Twice each semester, I lecture about mass wasting, the class of processes that includes rockfalls, landslides, avalanches, and mudslides, in my geology classes. The important point I make about mass wasting is that it doesn't need an agent of erosion, such as moving water, ice, or air, to move material. The only conditions it requires are loose material on a sloping surface and gravity. That means it could happen on the Moon, Mars, or an asteroid, and scientists have observed evidence of mass wasting on all these bodies. I illustrate the point with the above image showing an avalanche on Mars. Now I have a video about mass wasting on an asteroid to show my students. Even better, it's the old friend of the blog Apophis.
Watch as Discovery News asks Should We Worry About An Avalanche On An Asteroid?
In 2029, a football field-sized asteroid is going to fly so close to Earth that it's going to trigger a series of massive avalanches. Amy explains why we Earthlings have nothing to worry about.In it's own way, this news is even more reassuring than Apophis Day postponed until 2068.