This image covers a 26-kilometer-wide impact crater northeast of the Hellas impact basin. The crater exposes large blocks of bedrock (called “megabreccia”) in both the central uplift and in the walls of the crater.
The enhanced-color subimage from the wall shows a large, approximately 250-meter-wide reddish block, although actually “red” in the infrared-shifted color of HiRISE. These blocks could be ejecta from the ancient Hellas impact or other large impacts from billions of years ago.
Written by: Alfred McEwen (audio: Tre Gibbs) (16 April 2014)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_035998_1555
Image: NASA/JPL/University of Arizona