Universe Today is reporting that a recent landslide on Mars looks to be triggered by a small (under 1 meter) rock hitting the surface of the planet. The landslide is less than three years old, and a new impact crater near the top appears to be the culprit.
Go to the UT article to get details. And look at the bigger version there of the image taken by the HiRISE camera; there's a much larger crater near the bottom of the slide, and you can see where the dust rolled into it and up the far slope of the crater wall, but only partway! It's yet another amazing shot of the dynamic surface of this nearby world.