Southern spring on Mars brings sublimation of the seasonal dry ice polar cap. Gas trapped under the seasonal ice sheet carves channels on its way to escaping to the atmosphere.
At this site, the channels are wider than we see elsewhere on Mars , perhaps meaning that the spider-like (or more scientifically, “araneiform”) terrain here is older, or that the surface is more easily eroded. Seasonal fans of eroded surface material pointed in two different directions are deposited on the remaining ice.
Written by: Candy Hansen (audio: Tre Gibbs) (11 January 2017)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_047718_0995
Image: NASA/JPL/University of Arizona