Author Topic: NASA: Salty Water FLOWS on Mars TODAY, HIGH Odds for Life on MARS  (Read 2052 times)

0 Members and 1 Guest are viewing this topic.

Offline Mister Toast

  • Administrator
  • *****
  • Posts: 67
NASA: Salty Water FLOWS on Mars TODAY, HIGH Odds for Life on MARS
« on: September 28, 2015, 18:21:37 PM »
NASA: Salty Water FLOWS on Mars TODAY, HIGH Odds for Life on MARS

Text "Liquid water flows on Mars today, boosting the odds that life could exist on the Red Planet, a new study suggests.The enigmatic dark streaks on Mars — called recurring slope lineae (RSL) — that appear seasonally on steep, relatively warm Martian slopes are likely caused by salty liquid water, researchers said."Liquid water is a key requirement for life on Earth," study lead author Lujendra Ojha, of the Georgia Institute of Technology in Atlanta, told via email. "The presence of liquid water on Mars' present-day surface therefore points to environment that are more habitable than previously thought."These dark, narrow, 100 meter-long streaks (called recurring slope lineae) are flowing downhill on Mars (see picture above), and are inferred to have been formed by contemporary flowing water. Recently, planetary scientists detected hydrated salts on these slopes at Hale crater, corroborating their original hypothesis that the streaks are indeed formed by liquid water. 

The blue color seen upslope of the dark streaks are thought not to be related to their formation, but instead are from the presence of the mineral pyroxene.RSL occur in many different locations on Mars, from equatorial regions up to the planet's middle latitudes. These streaks are just 1.6 feet to 16 feet (0.5 to 5 meters) wide, but they can extend for hundreds of meters downslope.RSL appear during warm weather but fade away when temperatures drop, leading many researchers to speculate that liquid water is involved in their formation. 

The new study, which was published online today (Sept. 28) in the journal Nature Geoscience, strongly supports that hypothesis, team members said.Hydrated salts precipitate from liquid water, so detecting them is a big deal — especially since circumstances make it unlikely that CRISM could spot RSL water directly. (CRISM observes the Red Planet at the driest time of the Martian day, about 3 p.m., when any liquid surface water would likely have evaporated, Ojha said.)Observations by NASA's Curiosity rover and other spacecraft have shown that, billions of years ago, the Red Planet was a relatively warm and wet world that could have supported microbial life, at least in some regions.

Mars is extremely cold and dry today, which is why the discovery of RSL sites has generated so much excitement over the past four years: The features point to the possibility that simple life-forms could exist on the planet's surface now.

But the new results don't imply that life thrives on Mars today, or even that this is a likely proposition, Ojha stressed. Perchlorate brines have a very low "water activity," he said, meaning that the water within them is not easily available for potential use by organisms."If RSL are perchlorate-saturated brines, then life as we know [it] on Earth could not survive in such low water activity," Ojha said