When scientists first found signs of a lake under Mars’ south pole in 2018, questions abounded over how such a feature could form and whether the measurements were accurate. Now, a study published this week in Nature Astronomy not only confirms the size and location of the first lake, but also shows three more, smaller bodies of water nearby.
The study adds 100 measurements to the team’s original 29 figures for a clearer picture of the region. The four lakes are hidden a mile under the surface of Mars’ icy south pole, and may be full of salt and sediments to remain liquid even in extreme cold temperatures. Some scientists not involved in the study are cautious about the research team’s conclusions, but the study authors see the discovery as an optimistic signal in the search for life on Mars.
“Here we have not just an occasional body of water, but a system,” Roma Tre University planetary scientist Elena Pettinelli, a co-author on the study, tells Nadia Drake at National Geographic. “The system was probably existing a long time ago, when the planet was very different, and this is maybe the remnant of that.”
Even if the lakes are inhospitable for life, the fact that the south pole holds multiple water features suggests that they might be the last remnants of the Red Planet’s ancient oceans. Mars is covered in the signs of erosion that suggest water once flowed across its now dry, rocky surface. Observations made by the Curiosity rover suggest that Mars used to be covered in a vast ocean, Colin Schultz wrote for Smithsonian in 2013.
“As the early Martian climate cooled, such an ocean would have frozen and eventually sublimed away,” or evaporated from solid ice into water vapor without melting first, Planetary Science Institute researcher