Liquid Water On MARS!

[croxis]

http://www.badastronomy.com/bablog/2006/12/06/liquid-water-on-mars/

See link for pictures

Today at 10:00 a.m. Pacific time, NASA announced they had, at long last, found strong evidence of recent liquid water flows on Mars.

Observations from the Mars Global Surveyor (MGS) have revealed "recent activity" on the surface of the red planet; recent meaning in the past seven years. These changes include cratering from impacts (which is cool enough, and I’ll blog about those later), but also, yes, the flow of water.

Years ago, there were gullies seen on slopes on Mars, and they looked a lot like water had formed them. But it was hard to tell. Now, the evidence is far stronger. For example, check out this image:

image of gully from water flow on Mars

This gully is in a crater in the Centauri Montes Region in the martian southern hemisphere. The critical piece of information here is that the gully did not exist in 1999, but is clear in 2005. It’s new!

In the higher resolution images (click it to see them) you can see the gully better. You can tell by eye it certainly looks like a liquid flow.

But how do we know they are water? The context is the key. Gullies indicate the flow of a liquid. Dust avalanches do occur on Mars, but not anywhere near these gullies. The morphology (shape) is important too. See how the gully breaks up as it flows down the slope? That also indicates a fluid flow. Finally, the color is an indicator, too. The light color is difficult to make on Mars. In trenches, most places where the surface dust is disturbed, and impact craters, the underlying layers are always dark. This indicates a different process. Also, numerical calculations using models indicate that whatever caused these gullies flowed like water, not like dust or rocks.

As they say on the Malin Space Science Systems website:

Of course, water was not the only fluid considered by various colleagues; carbon dioxide can be fluid at some pressures and temperatures, and fluid carbon dioxide was also proposed as a candidate fluidizing agent. Even dry mass movement—landsliding—of unconsolidated granular material can exhibit some fluid-like behavior, and such mass movements were considered as an explanation for the gullies.

The presence of channels, primarily formed by erosion—but also displaying features representing along-channel deposition, such as levees and meanders—and terminal depositional aprons consisting of dozens to hundreds of individual flow lobes, contributed to the general acceptance of the hypothesis that gullies involved the action of liquid water.

These bright features in the gullies might be frost, but they’ve been around a while, so that’s pretty unlikely. They might be salts and other minerals deposited by the flow, or they might be smaller sediments carried along with the water.

How much water are we talking about? Maybe 5-10 swimming pools’ worth according to Ken Edgett, the scientist who has been working on these data. It would be a pretty quick flash flood, and, weirdly, in the low atmospheric pressure, the water would be boiling even at the low temperatures of Mars.

So what does this mean? Well, we’ve known of frozen water on Mars for decades, and we know there was activity in the past. These new observations indicate that things are happening on Mars now, within the past few years. And whatever it is that’s happening, it’s releasing water onto the surface, which in turn means that there is water just below the surface of Mars, at least in some places.

Sounds like a good place to build a colony, don’t you think?

It does to me. If there are big deposits of water, then that makes it a lot easier for potential colonists to survive on Mars, "living off the land". While the amount of water in any one gully is small, it indicates more water is nearby. This is terribly exciting.

Now, the skeptic in me must say it: this is not absolute conclusive proof of water on Mars. We need better images (maybe from the new probe orbiting Mars now), and spectra would be nice (to be able to see what chemicals are there). Even better would be to land a rover near there to get samples, though gullies down the sides of crater walls would make a perilous journey for any robot.

If these aren’t water gullies, we’ll all be disappointed, but that’s science. They’ll still be interesting features! But the evidence is very, very compelling, and I certainly hope that NASA follow this up quickly with more observations.

Recent flow of water on Mars from subsurface deposits. Wow.

 

[bhsup]

Hey, what are those Martian polar caps composed of? Is it frozen water or some gas in a frozen state?

 

[croxis]

Combo of frozen water and frozen co2

 

[bhsup]

Hrm. With water frozen in the ice caps, I wonder if we could get a base going on the ice caps. Instant water supply and no dust storms to contend with, right? Might be a smidge chilly, though.

 

[brennan]

Frozen CO2 IIRC

 

[croxis]

Actually i think you are right in that it is mostly co2.

 

[Neomega]

Hrm. With water frozen in the ice caps, I wonder if we could get a base going on the ice caps. Instant water supply and no dust storms to contend with, right? Might be a smidge chilly, though.

Yeah, Mars is cold enough as it is on the equator.

but this is exciting... now they need ot find evidence of heat on mars..

 

[El_Machinae]

Doesn't it have a magnetic field?
I might be off-base, but doesn't that mean a molten core?

... (a moment on Google): it's theorised to have had a liquid core long ago, and we're merely seeing remnants.

 

[croxis]

Yah, there is no planetary magnetic field, just reminents of one. One idea is mars had a much thicker atmosphere, but the loss of the magnetic field caused solar winds to blow it away.

 

[Xanikk999]

I heard it can get above freezing on the equator of mars during the right time of the year.

Is this true?

So does that mean a person could run naked on mars with an oxygen tank?

 

[Serutan]

No. They'd get French fried by UV, because although
Mars gets less sunlight than Earth, none of the UV is
blocked on Mars.

 

[Shawnosaurus]

I am fascinated by Mars and even the announcements of a planned moon base. However, I am always frustrated by the slow pace which all this has to move at. I'm not getting any younger and I want to set foot on some other planet in my lifetime. This is of course very unlikely, but a guy can dream.

Kudos to the folks who have the skills to work in this field

 

[Esckey]

And theres the lack of air pressure too. If Water would be boiling in minus what ever(think -120c) then I can't imagine what that would do to your body.


I saw recently on TV that someone at JPL or NASA are purposeing that they put a a reflective satilite into orbit(made out of that solar sail stuff) and direct sunlight to a future manned landing site. Could heat it to +20C

 

[El_Machinae]

I am fascinated by Mars and even the announcements of a planned moon base. However, I am always frustrated by the slow pace which all this has to move at. I'm not getting any younger and I want to set foot on some other planet in my lifetime. This is of course very unlikely, but a guy can dream.

The secret, then, is to live longer.

 

[betazed]

The secret, then, is to live longer.

Which may be easier than we thought.

 

[Bluemofia]

I heard it can get above freezing on the equator of mars during the right time of the year.

Is this true?

So does that mean a person could run naked on mars with an oxygen tank?

You would also depressurize. It's Atmospheric pressure is tiny.

 

[Xanikk999]

You would also depressurize. It's Atmospheric pressure is tiny.

Could you describe a person depressurizing. Ive never seen it happen to be honest.

 

[Bluemofia]

Oh, the bodies explode.

Such as what soldiers observed in the American Civil war with bodies laying out in the Southern sun for too long.

And I don't think many people see bodies exploding on a day to day basis.

 

[Falcon02]

Actually the bodies don't explode.... as I've heard a story from my Prof. of a guy who was working in a Vaccum chamber and accidentally pulled his air hose out of the wall (thus causing him to depressurize).

He survived.

On a side note apparently here's what went through his mind.
"Oh ****!"
"Cool, I can feel the saliva boiling on my tounge!"
at that point he passed out.

Not that being in a depressurized environment would be good for ya.... in fact long term exposure is probobly deadly. But short term you should be okay, even if it won't be "enjoyable."

 

[Ansar]

What's a depressurized chamber?

And how could his saliva be boiling on his tounge?