The formation of “recurring slope lineae” is a fascinating process on Mars that we’re just beginning to investigate, and one that we’ve imaged before in Palikir Crater .
These RSLs show up in the spring and fade in the winter. Their presence might be due to briny water, and it opens up the door to taking a fresh look at other possible RSL candidates. This observation was done to accomplish just that: to re-image a previously photographed area that might confirm if this a candidate for RSL.
When HiRISE re-images an area, we try to match the exact lighting as before, in order to see any differences. Along with a stereo pair and resulting anaglyph, our understanding of the terrain is more complete.
Written by: HIRISE Science Team (audio by Tre Gibbs) (12 September 2013)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_032562_1670
Image: NASA/JPL/University of Arizona