Impact craters, from tiny pits to giant basins, are the dominant landforms of the Moon. Just a handful of the largest craters appear nearly unchanged since they formed over a billion years ago. The rest have been reshaped by subsequent events. In fact, modification was common in the first half-billion years of lunar history. Craters large and small were completely destroyed or otherwise altered by other impacts in the earliest lunar epoch. However, between about 3.8 and 1 billion years ago, this degradation slowed as the impact rate rapidly declined. In the last billion years, the mixing of crater rays and mare soils has become the dominant modification process (S&T: July 2019, p. 52).
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