Excited scientists reveal Martian flows
“There is liquid water today on the surface of Mars,” came the announcement overnight from Michael Meyer, the lead scientist on NASA’s Mars exploration programme.
It means Mars has even more of the conditions that are known to have existed in Earth around the time life first emerged. It adds weight to the idea that life could be almost anywhere in space, and advances the search for it.
The water flows could point space agencies towards exciting new landing spots for future human missions.
“Mars is not the dry, arid planet that we thought of in the past,” said NASA’s Jim Green.
“Liquid water has been found on Mars.”
The finding was not entirely unexpected in scientific circles, after pictures beamed back to Earth from Mars missions in the 1970s showed a surface of dried-up rivers and vast ancient lakes.
In March this year, NASA unveiled evidence of an ocean they say once covered half of the planet’s northern hemisphere.
The latest finding builds on evidence uncovered in 2011, when the high-resolution camera on NASA’s Mars Reconnaissance Orbiter captured what appeared to be small streams of flowing down crater walls from late spring to early autumn.
At the time, mission scientists named the flows “recurring slope lineae” or RSL.
The Mars Reconnaissance Orbiter has been used to analyse the chemistry of the mysterious RSL flows, with a spectrometer to look at infrared light reflected off steep rocky walls when the dark streaks began to appear at the beginning of the Martian summer.
The team says it found infra-red signatures for hydrated salts when the dark flows were present, which were not there before they had grown.
They say the hydrated salts – a mix of chlorates and perchlorates – are a clear indicator of the presence of water at the four sites inspected: the Hale, Palikir and Horowitz craters, and Coprates Chasma – a massive canyon.
“The mystery has been, what is permitting this flow? Presumably water, but until now, there has been no spectral signature,” Meyer said.
“From this, we conclude that the RSL are generated by water interacting with perchlorates, forming a brine that flows downhill.”
“These may be the best places to search for extant life near the surface of Mars,” said Alfred McEwen, a planetary geologist and senior author on the study.
“While it would be very important to find evidence of ancient life, it would be difficult to understand the biology. Current life would be much more informative.”
While the stunning find has excited scientists worldwide, it could also bring some fresh concerns for space agencies.
The flows could help find water sources on Mars - prime spots for the hunt for life.
But space agencies are required to do everything they can to avoid contaminating other planets with microbes from Earth, which makes wet areas the most difficult to visit.
Still working from a distance, researchers trying to find out where the water comes from.
There are a number of solid theories, including the idea that porous rocks under the surface might hold frozen water that melts in the summer months.
Another possibility is that highly concentrated saline aquifers exist beneath the surface in the form of saturated volumes of gritty rock, not pools of water.
A third possibility, which many experts suggest is most likely, is that salts on the Martian surface draw in water from the atmosphere, which builds up until there is enough to run downhill. It is a process known as deliquescence, and it seen here on Earth at places like the Atacama desert, where damp patches form and allow microbes to live.
Get all the details in the full press conference below.