Saturn’s moon Iapetus may hold secrets behind unusual landslides

BBC : Whereas normal landslides usually travel twice as far horizontally as they fall vertically, so-called long-runout landslides can travel a horizontal distance that is up to 30 times their vertical fall. These unusual landslides, which have been observed on both Earth and Mars, have now been found elsewhere in the solar system: on Saturn’s icy moon Iapetus, which is covered with mountains and craters of extreme size. New images taken by NASA’s Cassini probe suggest that the ice debris in the landslides may melt due to the heat and pressure of the other material in the slides. The increased fluidity of the material would greatly decrease the coefficient of friction and allow the landslides to travel a much greater horizontal distance, much like skaters whose skate blades create a thin layer of water that allows them to glide across a frozen surface. Although several competing theories seek to explain the long-runout landslides, existing observations lack the detail to provide a definitive test.