Abstract
AbstractMeridiani Planum is one of the most intensely studied regions on Mars, yet little is known about the physical properties of the deposits below those examined by the Opportunity rover. We report the detection of subsurface echoes within the Meridiani Planum deposits from data obtained by the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument. The delay time between the surface and subsurface returns is indicative of materials with a real dielectric constant of 3.6 ± 0.6. The real dielectric constant is strongly modulated by bulk density. Newly derived compaction relationships for Mars indicate that the relatively low dielectric constant of the Meridiani Planum deposits is consistent with a thick layer of ice‐free, porous, basaltic sand. The unique physiographic and hydrologic setting of Meridiani Planum may have provided an ideal sediment trap for eolian sands. The relatively low gravity and the cold, dry climate that has dominated Mars for billions of years may have allowed thick eolian sand deposits to remain porous and only weakly indurated. Minimally compacted sedimentary deposits may offer a possible explanation for other nonpolar region units with low apparent bulk dielectric constants.
Highlights
Orbital and in situ exploration of the sedimentary deposits at Meridiani Planum has yielded important information on the occurrence and history of Martian water and potential habitability [Squyres and Knoll, 2005]
We report the detection of subsurface echoes within the Meridiani Planum deposits from data obtained by the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument
We report the detection of subsurface reflectors in MARSIS sounder data deep within the deposits of Meridiani Planum
Summary
Orbital and in situ exploration of the sedimentary deposits at Meridiani Planum has yielded important information on the occurrence and history of Martian water and potential habitability [Squyres and Knoll, 2005]. The Mars Exploration Rover Opportunity revealed that the hematite-bearing plains (HBP) include a lag of basaltic sand containing sulfates and hematitic concretions, likely derived from erosion of underlying rocks [Squyres et al, 2004]. These HBP surficial deposits, characterized by smooth plains with occasional dunes, cover weakly indurated sandstones and are relatively thin compared to the thicker, underlying friable layered deposits of the etched plains (EP). The SHARAD radar sounder which has partially or completely penetrated PLD, MFF, and other possibly ice-rich deposits, detects no subsurface reflectors in Meridiani Planum deposits despite the surface being very smooth at the instrument’s frequency [Putzig et al, 2014]. The electrical and physical properties of the Meridiani deposits are characterized in an effort to determine their origin
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
