Radar images show subsurface Martian lake

[Judi Lynn]

David Szondy
2 hours ago

ESA has released new radar maps showing the lake buried under the south pole of Mars. The stripe-like images were produced by the agency's orbiting Mars Express spacecraft as its Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument (MARSIS) probed down to depths of 1.5 km (1 mi) to show the presence of liquid water at the base of the Martian ice cap over a 20-km-wide (12.4-mi) area of the Planum Australe.

The new images are based on repeated radar scans taken by Mars Express between 2012 and 2015, which provided enough data to confirm the presence of the Martian polar lakes. According to ESA, water ice at the poles in the form of permafrost had been detected by Mars Express over its 15-year career orbiting the Red Planet, but it required repeating passes by the orbiting ground-penetrating radar to gain enough high-resolution data to confirm the presence of the polar lakes.

This is because the radar must penetrate water ice, carbon dioxide ice, and dust before being reflected back to produce the images where blue shows the strongest reflections. During this process the radio beam is altered by the materials it passes through, which allows it to determine what those materials are, but also makes analysis very complex and requiring large data sets.

More:
https://newatlas.com/radar-mars-polar-lake/56086/