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Mars Canals May Not Mean Water
Ant writes "
NASA scientists are beginning to suspect
that the widely reported water channels on Mars were actually caused by
jets of carbon dioxide.
At a conference at NASA's Ames Research Center, NASA researcher
Robert Haberle said scientists now think Martian gullies believed to have
been carved by liquid water may instead have been produced by flutes of
liquid carbon dioxide, a finding that could have profound effects on future
missions to the Red Planet." This story has been bouncing around for a while.h
At standard atmospheric pressure, CO2 doesn't exist in a liquid state (hence "dry" ice, which goes directly from solid to gas). At other pressures, it can exist as a liquid. There have even been some experiments to use liquid CO2 as an environmentally-friendly dry-cleaning fluid.
I thought that when "they" reported that canals DO mean there was liquid water, "they" had carefully considered and ruled out other possibilities like CO2 jets.
I just *love* fundraisin^H^H^H^H^H^H^H^H^H^Hscience reporting.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
A mass of neutrons kept from collapsing only by neutron degeneracy? Seems pretty unlike regular matter to me.
This
link describes it in more detail.
It also lists some other exotic type matter speculated to be in neutron stars - pion condensates, lambda hyperons, delta isobars.
-- perl -e'print pack"H*","6e656d6f406d38792e6f7267"'
bose-einstein condensate
quark-gluon plasma
liquid metallic hydrogen (a superfluid sometimes counted as a seperate state)
neutronium
Of course, perhaps he is suggesting that the massive martian death-ray lasers carved the channels...
-- perl -e'print pack"H*","6e656d6f406d38792e6f7267"'
Nope, that was Lockheed Martin.
Next flaimebait.
Can someone point out Malin's explaination (serious not sarcastically) of how Mars had liquid CO2. We played with CO2 in my chemistry lab once and in the course of said playing we got it to enter the liquid phase. This only happens at 3.something atm and last time I checked Mars didn't have even 1 atm worth of troposphere. It would be literal jets that shot out of the ground but to me it seems unlikely that those jets would have the longevity to make some of the longer canals.
I'm a loner Dottie, a Rebel.
Stop bogarting the J, dude.
-B
I C Obfuscated C Lives.
If you're going to submit a story. At least have the decency to write your own blurb, and not simply copy and paste the blurb from Wired.
First, that's plagurism. Secondly, that's just lame.
The pressure of Earth's atmosphere is too low to permit liquid carbon dioxide -- that's why dry ice is, well, dry.
/.
/. If the government wants us to respect the law, it should set a better example.
Ok, IANAPhysicist (although I wanted to be ;), but would a large amount of carbon dioxide make feasible the possibility of creating an atmosphere on Mars? Or is the gravity just too low? I thought CO2, as it behaves here on earth in the green-house effect, can do the same in other environments, trapping humidity, heat, and other gasses. Is this right? If so, it would be cool if they just tapped the CO2 "wells" to create an instant atmosphere ;)
It's 10 PM. Do you know if you're un-American?
This is why they are the scientists, and you are not.
that depends entirely on the pressure. The lowest pressure that CO2 can exist as a liquid is 5.1 athmosphere, at a temperature of about -57C.
check out this diagram
//rdj
No one can understand the truth until he drinks of coffee's frothy goodness.
--Sheikh Abd-Al-Kadir, 1587
if CO2, like water, actually *expands* when going from liquid to solid. I thought water was somewhat unique in that aspect, tho'!
This property of water is due to hydrogen bonding, so it wouldn't occur in CO2.
Giant... Mars Worms!
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
I was wondering if someone else would've noticed that. I suppose a phase shift from solid to gaseous form could've occurred at lower pressure, causing the channels to form. But any article citing "liquid C02" should be viewed dubiously, at best.
CO2 can go from solid to gas at 1 atm (sealevel). At sealevel and above(lower pressure), CO2 only exists as a solid or gas. Mars does not have as heavy of an atmosphere as Earth, so my guess would be that it would only exist as a solid or gas on Mars. However, if you've ever seen DryIce (um, most mad scientists mix colored waters with pieces of CO2 together to get a highly explosive substance) you'll notice that, in our atmosphere, it sinks to the ground. It's very heavy and "flows" through the air like water. My guess is that it would emerge from the ground and "flow" along the dusty surface of Mars, causing "canals".
