Why is that odd? Iapetus has no atmosphere and only 1/44th the gravity that Earth had.
We’ve been learning a lot about Iapetus, since the Cassini mission made an amazing pass in 2007. We have amazing photos, too. But avalanches are a new bird for this moon.
(Fun fact: It’s fitting that the Cassini probe passed Iapetus, since the moon was discovered by its namesake, astronomer Giovanni Domenico Cassini, in 1671.)
Scientist Kelsi Singer observed that, after studying images of Iapetus, there are massive ice avalanches taking place that occur in a strikingly similar way to the ones on Earth.
“The landslides on Iapetus are a planet-scale experiment that we cannot do in a laboratory or observe on Earth,” Singer said in a report. “They give us examples of giant landslides in ice, instead of rock, with a different gravity, and no atmosphere. So any theory of long runout landslides on Earth must also work for avalanches on Iapetus.”
Some avalanches have been found to be up 50 miles wide.
This level of attention is new for Iapetus. It’s one of 62 Saturnian moons, but avalanches are something unique, calling attention to the tiny ball of ice.