Dark Rays and Light-Tones

This image shows a relatively youthful crater with dark rayed ejecta and a light-toned zone that extends beyond that ejecta.

The lighter-toned surface might be the “blast zone” as darker regolith material was “blown away” during the impact event. With HiRISE resolution, we can see that this is the wrong explanation. Instead, the bright ejecta consists of indurated fine materials, such as dust trapped by the roughened surface, then cemented over time.

Written by: HiRISE Science Team (audio by Tre Gibbs)   (3 April 2013)

More info and image formats at http://hirise.lpl.arizona.edu/ESP_012560_1660

Image: NASA/JPL/University of Arizona