Underground lake found on Mars by Italian researchers

"This is the place on Mars where you have something that most resembles a habitat, a place where life could subsist", said planetary scientist Roberto Orosei of Istituto Nazionale di Astrofisica in Italy, who led the research published in the journal Science. But now, after analyzing data collected by the Mars Express orbiter over the past 15 years, scientists have come to the stunning conclusion that there is liquid water underneath the South Pole of the planet.

The discovery was made using MARSIS, the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, housed within the Mars Express orbiter.

Between May 2012 and December 2015, MARSIS was used to survey the Planum Australe region, which is in the southern ice cap of Mars.

They obtained 29 sets of radar samplings, mapping out an area exhibiting a very sharp change in its associated radar signal, about 1.5 kilometers below the surface of the ice and extending sideways about 20 kilometers. For this water to remain in a liquid state, the team believes that there are various salts saturating the liquid, keeping it from freezing over.

Space agency NASA's Curiosity Rover had found that liquid water does flow intermittently on Mars and it also detected that water had existed there in the past.

Located under a layer of Martian ice, the lake is about 20km wide, says the report led by Italian researchers in the USA journal Science.

Almost 4.5 billion years ago, Mars had six and a half times as much water as it does now and a thicker atmosphere. Experts believe this raises the possibility of finding life on the red planet.

"For water to exist under the surface it has to be deep and really salty, and that last part is significant because that is exactly the type of place you go look for lifeforms".

Scientists operating ground-penetrating radar on board the European Space Agency's Mars Express spacecraft, which is orbiting the red planet, announced the finding on Wednesday, ending decades of speculation.

Given that the ghostly shadows of Mars' watery past cover the planet, the existence of liquid water beneath its surface had always been suspected by scientists. There are obvious parallels to Antarctica, where lakes have been discovered beneath glaciers in several areas of the otherwise frozen continent.

Still, it's a breakthrough, the first substantial body of water found on Mars, not millions of years ago, but today.

"Nobody dares to propose that there could be any more complex life form", Orosei said.

The tool is called the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), and was created to find subsurface water by sending radar pulses that penetrate the surface and ice caps.

The discovery is the latest of many breakthroughs by Nasa's Mars missions. When they found evidence of the subterranean lake, they were careful not to jump to conclusions, the scientists told NPR.

  • Joe Gonzales