Billions of years ago, Mars was a lush world with a temperate climate, a far cry from the arid and freezing planet we know now. To the best of our knowledge, liquid water is a necessity for life. Thus, scientists have long searched for water on our celestial neighbor, in hopes that if Mars ever did harbor life, microorganisms could have survived in the planet’s remaining reservoirs. Researchers have now discovered buried lakes of liquid water in Ultimi Scopuli, a region near the Martian southern pole.
The breakthrough discovery was made using the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument located on the Mars Express spacecraft, which has been orbiting the red planet and collecting data since 2005. MARSIS utilizes the radio-echo sounding technique, where radio waves are sent to the planetary surface. These waves get reflected differently depending on the surface they come in contact with, enabling geological structures to be imaged and their material properties identified. This method works particularly well for imaging structures under ice layers, and thus is ideal for topographical research around the Martian polar caps.
In 2018, Italian researchers had discovered a single lake under the southern polar cap, but this finding was highly disputed and many questions remained about its make-up. The new findings not only corroborated the 2018 observation, but also found three additional lakes nearby, all in liquid form. With average temperatures of around -100oC, how can these lakes not be frozen? The researchers argue that the lakes could have a high salt concentration, which would lower their freezing point. This high salt content could pose a problem for potential life. Still, if confirmed through further studies, these lakes would be the first potentially habitable regions discovered on Mars.
Elena Pettinelli, the corresponding author of the Nature Astronomy paper, is an associate professor in the Mathematics and Physics Department in Rome Tre University where she leads the Earth and Planetary Applied Physics Laboratory. Twelve other researchers from Italy, Germany, and Australia contributed to this work.
Managing correspondent: Melis Tekant
Original article: Multiple subglacial water bodies below the south pole of Mars unveiled by new MARSIS data – Nature Astronomy
Media coverage: Buried lakes of liquid water discovered on Mars – BBC
Water on Mars: discovery of three buried lakes intrigues scientists – Nature News
Image credit: NASA