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Water Ice On Mars
cathector sends along a story from SpaceWeather.com on the discovery of water ice on Mars.
"Scientists have figured out the mysterious white substance unearthed by NASA's Phoenix lander on Mars. It's frozen water. The breakthrough came last week when Phoenix's stereo camera caught the substance in the act of disappearing. Bathed in martian sunlight for four days, the white substance sublimated — i.e., it transformed from solid to gas without passing through the liquid state. This is how water behaves on Mars.... Some readers have asked, how do we know the white substance is not frozen CO2 (dry ice) instead of frozen water? Answer: Phoenix's landing site is too warm for dry ice. The average daily temperature is about -70 F while dry ice requires temperatures lower than about -109 F." The animated GIF showing the ice sublimating is pretty nice too.
Now we just need a little global warming.
In other news, NASA announced today that a manned mission to Mars is planned to retreive the newly found ice in time for the 2012 Kentucky Derby. NASA plans to upstage Woodford Reserve's famous $1000 Mint Julep at the race with its own $3,000,000 version of the traditional cocktail. While plans are still being firmed up, the beverage will reportedly come in a limited edition collector's glass.
Pardon my total ignorance of the subject, but does this mean that it might occasionally snow on mars? Or would the environment be too different to allow it?
Everything will be taken away from you.
http://science.slashdot.org/article.pl?sid=08/06/20/026241
First against the wall when the revolution comes
If I remember my chemistry classes correctly (there is a high chance I don't), water would do this under lower air pressure, I think. Correct me if I'm wrong, I just thought some kind of explanation would be better than "because it's on Mars".
Admit it. You post strawman arguments as AC so you get modded Insightful for refuting them, rather than Troll
That animation is actually cut off. The main sublimation that was observed is below the frame of that picture. There's a better one here, where you can actually see the small chunks farther down disappearing completely.
It means we finally have a suitable accompaniment for Martian scotch.
You're absolutelly right, all we need now is some Martian Whisky and the social lives of any future human expedition is well and truly sorted out.
A learning experience is one of those things that say, 'You know that thing you just did? Don't do that.' - D. Adams
And why are we using F? This is a science article, posted on a web site for nerds.
I've noticed that almost all of the news headlines covering this are qualified statements like "Lander finds water on Mars, according to scientists". As if they're afraid to actually say something straightforward like "Water found on Mars" and they have to make it clear that they're just reporting what someone else is saying (with the implication that maybe they don't really believe it). At the same time they seem to have no problem with other headlines like "Celebrity Arrested Drunk" without the need to qualify it as "Celebrity Arrested Drunk According To Police" etc.
Maybe it's just me, but I mind it a bit irksome that so many big news outlets seem so detached from any sort of science reporting these days.
G.
It was at the bottom of a trench. Plus, wind doesn't selecticely blow white rocks away while letting the rest of the scene untouched. Plus, you can also see some white areas at the end of the trench getting smaller.
It's ice. Definitely.
"It's too bad that stupidity isn't painful." - Anton LaVey
Could we have this important information in units used by, I don't know, the rest of the world?
escape velocity on mars is 5.027 km/s, and water vapor will slowly move out of mars because of its high rms velocity. So, the answer is "no"
There is wind, however it apparently didn't move anything else in the pictures. Also, the wind wouldn't be very strong since the atmosphere is so thin.
Here's the problem: We still don't know conclusively. Yes, we have observations which are highly suggestive, but we don't have a chemical composition of the substance, so we don't know for sure.
Science is a hard mistress; she demands proof before making such claims.
Mod me down with all of your hatred and your journey towards the dark side will be complete!
Although I agree with you in principle, I think it might be due to the anticipation of NASA's announcement, which could do away with the "according to scientists [working on the project]" caveat.
News fails to take responsibility according to one internet poster.
More at 8.
Well, back to rejecting software patent applications.
Not only that, but Phoenix has a little weather station on board called the Telltale project. And if you look at this page you can see the weather reports for where Phoenix is on a sol by sol basis. None of them show windy conditions, although it looks like there is data missing for a few sols.
http://www.rootstrikers.org/
Finding water was one of the key goals of the Phoenix mission.
