In July 2018, an international team of scientists discovered that Mars was. Using data obtained by the they suggested there was a salt water lake lurking below the cap, about 12.5 miles (about 20 kilometers wide). Because of similar phenomena seen under the Earth's ice caps, lead researcher Roberto Orosei said at the time "we had to conclude that there is water on Mars today."
Orosei's team suggested that the salts, which lower the melting point of ice, may be present in such a concentration that they enabled the lake to form.
This new study builds on that research but poses the liquid water under the ice The cap is not fully frozen over not because of salt, but because of the volcanic activity in Mars' subsurface.
Using a number of physical models, the team tried to understand the level of heat that would have to be generated in order to form the proposed underground lake. Their paper, published in Geophysical Research Letters on Tuesday, showed that one plausible solution would be if a magma chamber was present at a depth of no more than 10 kilometers below.
Their model excludes that salt alone could adequately produce the conditions needed for liquid water to form. Thus, the paper concludes that "recent magmatism may offer a plausible explanation" but without such action suggests that there may be no liquid ice in the ice cap at all.
The team suggests that NASA's InSight lander,will provide a clearer picture of how hot the Martian crust might be. Mars interior is not quite as hot as Earth, but we're not sure exactly how warm it is.
Of course, if there is liquid water then does that mean there may also be life?
"We think that if there is any life, it should probably be protected in the sub-surface from radiation, "said Ali Bramson, an author on the new paper.
On Feb. 13,which has been studying the planet from the ground for 15 years. In that time, Opportunity rather than dusty and dry
And although, sadly, Opportunity is dead, Mars may well be alive than we thought.