Mars Odyssey THEMIS Image: Nilosyrtis Mensae
The floors of these craters contain very interesting and enigmatic materials which may contain shallow subsurface ground ice with varying amounts of a sediment covering (mantle). When ice is covered with a critical thickness of sediment it is actually insulated and can survive longer than cleaner exposed ice. The ablation and sublimation of the ice causes a chaotic topography to develop with high and low regions. This may explain the relief seen on the crater floors. The terrain outside of the craters appears muted because it is most likely mantled with a dusty icy covering. This region of Mars is located along the highland/lowland boundary dichotomy. [Source: ASU THEMIS Science Team] Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.
Image Credit: NASA/JPL/Arizona State University | ||||||||||||||||||||
[ Show Full-Size Image (GIF) ] [ Show Full-Size Image (JPG) ] | ||||||||||||||||||||
[ Show Full-Size Image (PNG) ] [ Show Full-Size Image (TIF) ] | ||||||||||||||||||||
[ Printer-friendly version ] | ||||||||||||||||||||
|