HiRISE: Tall boulder rolls downhill, lands upright

This image was targeted to cover part of a small “chaos” terrain, where there are lots of steep slopes. A closeup shows a boulder or block casting a long shadow, at the end of a boulder trail down the slope, and we can see it moved from upper left to middle right. The trail has a odd repeating pattern, as if the boulder couldn’t roll straight due to its shape… [More at link and at NASA/JPL press release]