Buried lakes of liquid water discovered on Mars

Two years ago_ planetary scientists reported the discovery of a large saltwater lake under the ice at Mars s south pole_ a finding that was met with excitement and some scepticism. Now_ researchers have confirmed the presence of that lake  and found three more. Liquid water is vital for biology_ so the finding will be of interest to researchers studying the potential for life elsewhere in the Solar System. But the lakes are also thought to be extremely salty_ which could pose challenges to the survival of any microbial life forms. Billions of years ago_ water flowed in rivers and pooled in lakes on the Martian surface. But Mars has since lost much of its atmosphere_ which means water can't stay liquid for long on the surface today. Referring to the sub-surface lakes_ co-author Dr Roberto Orosei_ from Italy's National Institute of Astrophysics in Bologna_ told "It's even more likely that these bodies of water existed in the past. "Of course_ the implication of this is that you would have a habitat or something that resembles a habitat... that lasted throughout the history of the planet_" "As Mars was undergoing its climatic catastrophe and turning from a relatively warm planet - though it's not clear how warm - to a frozen waste_ there was a place where life could adapt and survive." The latest discovery was made using data from a radar instrument on the European Space Agency's (Esa) Mars Express spacecraft_ which has been orbiting the Red Planet since December 2003. The main lake (centre) is surrounded by at least three smaller bodies of water In 2018_ researchers used data from the Marsis radar to report signs of a 20km-wide subsurface lake located 1.5km under Mars' south polar layered deposits_ a thick polar cap formed by layers of ice and dust. However_ that finding was based on 29 observations collected by Marsis between 2012 and 2015. Now_ a team including many of the same scientists from the 2018 study have analysed a much bigger dataset of 134 radar profiles gathered between 2010 and 2019. "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 co-author Elena Pettinelli from Roma Tre University in Italy. "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."