The moon’s craters suggest Earth hasn’t erased lots of past impacts

Existing craters hint that asteroids increasingly pummeled both some 290 million years ago

lunar map

SCARRED SURFACE  The moon held on to almost all the craters it’s ever acquired in 4.5 billion years of impacts. This lunar map is surrounded by images of 111 craters wider than 10 kilometers and younger than a billion years.

Dr. A. Parker/SWRI

A new look at the moon’s craters suggests the Earth and moon both suffered a sharp increase in impacts around 290 million years ago, and Earth has kept its biggest scars.