In the vicinities of Halley Crater (1)

This image shows a landscape West of Mars' Argyre impact basin and North-East of Halley Crater. The large but faint circular feature near the center of the image is an unnamed impact crater about 7,5 Km (about 4,7 miles) in diameter. It has been all but erased by geological (and probably ice-related) processes. In fact, the majority of impact craters in this image have been modified from their original shapes, some undoubtedly beyond recognition. Only a few small craters remain pristine. The most prevalent surface type in this image is rough, dissected terrain, which is characterized by a complex pattern of knobs, pits, ridges and valleys. In places the rough terrain has been covered by a younger material that appears flat, smooth and nearly featureless. The smooth material may have been emplaced as muddy or icy debris. It filled low-lying areas (most notably craters) and surrounded higher features, preserving islands of rough terrain. Wind-formed dunes have formed atop some of the smooth material and diagonal streaks on the right side of the image may be due to the winds. Images such as this show the importance of water (liquid and/or ice), wind, and impacts in shaping the surface of Mars.