Buried Lakes on Mars

Mars south polar region
Fenton & Hayward (2010)

Utilizing the ESA's Mars Express Orbiter, Lauro et al. 2020 reported in Nature Astronomy the potential discovery of additional large water ponds or lakes under the Martian surface. The deposits were identified near the south polar region of Ultimi Scopuli (circled in red on the photo) using the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument. This extends the 2018 work by Orosei et al. 2018 on radar evidence of subglacial liquid water near the south polar region.

Operating between 1.8 and 5mhz, MARSIS reflects 10W radio waves off the surface at a repetition frequency of 127.7 hz. Water has a unique higher reflection property than the surface. With multiple passes by the orbiter, the surface area of interest can get scanned at slightly different regions revealing a region that indicates the potential of a pond or lake. The researchers used data gathered from 2010 to 2019 from MARSIS to strengthen the overall evidence.

Described as lakes and ponds, the water is most likely a slush-like, high saline solution that is pooled about 1 mile under the surface with a temperature of about -90F.

Though it is still too early to fully confirm the discovery of subglacial lakes, this is mounting evidence that should help drive more missions that can eventually use water to fuel hydrogen for Martian bases and/or missions.