What is that “purplish“ colored stuff (in HiRISE IRB color) with the polygonal fractures in this observation? Scientists think it contains chlorides, like sodium chloride or table salt, or maybe chloride of calcium or magnesium.
These salts can be deposited during the evaporation or water in lakes or playas. These deposits are billions of years old, so it is truly old salt, not a fish tale.
Written by: Alfred McEwen (audio: Tre Gibbs) (23 March 2016)
This is a stereo pair with PSP_008780_1735 .
More info and image formats at http://hirise.lpl.arizona.edu/ESP_044502_1735
Image: NASA/JPL/University of Arizona