Skip to main content

Could there be underground lakes on Mars’s southern pole?

The bright white region of this image shows the icy cap that covers Mars’ south pole, composed of frozen water and frozen carbon dioxide. ESA’s Mars Express imaged this area of Mars on Dec. 17, 2012, in infrared, green and blue light, using its High Resolution Stereo Camera.
The bright white region of this image shows the icy cap that covers Mars’ south pole, composed of frozen water and frozen carbon dioxide. ESA’s Mars Express imaged this area of Mars on Dec. 17, 2012, in infrared, green, and blue light, using its High Resolution Stereo Camera. ESA/DLR/FU Berlin/Bill Dunford

The question of how to access water on Mars is a big one if we eventually want to send a crewed mission there. As far as we can tell, Mars doesn’t have liquid water on its surface now, but it does have large amounts of ice at its poles as well as subsurface ice in other regions. Locating exactly where this subsurface ice is and how accessible it is is a major question to be answered by the upcoming Mars Ice Mapper mission.

Now, a new study using data from an orbiter suggests that there could be large subsurface ‘lakes’ on Mars, although how there could be liquid water in such a cold environment remains unclear.

Researchers used data from Mars Express, the European Space Agency’s orbiter which uses radar as well as a high-definition camera to image the planet. The radar data shows signals around the south pole which suggests the presence of underground lakes. This concept was first floated in 2018, when different researchers used data from the same orbiter to locate the first lake. This new study has found dozens of similar signals.

However, Mars gets very cold and this far south, it is thought to be too cold for water to remain in its liquid form. So it’s not clear how to explain the radar signals.

“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,” said Jeffrey Plaut of JPL, co-principal investigator of the orbiter’s MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) instrument. “Either liquid water is common beneath Mars’ south pole or these signals are indicative of something else.”

Some of the signals found less than a mile from the surface, where the estimated temperature would be minus 81 degrees Fahrenheit (minus 63 degrees Celsius). At that temperature, the water would be frozen even if it contained salts which lower its freezing temperature. There is a possibility that underground volcanic activity could raise the temperature enough to keep water liquid, although this kind of activity hasn’t yet been identified in the area.

“They found that it would take double the estimated Martian geothermal heat flow to keep this water liquid,” said Aditya Khuller, co-author of the paper. “One possible way to get this amount of heat is through volcanism. However, we haven’t really seen any strong evidence for recent volcanism at the south pole, so it seems unlikely that volcanic activity would allow subsurface liquid water to be present throughout this region.”

The research is published in the journal Geophysical Research Letters.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
NASA has lost communication with the Ingenuity Mars helicopter
NASA’s Ingenuity Mars helicopter is seen here in a close-up taken by Mastcam-Z, a pair of zoomable cameras aboard the Perseverance rover. This image was taken on April 5, the 45th Martian day, or sol, of the mission.

The Mars helicopter Ingenuity has had a remarkable lifespan and has proven to be a greater success than anyone imagined. Originally designed to perform just five flights over the surface of Mars, the helicopter has now performed more than 70. However, NASA has now announced that it has lost contact with the helicopter, though it's unclear how serious this problem is.

The helicopter was performing its 72nd flight, which was an adjustment and correction to a previous flight that was cut short. Flight 71 was intended to be a journey of 1,175 feet (358 meters), but when the helicopter made this flight earlier in the month, it traveled just a third of that. The problem was related to its downward-facing camera, which uses surface indications for autonomous navigation. The helicopter was traveling over a particularly featureless expanse of the surface, and the lack of landmarks appeared to cause a problem with its navigation, forcing the flight to end early.

Read more
See the passing of a day on Mars with the Curiosity rover
Curiosity rover

While many of us are on vacation this week between Christmas and New Year, the Curiosity rover on Mars is getting back to work after taking time off last month. In November, NASA's Mars missions paused for two weeks during an event called the Mars solar conjunction, when the sun is directly between Earth and Mars.

That means that any communications signals passing between the two planets would have to pass close to the harsh solar environment, where they would likely be degraded. To avoid any risk of garbled communications sending dangerous signals to the rovers, NASA stopped sending commands to both its Curiosity and Perseverance rovers until the solar conjunction passed.

Read more
Mars Odyssey spacecraft pulls a sideways maneuver to capture the planet’s horizon
NASA Orbiter Snaps Stunning Views of Mars Horizon

A new image from a NASA orbiter shows an unusual view of Mars that captures the planet's horizon complete with clouds. It is similar to the kinds of views of Earth that astronauts get from the International Space Station, showing what Mars would look like if seen from a similar vantage point.

The image was taken by NASA's Mars Odyssey spacecraft, which has been orbiting the planet since 2001. In its over 20 years of operations, the orbiter made key discoveries, including some of the first detections of subsurface ice on the planet. It has also created a global map of the planet's surface using its Thermal Emission Imaging System (THEMIS) instrument.

Read more