That is a bizarre statement. Large quantities of ice have been observed in numerous ways already. Even the Viking lander observed water frost directly in the 1970's:
http://en.wikipedia.org/wiki/Viking_2
http://www.solarviews.com/cap/mars/frost.htm
That frost sublimated just like this ice did.
Here are other observations:
http://science.nasa.gov/headlines/y2002/28may_marsice.htm
Here you can see a frozen crater lake:
http://esamultimedia.esa.int/images/marsexpress/210-010705-1343-6-co-01-CraterIce_H.jpg
http://www.esa.int/SPECIALS/Mars_Express/SEMGKA808BE_0.html
Not only is that ice, it may actually be an outflow.
What makes the results from Phoenix exciting is that the actual experiments that Phoenix is supposed to perform depend on having landed on ice. But finding ice somewhere on Mars is not a surprise.
It's 1% of Earth's atmospheric pressure. At that point there is no water, only solid and gas. And the sublimation point is a lot lower because of the lower pressure. (Less pressure = less molecules keeping the other molecules tightly packed)
True, wind doesn't selectively blow white rocks.
But it would selectively blow an ultrafine powder which happened to be white.
We could always just ship the abundance of water we have to Mars. Oh, wait, that's 10 years from now when politicians can't deny global warming any longer and they'll need some other boneheaded assumption to go on like water not being all that heavy to launch into space. The shit practically lifts itself!
"Most people, I think, don't even know what a rootkit is, so why should they care about it?"
OK, we admit it - none of the NASA scientists are as smart as you are, the whole "powder" thing just never occurred to them. Doh!
This space available.
Do it yourself, because no one else will do it yourself. [beta blockade 10-17 Feb]
How much water have you found on Mars?
Uh-huh. I thought so...
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
They haven't run the tests yet. This is just something they noticed when they landed.
We send this probe up there with all this fancy testing equipment, only to land in the friggin' stuff we're trying to find. It's actually pretty funny...
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
Actually, that argument can be made for any atmospheric gas constituent, not just water vapor.
There is less water in the Martian atmosphere oxygen while the water is more massive, so the oxygen would leave at a proportionally greater rate (assuming we are observing a long term steady state). One theory of the rapid loss has more to do with disassociation of H and O by UV radiation. H would quickly leave by your molecular motion argument leaving a relatively larger amount of O.
If that's the case, we'd be much better off leaving it subsurface for life sustaining purposes - sublimed ice is lost water. Now, we could use a bunch of nukes to lift dust to the increase greenhouse effect ... :)
The little guy just ain't getting it, is he?
First, I think the best evidence so far that this is water is not this picture, but the fact that the Mars Orbiter's spectrometer determined that that is was a lot of hydrogen in the ground near the poles.
That some white stuff vanishes is poor evidence. They need to get the white stuff in an oven and test it.
Let's assume it is water.
What really puzzles me is how clean the water is. It is covered with what would make a dirty mud if it ever melted together. Also on earth, you never have clean water if you have flash floods like what you see as a result of a volcanic eruption or meteroid impact. You only have clean water/ice in snow and still lakes/oceans.
This implies:
1. The ice has not melted after the dust blew over it.(A long time)
2. It used to be a lake/ocean or snow
So the purity of the ice might be a bigger discovery than the fact that it is ice there.
don't cut it off www.mgmbill.org
Yep, Vodka.
Here
How to read them
I feel that a great disservice was done to a lot of us early on with a simplistic view of the usual three phases of matter.
And yes, you're right. That is part of the explanation.
Perhaps next mission they should take along some sugar. Put it out and see if it 'sublimates' as well.
Memo to all Enforcers:By order of the Council of Elders, anyone caught consuming the sweet, sweet bait near the robotic invader from the blue planet is to have his gelsacs summarily pierced.
Signed,
K'Breel
There's a perfect xkcd for my sig but I'm too lazy to look it up. sudo someone go find it.
> Hopefully they are right about it.
Of course they're right about it, they have solid photographic evidence.
A similar experiment was recently conducted to determine the existence of life in Congress. A large pile of money was left sitting out which sublimated while votes accreted; thereby proving the existence of life in Congress. It is still up for debate how long before intelligent life is found in Congress.
A couple of 30-somethings embark on the ultimate roadtrip
But you're right, either way the dissociated hydrogen is way lighter.
a,e,i,o,u and sometimes w and y (at be if of up cwm by)
So these two frames were taken four days apart while the sublimation was taking place. My question would be - where are the rest of the frames? Does this lander really only "look around" every few days?
