A meteoroid smashed into the side of a crater on Mars and then started a landslide
(PHYSorg.com Space & Earth)

In 2006, NASA`s Mars Reconnaissance Orbiter (MRO) established orbit around the Red Planet. Using an advanced suite of scientific instruments - which include cameras, spectrometers, and radar - this spacecraft has been analyzing landforms, geology, minerals and ice on Mars for years and assisting with other missions. While the mission was only meant to last two years, the orbiter has remained in operation for the past twelve.