Artistic impression of the Mars Express spacecraft probing the southern hemisphere of Mars.
NASA is planning to launch a new rover as early as July 2020 with a mission to comprehensively determine whether life ever arose on Mars, while characterising the climate and geology of the red planet and preparing for human exploration. “Because of this, there is no reason to conclude that the presence of subsurface water on Mars is limited to a single location”. In 1987, the astronomer Stephen M. Clifford theorized that liquid water might be hiding, deep below the planet’s polar ice caps.
So the researchers did a rough calibration by registering the signal that bounced back when the radar hit the atmosphere/dusty ice boundary at the Martian surface, since the composition of these materials is pretty well understood.
The researchers, whose work is being published Wednesday in the journal Science, found the lake while studying a region called Planum Australe in the southern ice cap of Mars, researchers said.
The temperature is likely below the freezing point of pure water, but can remain liquid due to the presence of magnesium, calcium, and sodium.
“We had to come up with a new operating mode to bypass some onboard processing and trigger a higher sampling rate and thus improve the resolution of the footprint of our dataset: Now we see things that simply were not possible before”, Cicchetti said.
In the past, Mars had already been home to bodies of water as evidenced by dry bed lakes and river valleys on its surface. It took them two and a half years, though, from May 2012 to December 2015-to acquire 29 radar profiles.
He suspects Mars may contain other hidden bodies of water, waiting to be discovered. Calculating permittivity requires knowing the signal power reflected by the bright patch, something the researchers could only estimate. SHARAD has been observing the subsurface of Mars since 2006.
“What the paper found is a region in the south polar layered deposits with unusually high reflective properties”, Stuurman explained.
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”.
The Italian scientists said that “bright subsurface reflections are evident within a well-defined, 20-kilometer-wide zone” that was surrounded by “much less reflective areas”. Credits: USGS Astrogeology Science Center, Arizona State University, ESA, INAF. The inset image at lower right shows the area where radar readings were made.
The lake resembles one of the interconnected pools that sit under several kilometers of ice in Greenland and Antarctica, says Martin Siegert, a geophysicist at Imperial College London, who heads a consortium trying to drill into Lake Ellsworth under West Antarctica.
Scientists Roberto Orosei (L), Elena Pettinelli (C) and Enrico Flamini pose near a replica of the Cosmo Sky Med satellite before a news conference where they announce after first-time detection of liquid water on Mars by italian radar Italian radar MARSIS, on board the ESA’s Mars at the Italian Space Agency headquarter in Rome, Italy July 25, 2018. Still, this sounds very promising, and it’s exciting to think of the possibilities of what else might be up there.