- Scientists from the National Institute for Astrophysics in Bologna may have found a lake of liquid water on Mars.
- Satellite data suggests the water might lie underneath the surface of a polar ice cap.
- The researchers used radar to probe the ice cap, and their new study suggests the potential lake could be 20 kilometers long.
We've heard it before - there may be a major source of water on Mars, in ice sheets that lie just under the red planet's. But according to a new study published in the journal Science, liquid water may exist there, too.
Researchers from the National Institute for Astrophysics in Bologna in Italy used a radar tool on the European Space Agency's Mars Express satellite to probe the planet's ice caps. They believe three years' worth of data indicates there could be a lake of liquid water under the caps that stretches 20 kilometers across.
The team, led by Roberto Orosei, said this may be the first time scientists have found liquid water that can remain in a liquid state for a prolonged period of time, rather than freezing. Elsewhere on the red planet, it is too cold for water to remain a liquid - Mars' average temperature is -81 degrees Fahrenheit (-62 degrees Celsius).
"If these researchers are right, this is the first time we've found evidence of a large water body on Mars," Cassie Stuurman, a geophysicist at the University of Texas who found signs of an enormous Martian ice deposit in 2016, told the AP.
Searching for Martian water
In their paper, the researchers suggested that the lake could lie about 1.5 kilometers below the ice cap's surface. But they are not yet certain whether there is really a lake there or how deep it could be. Until a human expedition or more sophisticated Rovers can investigate the polar region further, we won't know for sure. But for now, liquid water seems to be the most likely explanation for what researchers observed.
"I really have no other explanation," Orosei told the AP.
Radar detection has proved unreliable for gathering information about Mars in the past. But after reprogramming the radar tool on the Mars Express satellite - called the Mars Advanced Radar for Subsurface and Ionosphere Sounding, or MARSIS - radar pulses were able to penetrate the surface of the ice caps.
The tool measured how radio waves traveled and behaved when traveling through Mars' ice caps, then the satellite beamed that information to Earth. This gave the team an idea of the composition under the ice caps.
Time was also not on the researchers' side, however. They had to wait for the satellite to be in the right place to observe the caps at night time, a position that has only occurred 30 times in three years.
Liquid water would have major implications for life on Mars and future human settlements
Orosei told New Scientist that a combination of calcium, magnesium, and sodium salts on Mars can lower water's freezing point, which might explain the possibility of a liquid lake.
If it exists, there's also hope that the water could potentially host life.
"It is not a place where life would be expected to have an easy time, but it is possible based upon terrestrial analogues," Orosei told New Scientist. The analogues he's referring to are places on Earth that researchers have used to mimic Mars environments to test conditions in which microbes could survive.
Finding a source of liquid water on Mars would also be exciting for the prospect that the red planet could one day host a human settlement. Both Elon Musk and NASA have released plans to send humans to Mars, maybe as soon as the 2030s.
But there are huge barriers to any colonization efforts, such as growing enough food and recycling waste. Pre-delivered supplies and habitats could sustain human life on the barren surface for a year or two, some experts say, but long term colonization is a different matter. Researchers have even highlighted concerns about how reproduction would work on Mars, should a self-sustaining settlement ever arise there, since life in space has dramatic effects on people's health.
Despite all these challenges, it's exciting that there could be an underground reservoir of water on Mars. Perhaps it could be tapped as a resource, or maybe it harbors undiscovered clues about alien life.
Plus, as Orosei said in a statement, this discovery may be a clue that Mars has other hidden bodies of water that are still waiting to be found.
"This is just one small study area; it is an exciting prospect to think there could be more of these underground pockets of water elsewhere, yet to be discovered," he said.