Varying crater rate on the Earth’s Moon

Varying crater rate on the Earth’s Moon

Fig. 2.18 . The rate of forming craters on the lunar surface is plotted against time. The circles denote the crater rate and rock ages at various Apollo landing sites. The crater rate was very high during an intense bombardment that occurred 3.9 billion years ago. The rate dropped rapidly during the subsequent billion years, giving way to the lower steady rate of crater production that has persisted for the last 3 billion years. With such a curve, we can obtain approximate surface ages just by counting the number of craters in different parts of the Moon. Estimates of the ages of planetary surfaces can similarly be obtained from the density of craters on them.

Copyright 2010, Professor Kenneth R. Lang, Tufts University