Oh, and CO2 will exist as a liquid. But only at higher pressures (~5.2 atm and up (5.2+x)) and certain temperatures. Here http://onsager.bd.psu.edu/~jir cit ano/phaseco2.jpg is what is called a phase diagram. If you want to read it, it would have to be marked. The "y" part would be in atm ("atmospheres" == pressure) and the "x" would be in temperature (deg C). Pick a pressure and temperature. find where the lines meet, if it's red, the substance would be a solid at that pressure and temperature. If it's blue, a liquid. Yellow, a gas. If you look, you'll see that for all temps at 1atm, CO2 will only exist as a gas or a solid. So, since Mars would have a much lower atmospheric pressure than earth, it's likely to only be found as a solid or gas on mars, too.
Actually, I found this http://www.timesofindia.com/04080 0/0 4hlth1.htm article with a search at Google. Neato!
Withdrawal before climax is very ineffective and those who try this are usually called "parents."
Due to the configuration of their orbits, and the fact that the Martian year is roughly twice that of Earth's, a launch window to Mars opens every two years. The actual trip takes around 6 months, one way. Thus, a typical manned mission would take 6 months getting to Mars, spend 18 months exploring the Martian surface while waiting for their return launch wind ow to open, and 6 months to travel back to Earth.
To email me,subtract my nick from my email address, starting with the second character. (hint: adto.uiuc.edu is wrong)
I thought that CO2 was one of those things that went from gas to solid... (sublimate? is that the word?)
Either way - it wouldn't be hot to get liquid CO2...
BlackNova Traders
Wow, those Martian pilots are talented, what with flying those jets of carbon dioxide (is that like carbon fiber?) and playing the flute and all....
--
As a matter of fact, I am a lawyer. But I play an actor on TV.
I doubt it: the features under discussion show typical mass wasting at the head of the formation, such as occurs when a spring undercuts the soil overlying the aquifer which feeds it. That, plus the delicacy of the features, argues strongly against them being formed underground and then being uncovered -- they're plainly erosion features, formed on the surface.
Further, some of these are very new features: they haven't been covered by the ubiquitous dust which generally blankets everything on the martian surface within a few years at most.
I can't figure out what the "liquid CO2" bit is all about; I suspect part of the explanation is missing from the popularization... I think I'll ask some of the folks doing the work.
---
---
Politics is about making compromises. Religion isn't. --Michael Horton
'Less money on talk': Talk? This is research into the results transmitted by the probes. Or do you propose sending probes, saying 'Hurray! They got there!' and then spending more money on more probes, without analysing the data?
It costs a fairly insane amount of money to send craft to other planets, even the closest one. You have to spend a lot of money on talk/research first, to figure out what you're going to equip the probe with, how it's going to get around, and so on and so on.
The approach of sending out hundreds of tiny autonomous probes plus a few 'base stations' to control them seems to be more appealing than the One Big Probe that they usually send; more scope for redundancy in case some of equipment failure, and the possibility of examining more of the surface.
The neat thing is that as soon as I saw you talk about liquid CO2 for dry cleaking, I was thinking of an ultra cooled liquid being used to wash my clothes, and thinking that "gosh, it must cost a lot to re-cool the CO2 after pouring it on all those room temperature clothes". Of course if you have enough pressure, you can have liquid CO2 at room temperature, which is just damn strange if I think about it. Warm liquid air? Ok, if you say so..
See the bottom of this for the phase diagram, which indicates that at room temperature you need 30 plus atmospheres of pressure, or more than 450 lbs per square inch.
Here is a demo/video of dry ice turning into liquid CO2! (get rid of the space after the L near the end of the URL. Sorry, the submission form is wrapping it.)
Ask A Scientist - Liquid CO2
Liquid Carbon Dioxide (CO2) Surfactant System For Garment Care
Why CO2 in Fire Suppression Systems
CO2 Snow Cleaning and what it's best used for.
I want to know how they know that liquid CO2 has a slightly acidic taste and odor!! Did they get inside a 30 atmosphere room temperature container with some liquid CO2 and take a taste?
