Scientists have found evidence of briny water flowing on Mars during summertime on the Red Planet
Water exists in liquid form on the surface of Mars, Nasa scientists have said, making it possible for life to be sustained on the Red Planet.
Nasa hailed the “strongest evidence yet” of intermittent flows of briny water on Mars after scientists identified hydrated salts in dark streaks that ebb and flow down the planet’s slopes.
The dark marks, which appear in summer months, are thought to be caused by the salty water wicking up from a shallow flow beneath the surface – although the origins of the briny flows remain a mystery.
The water appears to exist in the form of “thin layers of wet soil", rather than pools of standing water, Alfred McEwen of the University of Arizona, one of the scientists who made the finding using new imaging techniques said.
The discovery of liquid water means Mars is “not the dry, arid planet that we thought of in the past”, Jim Green, Nasa’s director of planetary science said.
Crucially, it “suggests that it would be possible for there to be life today on Mars”, John Grunsfeld, Nasa's science mission chief, said.
Water is essential to life as we know it on Earth – and on Earth, wherever there is water there is also life, the scientists said.
However, it is not yet known whether the briny water discovered on Mars may be too salty to support terrestrial life forms.
Although microbes do exist in salty habitats on the Atacama Desert in South America, the most likely location for microbes on Mars would be in fresh water that scientists believe might exist deeper beneath the surface of the planet, scientists suggested.
Dr McEwen said he believed that “the possibility of life in the interior of Mars has always been very high” and it was “very likely” that there was life in the form of microbes “somewhere in the crust of Mars”.
Dr Grunsfeld said the briny water discovered on Mars could also be “useful to future travellers”, not only for hydration but potentially even for growing crops in “inflatable greenhouses”.
Nasa has already said it wants to put men on Mars and Dr Grunsfeld said he hoped Nasa would be able to do so “in the near future”. Any Mars mission by Nasa would cost tens of billions of dollars.
Michael Meyer, lead scientist for Nasa’s Mars Exploration Program said: “Now we know there is liquid water on the surface of this cold, desert planet. It seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”
The scientific paper behind the announcement, published in the journal Nature Geoscience, stopped short of claiming definitive proof of water but said the salt findings “strongly support the hypothesis”.
It suggested possible origins of the water could include melting ice, an underground aquifer or water vapor from the thin Martian atmosphere, although it also set out shortcomings with each of the possible explanations.
Cynics questioned the timing of Nasa’s announcement, which coincides with the launch of the Ridley Scott film The Martian, starring Matt Damon, which Nasa has assisted in promoting.
