It's official. On Monday morning, NASA scientists announced they have confirmed there is liquid water on Mars.
The space agency had said there would be a press conference to announce a "major scientific mystery" on Friday, but didn't elaborate on what sort of discovery the scientists had made. However, within hours, the liquid-water-on-Mars theory was bouncing around the interwebs.
NASA confirmed this on Monday in an announcement that was broadcast on NASA TV and on the space agency's website. NASA scientists used an imaging spectrometer (a device that provides 3-D representation of data) on NASA's Mars Reconnaissance Orbiter to spot what creates the dark streaks that would routinely disappear and reappear on the Martian slopes. The scientists discovered that the dark streaks are caused by briny water flowing across the slopes every so often. The streaks of salty water darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit, and disappear at colder times. (The salt in the water is key because without it, Mars is so cold that the water would freeze.)
The announcement is tied to a paper that has just been released in which NASA scientists confirm the streaks are caused by briny water. Lujendra Ojha, the lead author of the paper, came across the streaks when he was studying at the University of Arizona in 2010. Mars Reconnaissance Orbiter chief Alfred McEwen co-authored the paper, along with NASA researcher Mary Beth Wilhelm and five other scientists. "When most people talk about water on Mars, they're usually talking about ancient water or frozen water," Ojha stated. "Now we know there’s more to the story."
For years scientists and other space aficionados have theorized that these dark streaks that appear on the slopes of Mars were possible signs of some sort of water. We've known for a while now that Mars probably has water locked in its polar ice caps, and scientists have long believed that Mars was once a very wet planet with lots of water before it all escaped into space, but the discovery of liquid water on Mars is a huge deal because flowing water indicates that there has been or could be life on the planet. (The fundamental requirements to support life as we know it are liquid water, organic compounds and an energy source for synthesizing complex organic molecules.)
And now that we know about the liquid water, maybe the next discovery will be proof of life. But keep in mind, this didn't exactly happen overnight. “It took multiple spacecraft over several years to solve this mystery, and now we know there is liquid water on the surface of this cold desert planet,” Michael Meyer, lead scientist for NASA’s Mars Exploration Program, said. “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.”