Scientists at JPL say that new analysis of pictures taken on Mars contains the "strongest indication" that there is water flowing on the red planet, right now.

Top Image: Darkening lines (known as RSL) moving down a slope as the temperature rises, possibly representing spring and summer salt water flows on Mars, NASA/JPL


Researchers have long theorized that Mars had at one point held flowing water, and probably even held frozen water still. But, the presence of darkening lines moving downwards along a slope as the temperatures rise in the warmer months, suggests that there could be water flowing even now — and also suggests a mechanism for how it might be able to do it.

So, how does water flow in the frigid Martian temperatures that are present, even in the summer months? Researchers think that there may be a naturally-occurring anti-freeze in the water, caused by the high-iron content, which they were able observe by layering mineral maps over the area where the flows seemed to be happening:

Image: seasonal flows map of Mars, overlaid with a mineral-mapping spectrometer, giving a clue to the ferric iron concentrations in the area. / Lujendra Ojba, NASA/JPL



These mineral maps suggest that not only do the darkening lines represent an actual flow of water, presumably with a diminished freezing point, but also that the water and ferric iron flowed together as part of a brine.

So how certain are researchers that what they're seeing is really water flowing? Not 100% certain yet — but they're pretty close. "We still don't have a smoking gun for existence of water in RSL,"Lujendra Ojha, a grad student at the Georgia Institute of Technology and the lead author of new studies in a statement. "Although we're not sure how this process would take place without water."