Data from a NASA spacecraft showing flowing water on Mars has raised hopes that the planet could be capable of supporting life.
The discovery of the water flows was made after scientists developed a new technique to analyse chemical maps of the surface of Mars obtained by NASA's Mars Reconnaissance Orbiter spacecraft.
While the source and chemistry of the water are currently unknown, scientists believe that it could point to the existence of microbial life beneath the planet’s radiation-blasted surface.
Discussing the new study, NASA science administrator John Grunsfeld said: "It suggests that it would be possible for life to be on Mars today."
"If I were a microbe on Mars, I would probably not live near one of these [sites]. I would want to live further north or south, quite far under the surface and where there's more of a freshwater glacier. We only suspect those places exist and we have some scientific evidence that they do," he said.
When analysing the data, NASA found fingerprints of salts that form only in the presence of water in narrow channels cut into cliff walls throughout the planet's equatorial region.
Scientists suspected the streaks, known as recurring slope lineae, were cut by flowing water, but previously had been unable to make the measurements.
The slopes were first reported in 2011 and appear during the warm summer months on Mars, then vanish when the temperatures drop.
Mars Reconnaissance Orbiter makes its measurements during the hottest part of the Martian day, so NASA believed any traces of water would have evaporated.
The scientists on the study created a computer program that could scrutinise individual pixels which was then compared with high-resolution images of the streaks.
Concentrating on the widest streaks, which are typically less than five meters wide, they discovered a 100 per cent match between their locations and detections of hydrated salts.
"Mars is not the dry, arid planet that we thought of in the past. Under certain circumstances, liquid water has been found on Mars," said Jim Green, NASA’s planetary science director.
The study has raised further questions about the origin of the water. It is still unknown whether minerals in the ground are absorbing water vapour directly from Mars' thin atmosphere, or if there is a source of melting ice beneath the surface.
However, the prospect of water, even that which is laced with chemicals and salt, has implications for future human missions to Mars. NASA's current goal is to land U.S. astronauts on Mars in the mid-2030s.
"Mars has resources that are useful to future travellers," Grunsfeld said. "The water is really crucial because we need water to drink."
Flowing water on Mars infographic