Until we started sending missions to the Moon, the concept of the lunar surface was one of jagged mountains and steep-walled canyons. That concept was molded mainly by the amazing artwork of Chesley Bonestell, which was featured in magazines and movies.

The reality is much different. The mountains and canyons are smooth and rounded — the result of billions of years of pounding by space rocks. Most of the rocks that hit the Moon are tiny — the size of pebbles or smaller. They slowly erode the mountains and churn the surface into a powdery soil.

But a few impacts are bigger — big enough to gouge visible impact craters.

A recent study looked at how often those larger impacts take place. Scientists compared pictures taken 42 years apart — the first by Apollo 15, the second by Lunar Reconnaissance Orbiter. The images covered about 10 square miles, near the Apollo 15 landing site.

The comparison showed about 320 new craters. The largest was 50 feet across. Some of the craters could be secondary — formed when the debris from a collision splashed out around the impact site. Even so, the study shows that the surface of the Moon continues to be resculpted — beaten into shape by a rain of space rocks.

The Moon has a prominent companion late tonight: Aldebaran, the bright orange heart of Taurus, the bull. The star is close to the lower right of the Moon as they climb into good view, by about 11 o’clock.
 

Script by Damond Benningfield