Cosmic Diary
Itty bitty changes: places where the wind barely moves sand
6 Jun 2016, 18:24 UTC
(200 words excerpt, click title or image to see full post)
A Piece of Mars: Not all dunes on Mars are moving at a measurable pace. This 0.96×0.45 km (0.6×0.28 mi) scene looks a lot like one I posted 3 years ago called Martian Sports. This image shows the same dunes 9.5 years apart (that’s 5 Mars Years). There are a few places where patches of sand have appeared or been removed, but it would take some detailed work to figure out whether the bulk of the dunes has shifted much. In the first post I guessed that the upper dune would crash into its topographic hurdle in 20 years, but after nearly 10 years of relative inactivity, I’ll have to revise that estimate upwards to perhaps 100 years. (HiRISE <a href="http://www.uahirise.org/ESP_045785_1995"ESP_045785_1995 NASA/JPL/Univ. of Arizona)