Mars may be wetter than we thought (but still not that habitable)

[Judi Lynn]

By Mike Wall 7 hours ago

40% of the Martian surface may support liquid brines seasonally — but they're extremely cold.



The dark streaks on some Martian slopes known as recurring slope lineae — imaged here by NASA’s Mars Reconnaissance Orbiter — may be caused by salty liquid water, some scientists think.
(Image: © NASA/JPL-Caltech/Univ. of Arizona )

Mars is wetter than previously thought, but not in a way that boosts its life-hosting potential, a new study suggests.

Liquid fresh water can't exist for long on the frigid Martian surface; the stuff quickly freezes or boils away into the planet's thin atmosphere. But brines — supersalty water — have much lower freezing points and can persist in liquid form on the Red Planet for longer stretches.

Scientists have seen possible evidence of such liquid brines over the years in the form of dark streaks on warm Red Planet slopes imaged by NASA's Mars Reconnaissance Orbiter. (Not everyone is convinced that liquid water is involved in the formation of these "recurring slope lineae," however.)

In the new study, researchers used measurements gathered by Mars-studying spacecraft and information from atmospheric models to devise a new model, which predicts where liquid brines could exist at and near the Martian surface.

More:
https://www.space.com/mars-wetter-than-thought-brines.html