NASA has announced evidence of flowing water on Mars, a finding which could have major implications for the chance of discovering life on the planet.
The agency said that streaks observed on the surface of the Red Planet were likely caused by water flowing across or just beneath ground.
The streaks, known as Recurring Slope Lineae (RSL), run hundreds of metres long in places and are the first evidence of their kind ever found on another planet.
Jim Green, Director of Planetary Science at NASA said during a press conference on Monday that “under certain circumstances, liquid water has been found on Mars”.
“Our rover’s finding a lot more humidity in the air than we ever imagined. As we inject the soils, they’re moist, they’re hydrated, full of water,” he said at a press conference.
“These discoveries are very important, but only part of the hydrological cycle on Mars that we are just now beginning to understand. What we are going to announce today is Mars is not the dry planet that we thought of in the past.
“Today we are going to announce that that under certain circumstances liquid water has been found on Mars.”
It is not yet clear where the water comes from, with scientists speculating that it may rise up from underground ice or condense out of the planet’s thin atmosphere.
The discovery was made after using an imager on NASA’s Mars Reconnaissance Orbiter to examine light waves returned from the RSLs.
Analysis revealed the streaks absorbed light at specific wavelengths connected with chemicals known to pull water from the atmosphere.
Since water is essential for life, the discovery increases the possibility of finding life on Mars, NASA said.
Alfred McEwen, principal investigator for the High Resolution Imaging Science Experiment (HiRISE) at the University of Arizona in Tucson, told the press conference at James Webb Auditorium in Nasa Headquarters, Washington, that he thinks the chances of microbial life on Mars is very high.
The latest findings, published in the journal Nature Geoscience, confirmed earlier reports by scientists about the RSLs, with NASA saying the flowing streams of salty water flow down certain Martian slopes each summer.
These dark, narrow streaks tend to appear and grow during the warmest Martian months, and fade the rest of the year. Salt lowers the freezing point of water, and scientists say that would explain these seasonal briny flows. Similar streaks to those being seen on Mars can be found in Antarctica.
Mary Beth Wilhelm of NASA’s Ames Research Centre in Moffett Field, California said these RSLs have been found in many locations.
“These vital perchlorates have been found at many of the landing sites on Mars. They may be more widespread than first thought,” she said.
John Grunsfield, Associate Administrator for NASA’s Science Mission Directorate, said the discovery could prove significant ahead of future manned missions to the planet that will “explore the question of whether there’s current life on Mars”.
There are three unmanned spacecraft planned to go to Mars in the coming three years, at least one of which — the European Space Agency’s ExoMars rover — will drill into the surface to look for evidence of life.
Ice was already known to exist on the Red Planet but the possibility of flowing water was first suggested in 2011 by a 21-year-old American PhD student, Lujendra Ojha.
According to a CNN report, Mr Ojha was studying at the University of Arizona when he used a computer algorithm to remove visual distortions from images of Mars obtained by satellite.
While Mr Ojha was comparing changes to the planet over time, he accidentally discovered irregular streaks appearing and disappearing on the surface of Mars.
After months of research, Mr Ojha concluded the streaks were likely dried salts left by salt water running on the surface of Mars during the warmer months.
The researchers say further exploration is warranted to determine whether any microscopic life might exist on modern-day Mars. They based their findings on data from NASA’s Mars Reconnaissance Orbiter, which has been circling Mars since 2006.
NASA’s announcement prompted a flurry of excitement on social media, with some Twitter users determined to see the funny side.