Moon, Asteroid Hit By Asteroid Collision Storm Lasting Millions Of Years

Both the earth’s moon and the large asteroid Vesta were victims of a widespread cataclysm caused by multiple high-speed smaller asteroids that rained down on them for hundreds of millions of years. Considering that Vesta is very distant from the earth, the evidence suggested that the bombardments must have affected all of the planets and large asteroids in the inner solar system — including the Earth itself. That’s the result of an analysis of rocks from both the moon and Vesta that were analyzed by NASA’s Lunar Science Institute (NLSI) and published earlier this week in Nature Geoscience.

Fortunately for us, the event occurred around four billion years ago. However, the news is still a tad disquieting in the wake of the well-publicized Russian meteor that injured 1,200 people in February and the multiple near-misses of earth by four asteroids that passed our planet in just one week in early March.

According to the Jet Propulsion Laboratory, the new discovery supported a theory that when the enormous gas giants Jupiter and Saturn repositioned in the early solar system, their massive gravitational pull upset the orbits of many small, rocky asteroids. Knocked out of their proper path, the surprisingly numerous asteroids became attracted by gravity to other bodies.

The result? A hailstorm of out-of-control asteroids raining down on the moon, larger asteroids like Vesta, and planets like our Earth and Mars.

That event is called the lunar cataclysm because it was first discovered on our airless satellite. On Earth, the work of four billion years’ worth of wind, water, and plant growth easily obscured the evidence.

The rain of stone from the sky wasn’t pleasant. In February, NLSI released their re-creations of what happened when two larger asteroids collided with Vesta. One of the resulting craters is still one of the largest craters known in the solar system — over 300 miles long. An impact crater of that magnitude on earth might be a life-ending event.

The Chicxulub crater in Mexico, the site of the impact that wiped out the dinosaurs 65 million years ago, is only 110 miles in diameter.

It’s fun to imagine the moon and Vesta, not to mention all their friends, being rained on by asteroids. It’s even more fun to imagine it happening a safe four billion years in the distant past.

[Image credit: NASA/GSFC/ASU/JPL-Caltech/UCLA/MPS/DLR/IDA]