The Late Heavy Bombardment is a hypothesised period in the early history of the inner Solar System when the Moon, Earth and the other rocky planets were struck by an unusually large number of asteroids and comets. The idea arose from radiometric dating of lunar samples returned by the Apollo missions, which suggested that many of the large impact basins on the Moon formed around the same time. One explanation links it to a rearrangement of the giant planets' orbits, which would have disturbed the asteroid belt. Other scientists argue that the evidence reflects a sampling bias or the tail end of the planets' formation rather than a distinct spike. If real, it would have affected the conditions in which life on Earth first emerged.
Before and after
- from about 4.1 billion years ago to 3.8 billion years agoLate Heavy Bombardment
- from about 3.92 billion years ago to 3.85 billion years agoNectarian
- from about 2.4 billion years ago to 2.1 billion years agoHuronian glaciation
- from about 1.8 billion years ago to 800 million years agoBoring Billion
- about 543 million years agoCambrian explosion
- about 444 million years agoOrdovician–Silurian extinction event
- from about 380 million years ago to 280 million years agoVariscan orogeny
- about 375 million years agoFish with limbs begin to walk: tetrapods evolve
- about 372 million years agoLate Devonian extinction
More in Earth & climate
- 79 CEVesuvius buries Pompeii and Herculaneum
- from 1303 to 1850Little Ice Age
- from October 1347 to January 1351The Black Death reaches Europe
- 1938Establishment of Mount Olympus
- 2001Establishment of Phong Nha–Ke Bang National Park
- 11 March 2020The WHO declares COVID-19 a pandemic
The era
This moment belongs to the Hadean (4.54 billion years ago to 4.03 billion years ago), the molten birth of Earth.