Astronomers have found evidence that there is a huge body of liquid water buried near the south pole on Mars. The Guardian reports that water is located near an area called Planum Australe, and that it is the first stable body of water that has been found on the planet.
“We discovered water on Mars,” said Roberto Orosei, a member of the National Institute of Astrophysics. Orosei added that any other explanation for the bright reflections the scientists saw in their radar observations was “untenable.”
Here’s what you need to know about the Mars underground lake:
1. Scientists Have Been Searching for Water on Mars for Three Decades
While the discovery is certainly new, the theory that Mars could be home to several bodies of water is not. It was first proposed by Steve Clifford, a planetary scientist specializing in water on Mars at the Planetary Science Institute in Arizona in the 1980s. Clifford, according to Space.com, was inspired by scientists’ studies of lakes below the Antarctic and Greenland ice sheets, and felt that he could apply the same logic to uncover water below the ice caps on Mars.
The new research attempted did just that by using radar data gathered by a device called MARSIS. The device uses pulses of radar to study the planet’s interior structure. Space.com reports that it has been orbiting the planet aboard Mars Express since 2003. Clifford was not involved in the discovery.
“MARSIS was able to detect echoes from beneath the southern polar cap of Mars that were stronger than surface echoes,” said Orosei. “This condition on Earth happens only when you observe subglacial water like in Antarctica over places like Lake Vostok.” The astronomy team has yet to determine whether The scientists can’t figure out precisely how deep the lake is, but they have confirmed that it is roughly 12.5 miles in length, and likely contains salt, explaining why it stays liquid at extremely cold temperatures.
2. Scientists Believe That Mars Was Once Covered In Water Similar to Earth
According to National Geographic, scientists believe that Mars was once covered in bodies of water, much like our planet Earth. Over time, the bodies of water dissipated, leaving the barren desert that we see through telescopes today. “We know there was a lot of water on Mars’s surface, and we can’t quite account for all of it today,” says Bobby Braun, a professor at the University of Colorado.
Scientists have previously found water on the surface of Mars, but it was always “transient or inaccessible,” and was locked into permafrost caps or hovering in the atmosphere. The underground lake is the first time a body of water has been found in its liquid form, an unlikely discovery which has not been lost on the team of astronomers who reported it. “We knew that there was something there, and we were curious to know what was under that area,” says Elena Pettinelli, a member of Italy’s Roma Tre University. “And we were stubborn enough to do the data analysis.”
“I think, we’ve done a good job in trying to kill this idea, in the sense that we have been trying to destroy the possibility that it was water many times,” Pettinelli adds. “So we are quite convinced now, and we hope to be more convinced in the future with other data.”
3. The Location of the Lake Suggests There Could Be Extra-Terrestrial Life
Mark Sephton, a researcher at Imperial College in London, told The Guardian that the location of the lake on Mars suggests that there could be extra-terrestrial life hidden underground. He explains that the surface of Mars is bombarded by intense radiation that leaves the surface sterile, so if there is life anywhere on the planet, it is liable to be underground. “As long as there is an energy source to exploit and a source of nutrients or raw materials then life is possible,” he said.
“High salt conditions are good for maintaining a liquid state but are a challenge for life,” Sephton continued. “If the salt concentrations outside of the cell are higher than the inside then it draws water out from inside the cell and the cell shrinks and desiccates. Life can adapt by synthesizing organic molecules to stop the process but there are limits, beyond which the high salinities in the cell interfere with biochemistry and the cell dies.”
Sephon concluded his statement by saying: “For Mars, some mechanisms which keep water in a liquid state can operate at levels that are too much of a good thing for life.”
4. The Tools to Properly Investigate the Lake Are Not Yet Available
Despite making what appears to be a groundbreaking discovery, the technology needed to travel to Mars and investigate the lake firsthand are not yet available. The Guardian reports that it will take some time before scientists are able to see whether there is life underneath the Martian surface.
“Getting there and acquiring the final evidence that this is indeed a lake will not be an easy task,” Orosei explains. “It will require flying a robot there which is capable of drilling through 1.5km of ice and this will certainly require some technological developments that at the moment are not available.”
Despite the fact that our technology is not advanced enough, the astronomers behind the discovery remain hopeful about the future. “There is no reason to conclude that the presence of subsurface water on Mars is limited to a single location,” adds Orosei.
5. Some Experts Are Still Skeptical Over the Discovery
Despite the evidence provided by Orosei, Pettinelli, and the rest of the astronomy team, there are some experts who find the discovery too good to be true. “I think it’s a very, very persuasive argument, but it’s not a conclusive or definitive argument,” says Steve Clifford. “There’s always the possibility that conditions that we haven’t foreseen exist at the base of the cap and are responsible for this bright reflection.”
Daniel Nunes, the Instrument Scientist for SHARAD and NASA’s Jet Propulsion Laborator, is also weary of jumping to conclusions. “I think there’s going to be a healthy debate on whether this interpretation is correct,” Nunes told Popular Mechanics. “One thing that we need to be also cautious about is that there are different kinds of materials that can produce large reflections as well… [and] I think the new processing has to withstand verification by the community.”