A network of salty ponds may be gurgling beneath Mars’s South Pole alongside a large underground lake, raising the prospect of tiny, swimming Martian life.

Italian scientists reported their findings on Monday, two years after identifying what they believed to be a large buried lake.

They widened their coverage area by a couple of hundred miles, using even more data from a radar sounder on the European Space Agency’s Mars Express orbiter.

In the latest study appearing in the journal Nature Astronomy, the scientists provide further evidence of this salty underground lake, estimated to be 12 to 18 miles across and buried a mile beneath the icy surface.

Even more tantalising, they have also identified three smaller bodies of water surrounding the lake, which appear to be of various sizes and are separate from the main lake.

Roughly four billion years ago, Mars was warm and wet, like Earth, but the red planet eventually morphed into the barren, dry world it remains today.

The research team, led by Roma Tre University’s Sebastian Emanuel Lauro, used a method similar to what has been used on Earth to detect buried lakes in the Antarctic and Canadian Arctic.

They based their findings on more than 100 radar observations by Mars Express from 2010 to 2019.

All this potential water raises the possibility of microbial life on — or inside — Mars.

High concentrations of salt are likely to be keeping the water from freezing at this frigid location, the scientists noted.

The surface temperature at the South Pole is an estimated minus 113C, and gets gradually warmer with depth.

These bodies of water are potentially interesting biologically and “future missions to Mars should target this region”, the researchers wrote.