Remnants of water once found on the surface of Mars may be hidden in a handful of small lakes below the Red Planet’s south pole, and more could exist, according to new research.
For decades, researchers have suspected that water lurks below the polar icecaps of Mars, just as it does here on Earth. In 2018, scientists detected evidence for such a reservoir on the Red Planet — signs of a lake about 12 miles (19 kilometers) across and hidden below about a mile (1.5 km) of ice at the south pole of Mars.
At the time, the researchers said that studying this underground pool of water could yield insights on the past and present chances for life on Mars. However, scientists had many more questions than answers about the origin, composition and longevity of this lake and its water.
In the new study, to learn more about this hidden water, researchers used the MARSIS radar sounder instrument on board the European Space Agency’s Mars Express spacecraft to scan a 155-by-185 mile (250-by-300 km) area surrounding the suspected underground lake. The scientists analyzed this radar data with techniques previously used to detect lakes under glaciers in Antarctica.
The scientists confirmed the liquid nature of the previously observed lake, narrowing down its dimensions to about 12 by 18 miles (20 by 30 km) in size. They cannot say how deep this lake extends, as the radio waves from MARSIS cannot penetrate salty water, study co-author Elena Pettinelli, a geophysicist at Roma Tre University in Rome, told Space.com.