It takes the form of brine flows along the Martian craters and canyons. These dark cast were known for some years, they came and went with the seasons, we do not understand well the cause. A “mystery Martian ” finally resolved, it is water which moistens a substrate made of chlorate and perchlorate magnesium and sodium perchlorate. In short, it darkens, which betrays the presence of liquid water, a bit like a concrete slab would be watered.
An index of life?
We already knew there was water on the Martian surface, but the form of ice at the poles. The presence of liquid water, if it were considered, is a real discovery. Consequently, can it be the source of life? A priori, no. These brines chlorate would not be viable for organizations, depending on what is known about terrestrial biology. Even if it does not stop surprising us with its versatility, notably the so-called extremophiles, organisms which, as their name suggests, are surviving in hostile places so that scientists do not understand how.
However, it must be that this water come from somewhere. There is two ways: up or down. The Martian atmosphere is too dry and thirsty to be the source of this water, though the exact composition of the lower Martian atmosphere is still to be clarified. A phenomenon as simple as the morning dew is not excluded. But the most likely hypothesis is that of the soil.
We have strong reasons to think that in its past, Mars was very wet, with oceans and rivers. Today, this water is evaporated into space or turned into ice at the poles. However, it is not inconceivable that the Martian subsurface always contains underground water pockets, a bit like terrestrial groundwater.
This is as many tracks to explore. The rover Curiosity NASA is now in what is called the Gale Crater, near one of these flows. Unfortunately, it has not been adequately sterilized: NASA feared he could embark with him terrestrial microbes that could contaminate the site. This raises the question of whether to deviate from the course to go see a little more closely. “ The matter is still under discussion ,” says Catharine Conley, who advocate global Nasa. His job is to ensure that objects sent from Earth to other worlds do not contaminate.
Finally, there is the next mission of the European Space Agency to the red planet . Named ExoMars, it will send a rover equipped with a drill two meters long to the Martian surface. Launch planned in 2018.
Timeline and key figures