NASA's Mars rover Curiosity has provided evidence that there might be liquid water on the Red planets' surface.
The explanation could be that the substance perchlorate has been found in the soil, which lowers the freezing point so the water does not freeze into ice, but was liquid and present in very salty salt water - brine.
Observations by the Mars probe's stereo camera have previously shown areas characteristic of old riverbed with rounded pepples that clearly show that a long time ago there was flowing, running water with a depth of up to one meter.
Now the new close-up images taken by the rover all the way en route to Mount Sharp show that there are expanses of sedimentary deposits, lying as "plates" one above the other and leaning a bit toward Mount Sharp.
New calculations were based on more than a full Mars year of temperature and humidity measurements by Curiosity.
They indicated that conditions at the rover's near-equatorial location were favorable for small quantities of brine to form during some nights throughout the year, drying out again after sunrise. Conditions should be even more favorable at higher latitudes, where colder temperatures and more water vapor can result in higher relative humidity more often.
Even though liquid water has now been found, it was not likely that life will be found on Mars, as it's too dry, too cold and the cosmic radiation was so powerful that it penetrates at least one meter into the surface and kills all life.
The study is published in the scientific journal Nature.
