Figure 10-19: The Rate of Crater Formation on the Moon This graph shows the rate at which impact craters formed over the Moon’s history. The impact rate today is only about 1/10,000 as great as during the most intense bombardment.

(Adapted from T. Grotzinger, T. H. Jordan, F. Press, and R. Siever, Understanding Earth, 5th ed., W. H. Freeman, 2007)