It would be nice to see it at even a 1-day resolution and get a 4-frame animation of the process. Those lumps should be seen to get smaller and vanish.
Not that I'm complaining, this is still very cool (no pun intended).
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
Yes, still not cold enough as far as I can tell given this phase diagram and these temperatures and pressures.
Were that I say, pancakes?
U.S needs to upgrade it's standards. A good start would to move from Fahrenheit to Celsius. After that you can move over to the metric system.
-70 F is -56 C
-109 F is -78 C
Conversion done with Google.
The AC is thinking critically, while you appeal to authority. Which type gets to work at NASA?
"A language that doesn't affect the way you think about programming, is not worth knowing" - Alan Perlis
You'd hope that after 300 or so years of chemistry we'd understand how to recognize water...
Actually I was just being snarky. I guess because I've been hanging around on Pharyngula and FSTDT a lot lately, dealing with the "evolution is just a theory!" and "particle physics proves astrology!" wackos.
This space available.
When I read that after several days they'd finally finished shaking a sample down into the oven, I though "well, I guess they're not looking for light organics suspended in water". I'd think they'd grab a chunk and get it in the oven quickly to detect all the organic chemicals, including the water-soluble light ones.
there's a number of geological processes that can concentrate water like this
in areas on earth where a lot of freezing and thawing occurs on earth, rocks get concentrated neatly in rings according to size, as if someone sorted them
i'm not saying this process is anything like why the ice is so pure on mars, what i am saying is that there are plenty of natural processes out there that concentrate materials in orders that, contraintuitively, seem like it took intelligent concentration, but are in fact totally natural
i won't even begin to speculate what processes on mars could do this, but i wouldn't be surprised if someone more knowledgeable than me could describe such a natural mechanism for ice purification on mars
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Neither, because NASA only hires smart people.
If you mod me Overrated, you are admitting that you have no penis.
That a lot of the people here see dry ice, white and solid like the stuff found on mars, and the fact that dry ice subliminates in our atmosphere, and come up with the idea that the white stuff must be solid CO2 and not water. Of course this is completely fallacious logic, as the pressure and temp in the area make it physicaly impossible for CO2 to be a solid (if temp/pressure data is correct)....
I've read Slashdot for the last 5 years, and now I start posting... Go figure
I thought this Wired quote about why the water sublimates on Mars is interesting:
"Just like dry ice does here on Earth, water ice goes from solid to gas when the pressure is below 6.1 millibars and it gets heated (like it does in the Martian sun). It can also go straight from solid to gas above 6.1 millibars when the vapor pressure (amount of water vapor in the air) is low enough. This is because the molecules of water in solid form and gas form are not at equilibrium."
http://blog.wired.com/wiredscience/2008/06/answering-mars.html
ZuluPad, the wiki notepad on crack
Are they sure it's NOT martian whiskey? ;) Or some sort of liquid that looks like water when frozen?
I'd go on a Vegan diet but the delivery time from Vega is too long. --brownkitty
PI'm just flabbergasted that the ice could exist so close to the surface without sublimating purely from solar warming of the soil.
The soil on Mars is cold enough (say -50 C) to keep ice from sublimating below a certain depth. From the pictures I would say that depth is 50-100 mm.http://michaelsmith.id.au
You say you think it's sublimation
Well you know
that'd be out of this world
What else could explain the diminution
Well you know
that'd be out of this world
But when you talk about reduction
Don't you know ice ain't the only thing
Don't you know other substances are white [x3]
You say you got an aqueous solution
Well you know
We'd all want to see the proof
Martians might be liliputian
Well you know
Look for them if you can can
But if you want money for space probes that crater
All I can tell you is brother maybe later
Learn how to use metrics first, alright? [x4]
Kwisatz Haderach
Sell the spice to CHOAM
This Mahdi took Shaddam's Throne
Scientist have believed the Martian polar cap are water ice since 2003: http://www.spacedaily.com/news/mars-water-science-03c.html
If I understand correctly, the water is blowing away.. just not as crystals. It is blowing away as discreet water molecules much like evaporation. The crystals gain energy from the sun and a little from the impact of the atmospheric gases and then the water molecules lift from the crystal lattice and suspend in the atmospheric gas matrix.
