Dynamic seasonal activity in polar dunes, captured by multiple HiRISE passes over one cycle. Pretty awesome that this can be done, even more so from orbit. Also, just really pretty pictures.

http://www.sciencedirect.com/science/artic...019103512003971
http://www.jpl.nasa.gov/news/news.php?release=2013-034 (even has a time-lapse video)

Thanks for the links; that video is very well done (panning across the dunes whilst cycling through the seasons!) and most informative. Those almost abstract looking dunescapes have always been amongst my favorite Martian landscapes.

Airbag