View of Argyre Planitia and Hooke crater
View of Argyre Planitia and Hooke crater
This image shows that the interior of the Arygre basin is covered largely by frost. It is carbon dioxide 'snow' that trickles down from the clouds of the Martian atmosphere in winter. Large sections of the lower-lying regions are covered with a thin layer of carbon dioxide ice (dry ice). In higher altitude regions, this no longer occurs, except in a few places lying in shadow, such as on the slopes of the smaller craters. The carbon dioxide-ice snow then lies down for a few months as a thin veil over the landscape. Fields of dark, crescent dunes are visible in Hooke crater; these are ice-free, because the dark material absorbs the sparse atmospheric heat better and vaporises the carbon dioxide snow quickly. The higher areas in the north (right) are already free of ice.
Copyright note:
As a joint undertaking by DLR, ESA and FU Berlin, the Mars Express HRSC images are published under a Creative Commons licence since December 2014: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO. This licence will also apply to all HRSC images released to date.