Lomonosov Crater in Winter

NASA JPL and Malin Space Science Systems released a Mars Global Surveyor image of the crater Lomonosov. According to NASA “It is still winter in the northern hemisphere of Mars. On April 20, 2000, the Mars Orbiter Camera (MOC)
onboard Mars Global Surveyor (MGS) captured this view of a chilly Lomonosov Crater. The rims of the crater appear white because they are covered with wintertime frost. A dark patch just right of center on the crater floor
is a sand dune field. Both low-lying ground fogs (fuzzy, patchy areas around the lower perimeter of the crater) and higher cloud layers (fuzzy white arcs seen within the crater and towards the upper right) obscure much of the surface. “