English: Channel network and TAR's, as seen by HiRISE, under HiWish program Transverse Aeolian Ridges (TAR's) are seen in low portions--channel beds. This image was named HiRISE picture of the day. NASA described the picture with the following caption: This image focuses on small channels formed on the floor of the much larger Kasei Valles, one of the largest outflow channels on Mars.

The enormous floods that formed such channels sometimes flowed around either side of topographic rises forming islands with a streamlined shape. The channels in this image are located on the trailing edge of such a formation (white shaded box). The small channels formed linear coalescing pits, perhaps by ground ice sublimating into the atmosphere leaving the surface material to collapse. Much of the remaining material seems to be made up of easily eroded sediments likely deposited by the floodwaters, which have subsequently formed dunes inside the channels.

Kasei extends almost 1600 kilometers (980 miles) across the surface towards the northeast before it empties into Chryse Planitia in the northern lowlands of Mars.

Written by: Ginny Gulick (13 December 2022)