Curiosity Finds Evidence of Ancient Surface Water

An anonymous reader writes "Curiosity has wheeled its way over to the low point in Yellowknife Bay and has found veined rocks, evidence that water once percolated through this area. Scientists are excited because it is the first evidence of precipitation of minerals and water. There is also cross bedding that can be seen, thin layers of rocks oriented in different directions. The grains are apparently too coarse for the wind to have created, alluding to flowing water. Even with this discovery, much is still not known about Mars' past." Rather than quickly moving along to Mount Sharp as planned, they're going to spend some time drilling into the rock.

Comments

Re:Too course

[ColdWetDog]

IIRC from previous discussions, we're talking an order of magnitude in size between wind based fines and water modified particles. Also the structure tends to differ. Of course, the summary is light on specific details so if you really distrusted it, you could wait for the formal paper. But I'm inclined to believe that the rocket scientists over at JPL know what they are doing....

Rounded edge grains

[SternisheFan]

Some of the grains have "rounded edges", not sharp edges, very good 'evidence' Mars has had water in the past.

In a Jan. 15 press briefing, NASA's Mars Science Laboratory researchers showed close-up photographs of the shallow depression, dubbed Yellowknife Bay, where the rover is located, about 500 meters west of its landing site. High-resolution photos of sand and rocks taken by Curiosity show signs of the presence of water in the past. Individual grains of sand have rounded edges from being "knocked around, busted up by some process," said Aileen Yingst of the Planetary Science Institute in Tucson and deputy principal investigator for the Mars Science Lab. "Because they're relatively large on the sand size spectrum, [that] indicates water."

http://m.iwgov.com/264939/show/a1412b9dd084473569011d6612b77cf8/?

Re:How do they know water?

[vlm]

Your solvent was a trick question, because water and NH3 are both polar so there is at least some overlap in solubility. Also they dissolve ridiculously well in each other. If you spec'd liq methane or some weird liq fluorocarbon then there's practically no overlap given methane is non polar.

Anyway yeah its the solubility thing which is indirectly related to pH. Its not very hard on earth to figure out if something was sitting in a water tank or an ammonia tank same thing on mars.

Also temp and pressure. Maybe you could do something weird with NH3 at 10 bar and 500 deg that looks kinda like water related corrosion, but no one will believe that happened on martian surface.

Re:Too course

[sribe]

While rocket scientists likely have lots of education involving fluid dynamics, I doubt they specialized much in erosion.

WHAT THE FUCK? You seriously don't think NASA has geologists to study geology???