This site along a Coprates Chasma ridge shows what are called recurring slope lineae (or RSL) on generally north-facing slopes in northern summer/southern winter (latitude 12.9 degrees S, longitude 295.5 degrees E). With an animation constructed from multiple co-located images, we can detect surface change and constrain the RSL phenomena.

An enhanced color image illustrates the “greenish” fans and deposits associated with RSL. Two of these fans transition downslope into ripples. (HiRISE IRB color–near-infrared, red, and blue-green bandpasses–are displayed as red, green, and blue, respectively).

All of the lineae here and in the larger scene appear to originate from relatively bright bedrock outcrops. Some of the fans that RSL flow over became darker and brighter over time. Image is approximately 950 meters wide.

Also see http://www.uahirise.org/sim/2013-12-10/ .

Written by: Matthew Chojnacki   (29 January 2014)

More info and image formats at http://hirise.lpl.arizona.edu/ESP_029226_1670

Image: NASA/JPL/University of Arizona