English: Flow-like features on Dunes in Richardson Crater, Mars. They form around the dark dune spots, in the debris of the hypothesized Martian Geysers. The dark material at the end of the flows moves at between 0.1 and 1.4 m/day in late spring / summer on Mars. This example moves approximately 39 meters in 26 days between the last two frames. All the current models for it favour processes involving liquid water as a cause. Either interfacial layers, or else layers of water created through the solid state greenhouse effect. ^[1][2][1]

Animation centered on Lattitude -72.02, Longtitude, 179.408. Displayed region is 188.5 meters by 172 meters in size. Dates of the sequence: 19 January (sol 396), 24 January (sol 401), 29 January (sol 406), 10 February (sol 418), and 09 March (sol 444), all taken in 2009. The photos were all taken between 4.10 pm and 4.28 pm in Mars local time.

(For the sols there, I used this date to sol calculator as the original images don't have sol numbers on them, just acquisition date, and the time taken in Mars local time)

I made this animated gif using HiView: the image viewer for the HiRISE database and the images

ESP_011640_1080 : 19 January 2009, 4:14 PM Mars local (sol 396)
ESP_011706_1080 : 24 January 2009, 4.22 pm Mars local (sol 401)
ESP_011772_1080 : (29 January 2009, 4:28 PM Mars local(sol 406)
ESP_011917_1080 : 10 February 2009, 4:21 PM Mars local (sol 418)
ESP_012273_1080 : 09 March 2009, 4:10 PM Mars local (sol 444).

Since the images are taken centered at different points on the Mars surface, it is impossible to line up all the features exactly between the images. I've aligned the flow like features in the vertical center of the image by preference.

This is produced under the NASA image guidelines terms for reuse, see Photo guidelines