Cosmos Editorial
NASA’s High Resolution Imaging Science Experiment (HiRISE), currently orbiting Mars, snapped this false-colour image of an impact crater and ejecta on the red planet’s surface.
Impact ejecta is material that is thrown up and out of the surface of a planet when a meteorite, asteroid or comet crashes into it. Material that was originally beneath the surface of the planet rains down on the newly formed impact crater.
Some of this material is deposited close to the crater, folding over itself to form the crater rim, visible here as a yellowish ring. Other material is blasted out faster and falls down further from the crater rim creating two types of ejecta: a “continuous ejecta blanket” and “discontinuous ejecta.” Both are shown in this image. The blocky area at the centre of the image close to the yellowish crater rim is the “continuous” ejecta. The discontinuous ejecta is further from the crater rim, streaking away from the crater like spokes on a bicycle.
