A major new study of Mars published in the science journal Nature Astronomy has revealed several bodies of water under the surface at the planet’s south pole.
Researchers believe the new findings bolster previous research, which suggested the possibility of a large saltwater lake beneath the surface of Mars. The research is exciting scientists because liquid water is a key ingredient to life as we know it, and new findings could pave the way to further knowledge of alien life, they speculate. It’s known, for example, that similar lakes beneath glaciers on Earth are home to microbial life. Could the same be true for Mars?
The discovery was made thanks to a tool called MARSIS, the Mars Advanced Radar for Subsurface and Ionosphere Sounding, which is a low-frequency, pulse-limited radar sounder and altimeter instrument developed by a Rome university. It’s currently on board the European Space Agency’s Mars Express spacecraft orbiting Mars, where it sends radio waves into the planet’s surface and ice caps. These waves then bounce back towards the spacecraft, which measures and collects data about the returning pulse, allowing researchers to understand more about the planet’s matter.
According to the Independent, the MARSIS helped researchers make a previous breakthrough when a large underground lake was found during a study in 2018. However, at that time there was some skepticism regarding the findings and data collected. In order to clearly determine whether the body of water was liquid, researchers felt they needed to investigate further.
To do so, a team led by planetary scientist Elena Pettinelli from Roma Tre University looked to existing methods to study the lakes beneath Earth’s Antarctic glaciers, using satellites in orbit to bounce pulses back and forth. In doing so, they were able to compare data obtained from MARSIS of the area surrounding the body of water found on Mars, which allowed them to confirm that it was in fact liquid. The method also allowed researchers to locate a number of other wet patches around the larger body of water under Mars’s surface, suggesting a number of salty lakes.
“Not only did we confirm the position, extent and strength of the reflector from our 2018 study but we found three new bright areas,” said Professor Pettinelli, who is also an author on the study published in Nature Astronomy.
“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,” she said in a statement.
The subsurface lakes appear to be “hypersaline solutions” — extremely briney liquid with high concentrations of salt — which may explain why they are not frozen solid, given the extreme cold of Mars’ south pole.
The number of lakes also suggests their formation was a natural occurrence and that they have likely existed in several permutations throughout the planet’s history. If the lakes have been a consistent presence through long stretches of time, researchers believe they could have hosted alien life when Mars had a more hospitable environment. Perhaps, they speculate, some of the descendants of these life forms remain.
“While the existence of a single subglacial lake could be attributed to exceptional conditions such as the presence of a volcano under the ice sheet, the discovery of an entire system of lakes implies that their formation process is relatively simple and common, and that these lakes have probably existed for much of Mars’ history,” said Roberto Orosei, principal investigator of the MARSIS experiment.
“For this reason, they could still retain traces of any life forms that could have evolved when Mars had a dense atmosphere, a milder climate and the presence of liquid water on the surface, similar to the early Earth.”
Researchers hope more studies in the future will examine whether alien life — or “astrobiological activity,” as it’s also called — can definitively be discovered on the planet.
