Almost 3 years after scientists confirmed that the Red Planet still has lakes filled with liquid water, a new study suggests there may be more water than previously thought, including “dozens” of lakes less than a mile beneath the surface of Mars, the Mail reported.

Researchers from NASA’s Jet Propulsion Laboratory analyzed data from the European Space Agency’s Mars Express orbiter and saw dozens of radar reflections around the Martian south pole similar to the discovery made in 2018.

The radar signals were discovered in a region of the Red Planet known as the South Polar Layered Deposits, home to water ice, dry ice and dust that have lived there for millions of years.

Nonetheless, many of these discoveries are in areas that are likely too cold for water to remain liquid, even with the presence of salty minerals known as perchlorates, a fact that has currently baffled the researchers.

In a statement, study co-author and NASA JPL investigator Jeffrey Plaut said: “We’re not certain whether these signals are liquid water or not, but they appear to be much more widespread than what the original paper found.”

“Either liquid water is common beneath Mars’ south pole or these signals are indicative of something else.”

In March, a separate study indicated that between 33 and 99% of the Red Planet’s “missing water” could be hiding under its crust, thanks to billion-year old rocks that have the ability to store the water.

The planet’s surface has an estimated temperature of around minus 63 degrees Celsius, which would be too cold for the water to stay liquid.