Enlarge (credit: NASA)
The evidence for liquid water on the surface of Mars in the distant past is strong, but a discovery a few years ago provided a glimmer of hope that the wet stuff might still be making occasional appearances on the Red Planet.
Fresh, dark streaks show up on steep slopes during the “warm” season, almost as if something wet is trickling downhill.
To some researchers, however, these “recurring slope lineae,” which are a few meters wide and a few hundred meters long, look more like downward slides of destabilized sediment.
The question is, what could destabilize the sediment? The presence of briny water? (Water has been detected as a component of some of the minerals present, at least.) Could the thawing of carbon dioxide ice play a role? There is debate about which of these explanations can work and where water could possibly be coming from.
A new study led by Frédéric Schmidt of the University of Paris-Sud throws out a possible alternative that doesn’t involve thawing anything.
If you’re holding out for water, you might consider that bad news, but it is at least a satisfyingly weird process.
Read 8 remaining paragraphs