After a weekend of rampant speculation, NASA has confirmed our suspicions: There’s probably liquid water on Mars, today. The landmark finding makes the notion of life on the Red Planet all the more plausible.
“Water is essential to life as we know it,” the researchers behind the new study wrote. “The presence of liquid water on Mars today has astrobiological, geologic and hydrologic implications and may affect future human exploration.”
The research, led by geomorphologist Lujendra Ojha of Georgia Tech, utilises new data collected by the Mars Reconnaissance Orbiter to show evidence for recurrent seepage of liquid water along Martian crater walls.
Firstly, images collected by HiRISE camera show that recurrent slope lineae—flow paths on Martian slopes appear that are thought to be caused by liquid water—appear to be seasonal, fading when inactive and reappearing annually over multiple Martian years. These features alone suggest the presence of flowing water, but the clincher comes in the form of spectral data, collected by the Compact Reconnaissance Imaging Spectrometer on the Mars Reconnaissance Orbiter: Hydrated salts within the flow paths. These offer powerful evidence of evaporated brine, possibly from an underground reservoir.
“Something is hydrating these salts, and it appears to be these streaks that come and go with the seasons,” Ojha said in a statement. “This means the water on Mars is briny, rather than pure. It makes sense because salts lower the freezing point of water. Even if RSL are slightly underground, where it’s even colder than the surface temperature, the salts would keep the water in a liquid form and allow it to creep down Martian slopes.”
It’s well established that ancient Mars used to be a much warmer, wetter place. It might have even been covered by a global ocean. But for years, scientists have debated whether liquid water could exist on the frigid, dry Martian surface today. If liquid water were present on modern Mars, that would substantially bolster the case for microbial life.
NASA has been teasing us with this news since a press release last week said that the space agency would be announcing a ‘major science finding’ that solves a longstanding Martian mystery. The timing of the announcement was well calculated: With the opening of the NASA-endorsed feature film The Martian this week, NASA is doing everything in its power to drum up public excitement about a real mission to Mars in the 2030s.
And what’s more exciting than the prospect of alien microbes?