These patterns matched the computer model predictions as to how a body of water beneath the ice cap would affect the surface.

“The combination of the new topographic evidence, our computer model results and the radar data make it much more likely that at least one area of subglacial liquid water exists on Mars today, and that Mars must still be geothermally active in order to keep the water beneath the ice cap liquid,” said research leader Neil Arnold, a professor at Cambridge’s Scott Polar Research Institute.

"The combination of the new topographic evidence, our computer model results and the radar data make it much more likely that at least one area of subglacial liquid water exists on Mars today, and that Mars must still be geothermally active in order to keep the water beneath the ice cap liquid.”.

Overall, the evidence suggests that there is liquid water beneath Mars' south polar ice cap, which is kept in a liquid state by geothermal heating, enabled due to the recent occurrence of magmatic activity in the planet’s subsurface