a wide lake of underground liquid water discovered

Through an article published this week in the American journal Science a group of Italian scientists has just announced the potentially historical discovery, thanks to the Mars Express probe, of a large volume of liquid water on the planet Mars.
                

The south pole of Mars. (credit: European Space Agency)

The discovery is based on radar surveys of the Mars Express spacecraft, launched in 2003 by the European Space Agency (ESA), between May 2012 and December 2015. These reveal, under the south pole of the red planet, an anomaly which, by elimination, could only be interpreted as a vast body of liquid water by the Italian authors of the study. Concretely, this water has not been seen, but the data leaves as it stands a single explanation: a lake 20 kilometers wide hides 1.5 km below the icy surface of the pole. Given his situation, his temperature is probably negative. The presence of salts and minerals, however, should prevent frost.

The question of life on Mars revived

Besides the presence of this precious resource for future missions, this discovery is particularly significant for research on a hypothetical life on Mars. On Earth, bacteria survive in the inhospitable regions of the poles. It is therefore not forbidden to think that a similar form of life could have developed elsewhere. In this case, the conditions seem extreme to really believe. But nothing says that this polar lake is the only shelter below the surface of the planet. Significantly warmer regions could also surprise us, especially since phenomena resembling occasional runoff have been observed in the past.

Moreover, even if it turns out that Mars is currently not in any shape of life, it does not mean that it has always been so. Several billion years ago, the environment on the red planet was indeed much more welcoming, including a vast ocean. If we have not survived to this day, the hypothetical Martian life could have died out only much later, falling back on the last pockets of water – in which case, it is perhaps precisely there, in or near these pockets, that any traces of life could still be found.

However, it will take patience to see before a mission dedicated to the exploration of these underground areas. Meanwhile, two rovers are expected to land on Mars in 2020 to explore the surface a bit: one as part of NASA's March 2020 mission and one as part of the ExoMars program of the ESA, in which his Russian counterpart also takes part