Saturn’s moon Iapetus certainly isn’t one of the more common celestial bodies for most of us, but the moon is very interesting. One of the most interesting things about the moon is that it has a ridge of mountains around its equator giving it the look of a plastic ball or walnut. Planetary scientist Kelsi Singer was studying images of the icy moon and found something very interesting and unexpected, massive ice avalanches.
Half of Iapetus is always in the sunlight, and half of the moon surface is always in the dark. The mountains on the surface of the icy moon are 12 miles high, twice as tall as Mount Everest. While the surface of the moon is peculiar indeed, Singer says that the ice avalanches were something that the team never expected to discover. Singer discovered the massive ice avalanches on the surface of the moon while studying images of the moon’s surface.
According to the scientists, the icy landslides are similar to landslides that happen on earth known as sturtzstorms. This sort of landslide can travel a distance across the surface of the earth equal to 20 to 30 times the height it fell from. Singer believes that the landslides on the surface of Saturn’s icy moon were likely triggered by objects hitting the moon’s surface.
The scientists don’t agree at this point on what mechanism might allow this type of landslide to travel so far on earth. There are several hypotheses including that the landslide may ride on a cushion of trapped air, slide on ground water or mud under the surface, slide on ice, or the cause could be strong acoustic vibrations. Singer believes that on the surface of Iapetus, which has no atmosphere and no groundwater, the landslides occurred by the frictional heating of the ice. Singer and her team believe that the reduced friction that allowed the landslides on Saturn’s moon to be so long compared to the height they fell from is “flash heating” of the ice until it was slippery enough to allow sliding without melting.