Using ground penetrating radar the European Space Agency has detected liquid water underneath the frozen Planum Astrale region of Mars. By observing how electromagnetic waves reflect off different layers underground they’ve spotted signals characteristic of liquid water.
On Wednesday, the research was published by the Italian Space Agency in the journal Science
This data was obtained by the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument i.e. MARSIS on the European Space Agencys Mars Express Spacecraft
Mars Express Spacecraft courtesy of ESA
The presence of liquid water on Mars has implications for astrobiology i.e. the possibility extraterrestrial life, as well as space exploration and colonization. Water can be used for life support or to create fuel via hydrolysis both of which are vital to humanities continued expansion in to outer space.
MARSIS surveyed the Planum Australe region between May 2012-December 2015 sending radar pulses through polar ice caps. Using this method which is central to dozens of surveillance technologies patented by the US government, they obtained 29 different samples which indicate a drastic change almost one mile below the surface.
This anomaly appeared very similar to lakes underneath the Greenland and Antarctican ice sheets indicating a divergence from surrounding solid matter due to an increase in reflectivity.
“Quantitative analysis of the radar signals shows that this bright feature has high relative dielectric permittivity (>15), matching that of water-bearing materials. We interpret this feature as a stable body of liquid water on Mars.”
The anomaly stretched for 12.5 miles across Planum Australe.
From Journal Science
“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,” said Roberto Orosei in a statement. Orosei is the lead study author and principal investigator of the MARSIS experiment.
Since the readings were taken below one of the coldest regions on Mars you ‘d expect that it would remain frozen however salt compounds found on the planet could theoretically aid in retaining a liquid state by creating a type of brine. The pressure of the ice above it may play a role as well. More dense solid matter floats to the top of liquid similar to how lakes are frozen at the surface on Earth. So technically any liquid water would be more likely to exist underneath ice rather then on the surface.
Example of Underground Lake on Earth @ Lost Sea
“The long duration of Mars Express, and the exhausting effort made by the radar team to overcome many analytical challenges, enabled this much-awaited result, demonstrating that the mission and its payload still have a great science potential,” said Dmitri Titov in a statement, Mars Express project scientist.
“This thrilling discovery is a highlight for planetary science and will contribute to our understanding of the evolution of Mars, the history of water on our neighbor planet and its habitability.”
“The lake could possibly host life, despite the extreme cold and salinity, as microbes survive on Earth in similar conditions”, claims lead author Roberto Orosei.
“It is not a place where life would be expected to have an easy time, but it is possible based upon terrestrial analogues,” said the researcher, who also serves as principal investigator of the MARSIS experiment.