The last great cosmic storm
Between roughly 4.1 and 3.8 billion years ago, the inner solar system was hit by a sudden surge of asteroids and comets. This period, called the Late Heavy Bombardment, left the Moon covered in the large craters we still see today and repeatedly hammered the young Earth.
Destruction and Delivery
The impacts were powerful enough to melt large parts of Earth’s surface. At the same time, many of the incoming bodies carried water and organic molecules. Some researchers believe this bombardment played a major role in delivering the water that would later fill Earth’s oceans.
By the end of this final storm, the solar system had largely settled into the configuration we know today. The worst of the chaos was over.
The Late Heavy Bombardment was both destroyer and deliverer. It repeatedly reset the surface of the young Earth, yet it may also have brought the water and organic building blocks that made life possible.
- Most of the Moon’s large impact basins were created during this relatively short period.
- The bombardment may have delivered a significant portion of Earth’s water.
- Similar spikes in impacts have been detected on Mars and across the asteroid belt.
- Some models suggest the Late Heavy Bombardment was triggered by the migration of Jupiter and Saturn.
- The period lasted only a few hundred million years but left a permanent mark on the inner solar system.
- After this final storm, truly large impacts became much rarer on Earth.
The final bombardment
A reconstruction of the intense period of impacts that cratered the Moon and battered the young Earth during the Late Heavy Bombardment.
Gallery
Late Heavy Bombardment Timeline
| Time | Event |
|---|---|
| ~4.1 billion years ago | Bombardment begins |
| ~3.9 billion years ago | Peak intensity |
| ~3.8 billion years ago | Bombardment declines |
| After 3.8 billion years ago | Archean stability |
Why the Late Heavy Bombardment Matters
This was the final major reset of the early solar system. It repeatedly reshaped the young Earth, yet it may also have delivered the water and organic building blocks that made life possible. After this storm, our planet finally entered a more stable era.