By Casey Frye, CCNN Writer
In the year 2011, scientists discovered strange dark streaks on Mars that they called recurring slope lineae (RSL). They weren’t sure where the lines were coming from, only that they appear during warm martian seasons. Since then, a number of studies began finding evidence that the lines may in fact be water! Now, NASA has definitively confirmed that liquid water flows on the surface of the Red Planet.
According to a publication last year, certain features of the RSLs provide clues for the existence of Martian water. Scientists analyzed areas with RSLs and found they were more likely to have traces of certain minerals and chemicals when compared to regions that don’t have them. This didn’t necessarily prove water exists, but researchers pointed out that the process would be difficult to explain without the presence of water.
See, when it comes to the mysteries of space, scientists often use what’s not there to define what is there. It’s kind of like how your bedroom isn’t just defined by the walls, but by the empty space between them.
So, how did NASA jump from an educated guess to scientific certainty? Well, their Mars Reconnaissance Orbiter spacecraft analyzed the chemistry in the bizarre dark streaks, and confirmed they are formed by salty water flowing downhill. Since water is a basic building block of life, it could mean that tiny little bacterial aliens live on the Red Planet!
Images courtesy of Georgia Institute of Technology.