If you visualize everything as tiny versions of the colored balls in a child's play pit, you will notice that each type of ball (atom) has a different weight and tends to stratify. With enough energy added to the ball, it will then de-stratify and lift into the active matrix of the atmosphere.
Codifex Maximus ~ In search of... a shorter sig.
I would rather use the nukes to bring a few asteroids to impact mars. Some of those contain a load of ammonia. Ammonia is a great great house gas. Of course, that would disassociate over time, leaving N2 in the atmosphere.
I prefer the "u" in honour as it seems to be missing these days.
There is a fair bit of difference between believing and knowing!
You leave Mr. Stallman out of this!
Bot Assisted Blogging
You're right. Definitely photoshopped.
Truth arises more readily from error than from confusion. -Francis Bacon
Water freezes at zero degrees. :-p
But seriously, this is oversimplified. Water freezes at 0 degrees on Earth, at standard pressure. Furthermore, even when water freezes, there's still water vapor. Really, if you think about it, you can't have the physical states without multiple molecules. Liquids and solids require certain arrangements of multiple molecules. In either case, individual molecules can escape, thus sublimating. The energy from the sun was enough to cause these molecules to escape, even though the ambient temperature was below the melting point of water.
Really, the best way to think about the melting point and the boiling point is that the melting point is the lowest temperature at which liquid will exist, and the boiling point is the highest temperature at which liquid will exist. Gas can exist at all temperatures because gas is nothing more than molecules that have broken off from the liquid or solid.
Eventually, if you raise the temperature enough, no liquid or solid can form. Likewise, if you lower the temperature enough, eventually, no molecule can escape. This is why metal doesn't generally sublimate. The amount of energy needed is not provided by the temperatures commonly found on earth (metal can sublimate in other conditions).
And the smart thing for NASA to do these days when their budget is under constant pressure, would be to release spectacular, tabloidish news to raise interest in the agency. The whole water on Mars thing could thus very well be a publicity stunt, in lack of more solid evidence (after reading comments here, there seem to be such evidence, still, critical thinking is of the essence when it comes to NASA).
Don't be crazy anymore!
It took many days to determine that the white stuff Phoenix uncovered was ice (and not salt). An astronaut on Mars would have made that determination within seconds.
A-Bomb
Even Martian ice is melting. We are doomed.
After looking at that fascinating GIF from the summary, I'm not sure it is water. It just kind of disappears. It's probably some sort of highly advanced life form that can change its shape at will and lives beneath the planet's surface most of the time. It then just came up for a little Martian sunshine and, upon noticing our probe went back to tell its buddies that the Earthlings sent more crap to their planet and that they should expect an invasion soon. Unless they can prove to us they don't have any oil.
Well, that's what it looks like to me. Draw your own conclusions.
Saying "I'll probably get modded down for this" in a post is the best way to get it modded up.
If that -is- water in the white bands and not hardpan and a little seasonal frost, that might explain the darker areas within the streak - some localized melting in the sun.
It is true that the average daily high at this site at this point in time is -25*, but as anyone from northern States knows, surface temperature can be quite a bit higher than atmospheric temperature, and with the various salts we know are in the soil, the actual melting point can be below that daily average high. (Just as you have to walk through puddles to get to Stuffmart when it is that cold up here, because of all the salt they put down).
As to the probable frost in the soil, things like insulation from the sun (though at 1 inch depth, that wouldn't be much) tending the temp towards the daily average, isolation from the air (again, not much at that depth) and the added pressure of the soil bringing up the boiling point, could all be factors.
Personally, I don't think that they have ruled out that it -is- hardpan held together with either electrostatic force, or by a tiny amount of frost, which did then sublimate.
They say that Phoenix can't dig into the ice layer. Say -What-? Isn't that what they sent it to do? We really need to be willing to spend an extra 10 million per launch to use heavier lifters and more robust machinery! Very cost effective compared to what it costs to lighten and miniaturize things - just ask the Russians, they know this.
Does that make the robot less effective, or just slower?
By virtue of being slower, it is automatically also less effective, since it has a limited amount of time to operate.
Not necessarily - by not needing oxygen, and a way out, etc, it can prolong the stay. Maybe it can even more-than-compensate for its slowness.
So its not that clear-cut.