Lake discovery raises hope of life on Mars
Scientists have found evidence of a 12-mile wide water lake on Mars.
Dissolved salts are believed to keep the water fluid, despite it having a temperature below water’s normal freezing point.
The discovery has major implications for the chances of life surviving on the Red Planet. It is the first time a large stable body of liquid water has been confirmed to exist on Mars.
An Italian team of scientists detected the lake while carrying out a radar survey using the Mars Express spacecraft.
A 12-mile wide lake of liquid water lies beneath the southern ice cap of Mars, scientists have learned.
Dissolved salts are thought to keep the water fluid, despite it having a temperature below water’s normal freezing point.
The discovery, which has major implications for the chances of life surviving on the Red Planet, was made by an orbiting European probe using ground-penetrating radar.
It is the first time a large stable body of liquid water has been confirmed to exist on Mars. The lake, similar to those beneath the Antarctic and Greenland ice sheets on Earth, lies about 1.5 kilometres (0.9 miles) below the surface of a region called Planum Australe, close to the Martian south pole, and stretches for about 20km.
With surface temperatures as low as -68C, it would not exist as a liquid under normal conditions. But dissolved salts of magnesium, calcium, and sodium – known to be present in Martian rocks – are thought to maintain the briny miniature sea by reducing the melting point of water to -74C.
An Italian team of scientists detected the lake while carrying out a radar survey using the Mars Express spacecraft.
Between 2012 and December 2015, the Planum Australe region was mapped by the Mars Advance Radar for Subsurface and Ionosphere Sounding( mars is) instrument carried on the orbiter.
Radio waves beamed down to the surface by Marsis penetrated through the ice and
bounced back to the spacecraft. Among the 29 radar samplings, the scientists spotted a series of unusually strong reflections bearing a distinct electrical hallmark.
They revealed the presence of liquid water.
Professor Roberto Orosei, from the University of Bologna, wrote in the journal Science: “Anomalously bright subsurface reflections are evident within a well-defined 20km-wide zone which is surrounded by much less reflective areas.
“Quantitative analysis of the radar signals shows that this bright feature has high relative dielectric permittivity (electrical polarisation) matching that of water-bearing materials.
“We interpret this feature as a stable body of liquid water on Mars.”
The lake may exist as a layer of clear water, or possible be mixed with soil to form a sludge. Either way, the discovery greatly increases the chances of extraterrestrial life existing on Mars.
Liquid water is an essential requirement of life as we know it.
Billions of years ago, Mars is thought to have had oceans and rivers, much like Earth. If large bodies of liquid water lie beneath Martian polar ice, they could theoretically harbour living microbes to this day.