Underground lakes of liquid water potentially discovered on Mars

29 Sep 2020

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Following research carried out in 2018, scientists have found more evidence of a large reservoir of liquid water under the surface of Mars.

Two years ago, scientists detected what appeared to be a pool of liquid water buried beneath layers of ice on Mars, which would confirm a long-suspected theory.

Now, new research published in Nature Astronomy has revealed more evidence of that lake discovery, as well as few more bodies of water.

The 2018 investigation, which used the ESA’s Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), showed that the south polar region of Mars is made of many layers of ice and dust down to a depth of 1.5km in an area 200km wide.

After analysing the results, a particularly bright 20km-wide spot was found, which was interpreted to be a stable body of liquid water, laden with salty, saturated sediments.

What’s new about this discovery?

While the original findings were based on 29 observations collected by MARSIS between 2012 and 2015, the latest research, carried out by many of the same researchers, used a much bigger data set. This time, the team analysed 134 radar observations gathered between 2012 and 2019.

Elena Pettinelli, co-author and researcher at Roma Tre University in Italy, said that as well as confirming the position, extent and strength of the reflector from the 2018 study, the latest research showed three new bright areas.

“The main lake is surrounded by smaller bodies of liquid water, but because of the technical characteristics of the radar, and of its distance from the Martian surface, we cannot conclusively determine whether they are interconnected.”

Another co-author of the study, Sebastian Lauro, said the interpretation that best reconciles all available evidence is that the high-intensity reflections are coming from “extended pools of liquid water”.

According to the study, the new ponds are “patchy water pools or wet areas of smaller extent” and are separated from the main lake by strips of dry land.

As with the 2018 discovery, the fact that these potential ponds are still liquid at such low temperatures would suggest that the underground lakes are extremely salty.

Could this mean life on Mars?

The evidence of liquid water detected by the MARSIS has reinvigorated the debate about the stability of liquid water under present-day conditions on Mars.

Whether or not the latest discovery may mean the possible presence of life on Mars remains to be seen.

However, the study contained some optimism from this perspective, stating that the possibility of these extended hypersaline water bodies is “particularly exciting because of the potential for the existence of microbial life”.

Jenny Darmody is the editor of Silicon Republic