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Subsurface Radar Sounding of the South Polar Layered Deposits of Mars

Gurnett, Donald A.; Stofan, Ellen R.; Frigeri, Alessandro +21 more

The ice-rich south polar layered deposits of Mars were probed with the Mars Advanced Radar for Subsurface and Ionospheric Sounding on the Mars Express orbiter. The radar signals penetrate deep into the deposits (more than 3.7 kilometers). For most of the area, a reflection is detected at a time delay that is consistent with an interface between th…

Martian Atmospheric Erosion Rates

Barabash, Stas; Lundin, Rickard; Fedorov, Andrei +1 more

Mars was once wet but is now dry, and the fate of its ancient carbon dioxide atmosphere is one of the biggest puzzles in martian planetology. We have measured the current loss rate due to the solar wind interaction for different species: Q(O⁺) = 1.6·10²³ per second = 4 grams per second (g s^-1), Q(O₂^…

Coupled Ferric Oxides and Sulfates on the Martian Surface

Mangold, N.; Sotin, C.; Bibring, J. -P. +9 more

The Mars Exploration Rover (MER), Opportunity, showed that layered sulfate deposits in Meridiani Planum formed during a period of rising acidic ground water. Crystalline hematite spherules formed in the deposits as a consequence of aqueous alteration and were concentrated on the surface as a lag deposit as wind eroded the softer sulfate rocks. On …

Radar Sounding of the Medusae Fossae Formation Mars: Equatorial Ice or Dry, Low-Density Deposits?

Stofan, Ellen R.; Clifford, Stephen M.; Orosei, Roberto +10 more

The equatorial Medusae Fossae Formation (MFF) is enigmatic and perhaps among the youngest geologic deposits on Mars. They are thought to be composed of volcanic ash, eolian sediments, or an ice-rich material analogous to polar layered deposits. The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument aboard the Mars Expr…

Density of Mars’ South Polar Layered Deposits

Zuber, Maria T.; Asmar, Sami W.; Smrekar, Suzanne E. +6 more

Both poles of Mars are hidden beneath caps of layered ice. We calculated the density of the south polar layered deposits by combining the gravity field obtained from initial results of radio tracking of the Mars Reconnaissance Orbiter with existing surface topography from the Mars Orbiter Laser Altimeter on the Mars Global Surveyor spacecraft and …