What was the Late Heavy Bombardment?
The late heavy bombardment is a period of highly intensified asteroid impacts taking place between 3920 and 3850 million years ago (mya). Life itself was formed either a few dozen million years before the late heavy bombardment or near its conclusion. Evidence for the late heavy bombardment was found by Apollo astronauts visiting the Moon. Out of all the rock samples they brought back, many of them clearly remelted after asteroid impacts, and these remelting events were clustered with ages 3920 million years or a hundred or so million years younger. This period of time thereafter became called the “lunar cataclysm.” Asteroids from the Moon have been shown all to have the 3920 million year age limit, but they are not clustered around the short time thereafter, having ages ranging from 2500 to 3900 mya. By extension, it was inferred that Earth, Venus, and Mercury would have also experienced a substantial increase in asteroid impacts during this period. If the late heavy bombardment reall
