The
Late Heavy Bombardment (abbreviated
LHB and also known as the
lunar cataclysm) is an event thought to have occurred approximately 4.1 to 3.8 billion years (
Ga) ago, corresponding to the
Neohadean and
Eoarchean eras on Earth. During this interval, a disproportionately large number of asteroids apparently collided with the early
terrestrial planets in the inner Solar System, including
Mercury,
Venus,
Earth, and
Mars. The LHB happened after the Earth and other rocky planets had formed and
accreted most of their mass, but still quite early in Earth's history.