This HiRISE image, approximately 1.5 by 3 kilometers , shows frosted gullies on a south-facing slope within a crater.
At this time of year only south-facing slopes retain the frost, while the north-facing slopes have melted. Gullies are not the only active geologic process going on here. A small crater is visible at the bottom of the slope.
Written by: Livio Tornabene, Ryan Hopkins, Kayle Hansen and Eric Pilles (audio: Tre Gibbs) (17 December 2014)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_039114_1115
Image: NASA/JPL/University of Arizona