Underground lake of liquid water found on Mars
July 25, 2018
Mars has a 20-kilometer (12.4-mile) wide lake some 1.5 kilometers underneath its surface, according to a study published in the US Science magazine on Wednesday and conducted by a team led by Roberto Orosei from the National Institute of Astrophysics in Bologna.
The spectacular find ends decades-long debate on the existence of liquid water on Mars. Liquid water is a key condition for life as it exists on Earth.
Astronomers have long known that Mars used to have rivers and oceans of liquid water billions of years ago, based on, among other things, flowing patterns on the planet's surface. More recent discoveries confirmed the presence of ice in its polar regions and water vapors in the planet's thin atmosphere.
NASA's Phoenix module also registered snow and, possibly, water droplets falling in 2008. There are also hints that small amounts of liquid water could temporary build up in a thin layer below the Mars' surface.
The latest find, however, relies on radar information gathered by the Mars Express mission by the European Space Agency (ESA). The data shows a region of a uniform radar signature close to the south pole of Mars, which the Italian researchers claim to be a hidden lake.
Read more: NASA finds first evidence of liquid water on Mars
A total of 29 sets of radar samplings showed a "very sharp change in its associated radar signal," allowing scientists to map the outlines of the lake.
"The radar profile of this area is similar to that of lakes of liquid water found beneath the Antarctic and Greenland ice sheets on Earth, suggesting that there is a subglacial lake at this location on Mars," said the report.
Too cold for a swim
Scientists believe the lake consists of liquid water, despite having an estimated temperature of –68 degrees Celsius (-90.4 Fahrenheit). This is possible if the lake has a large content of salt which significantly changes the freezing point.
The team lead by Orosei now speculates about the presence of life in the lake, comparing to similar locations on Earth, which are found below Antarctic and Greenland. Researchers have found life in an underground lake in the Arctic, dubbed Lake Whillands, but only on microbe-level.
Separately, NASA's Curiosity rover found "organic materials" on Mars last month. While the presence of organic molecules does not prove life, it points towards a "habitable environment" on the neighboring planet.
Currently, NASA is working on a mission to send humans to an asteroid near Mars in 2025 and land a human team on the planet sometime in the 2030s.
dj/rt (dpa)