Radar subsurface sounding over the putative frozen sea in Cerberus Palus, Mars

The area of Mars known as Cerberus Palus, suspected of harboring a frozen body of water, has been observed by the two subsurface sounding radar MARSIS and SHARAD. SHARAD data reveal subsurface interfaces at depths ranging from ~50 m to ~150 m which could be interpreted as either the bottom of an ice sheet lying over bedrock, or an interface between two lava flows. Echoes have been analyzed to estimate the dielectric properties of the surface layer, and results favor the interpretation that no ice is present in the area.