Discovered by a team of Italian scientists using three year's worth of data from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument on the European Space Agency's Mars Express orbiter, the potential lake is at least a few meters deep, and might be a fixed, steady feature of the subsurface. They have also detected water ice and seen drops of condensation on spacecraft. This new discovery suggests that there had always been liquid water on Mars, but we had been looking in the wrong place. Where this water went and how, taking most of Mars' atmosphere with it, is one of the great and ominous environmental mysteries of our time. Water is now driving NASA's exploration into the outer solar system, where ocean worlds - like Jupiter's moon Europa and Saturn's moon Enceladus - hold the potential to support life.
"I've been studying life in ice for 35 years", he said.
What they believe to be a lake sits beneath the Red Planet's south polar ice cap, and is about 20km across. But Clifford holds out hope subsurface geothermal hotspots like those that power volcanoes and hot springs on Earth could sufficiently heat portions of the Martian underworld to allow liquid reservoirs to exist there without the need for life-sabotaging salt levels. "This condition on Earth happens only when you observe subglacial water, like in Antarctica, over places like Lake Vostok".
Despite the obvious excitement surrounding the findings, Mars' surface is "inhospitable to life", according to the Open University's Dr. Manish Patel, and researchers are not any closer to finding life than they were prior to the announcement. Microbes are amazingly good at finding ways of surviving, once they exist.
"It's probably not a very large lake", Professor Roberto Orosei, who led the study, said.
Jeffrey Plaut of NASA's Jet Propulsion Laboratory said in an email that the interpretation that it is liquid water is "certainly plausible, but it's not quite a slam dunk yet". Coincidentally, one of these zones lies right over the new study area where the unusual signal was found, Bramson said.
The European Space Agency’s Mars Express spacecraft used radar to detect a lake of liquid water on the Red Planet
It has taken the persistence of scientists working with this subsurface-probing instrument to develop new techniques in order to collect as much high-resolution data as possible to confirm their exciting conclusion. Oh, you can't. It's been forced into a drastic hibernation by deadly dust storms so intense they've engulfed the entire planet.
Coates' own next mission, the rover Exomars, will set off for the planet in 2020 and is scheduled to arrive in 2021.
Even if this new discovery is validated, experts are lukewarm about whether this body of water would be suitable for life. Coates thinks the chance of finding it has just gone up. But the spacecraft's eccentric orbit oscillates between distances of 220 miles and 6,200 miles from the Martian topography, giving the team relatively brief periods of time to probe beneath the ice.
The readings were taken between May 2012 and December 2015, says the release.
And although Antarctica is hard to get to, it's a lot easier than Mars.
Beneath this, researchers spotted something unusual 1.5km under the ice. "People have talked about melting through Enceladus's ice, and maybe that would work, but it's not easy".
And on the last day of the month, Mars will reach its highest point around midnight, and will be visible roughly 35 degrees above the southern horizon, or one-third of the distance between the horizon and overhead.