The team say life almost certainly can’t exist on the surface of the planet due to radiation from the Sun, however, ice deposits in the mid-latitudes could theoretically provide a shield from that radiation while still allowing enough sunlight through to sustain microbial life.
The researchers calculated what that middle ground would be, and say ice with just point zero one to point one per cent of dust in it could provide a habitable area about 5-38 centimetres deep and – in cleaner ice, even more habitable areas could be possible between 2.15 and 3.1 metres deep.
They say this is all theoretical and just because life could exist there, doesn’t mean that it does, but their calculations provide a description of where the search for life on Mars should focus.