Earth and Moon impact flux increased at the end of the Paleozoic

Abstract

Impact rates on Earth and the Moon The rate at which impacts produce craters on the Moon is used to calibrate ages in planetary science. Earth should also have received similar numbers of impacts, but many craters have been hidden by erosion, ice sheets, and so on. Mazrouei et al. used infrared images of the Moon to estimate the ages of young lunar craters (see the Perspective by Koeberl). They found that the impact rate increased within the past ∼500 million years, a conclusion strengthened by an analysis of known impact craters on Earth. Crater size distributions are the same on Earth and the Moon over this period, implying that terrestrial erosion affects all craters equally, regardless of their size. Science , this issue p. 253 ; see also p. 224