And finally - test your knowledge of Liquid CO2
Comment removed based on user account deletion
I thought it was Venus that had the canals... What? That's Venice? My bad...
</stupid>
Free music from Jack Merlot.
"This story has been bouncing around for a while.h"
WOW!, i can't wait until i can see the while.c then!
I would have thought that the low pressure/temperature of the Martian atmosphere would cause most of the liquid CO2 to become gaseous and the rest to solidify into CO2 snow (dry ice).
If I remember correctly, this is how dry ice is made now. Cool CO2 enough that it becomes liquid, and then shoot it out into a lower pressure. The lower pressure makes most of it turn into a gas, but to get the thermal energy necessary to do that, it grabs heat from the rest, which solidifies.
Is there any evidence of a powdering of CO2 snow near those canals? Or were they formed long enough ago that any snow would have sublimed off into the atmosphere...
It may look like I'm doing nothing, but I'm actively waiting for my problems to go away.
--Scott Adams
What's important is not whether the canals were water.
We have plenty of evidence that water exists on Mars,
independent of whether the canals themselves were
caused by water (e.g. evidence from the polar ice-caps.
The presence of liquid CO2 on
Mars is almost as useful as We have plenty of
water would be, since liquid evidence that water
CO2 has so many industrial exists on Mars,
uses. The presence of the independent of whether
two together is good news to the canals themselves
this reader, I assure you. were caused by water
A planet with so much
geological activity in its history and potential for
terraforming won't be set back by a discovery such as
this.
-- Anne Marie
The triple point for carbon dioxide occurs at 5.11 atmospheres. Maybe there are underground CO2 "aquifers" on Mars, but these aren't underground channels we're talking about, they're surface features. For liquid CO2 to exist on the Martian surface, it would have to be sitting under over 50 meters of frozen CO2 crust, even if there were an atmosphere as dense as Earth's on top of that.
I think he meant This_story_has_been_bouncing_around_for_a_while.h, which contains the prototype for the this_is_old_news() function.
-Daniel
One, this discusses some channels and surface features of craters, not of the whole surface of Mars.
Two, as many people have discussed, CO2 would not be viable as liquid for almost any time at all, in the Martian atmosphere.
However, since they appear in the walls of craters, these channel markings may not have always been surface features. If formed while rock was still overhead, underground pressures may have indeed been high enough to support liquid CO2. A crater is a surface defect caused by a collision.
For all we know, this is the Martian geological equivalent of termite tunnels through ironwood: we don't see the damage until we crack open the outer layers.
I don't have the liberty to check the whole set of data and findings that the scientists have gathered. And neither do 99% of us. Rather than jump to say, on limited information, "gee, that's impossible," I invite people to think about what may be possible. Critical thinking doesn't have to be destructive of theories.
[
Hoffman has a very informative website at http://irian.geolo gy. latrobe.edu.au/~nhoffman/Mars/index.html, much of it comprehensible to non-planetary scientists like me.
PS: can people PLEASE stop saying "canals" when they mean "channels"? It's important: "canals" implies artificiality, "channels" can be natural in origin. (Damn the Italian language for having "canali" as the word for channels.) There are NO canals on Mars, but there are channels.
The real Captain Avatar is a fictional character, so I suppose he doesn't mind if I impersonate him.
I think water is the "right" guess for the cause of the channels. Water is really the only substance we have direct evidence (actually this is not true lava does the same) building channels on earth.
It should be pointed out that when it comes to geological process it is very rare that we have direct observation and/or good experimental evidence to explain the geomorphology of an area.
That being said we can to a pretty good job of explaining things like the grand canyon, even though we haven't been watching it for several million years.
NASA made headlines in June when photographs from the Mars Global Surveyor, a satellite orbiting the planet, showed scores of gullies, channels and deltas on the sides of numerous Martian craters.
I don't think they were attempting to say that all the chanels on Mars were formed by carbon dioxide, just the ones on the sides of the craters. The major gullies on the surface may still have been from water at some point in the far past.
Dirty Pirate Hooker
This is known in the science trade as salami science: slice your work really thin and publish lots of short, incomplete articles so your c.v. looks more impressive. Why can't Wired write a single carefully researched Mars article instead of lots and lots of shallow ones?
The Wired articles are also pretty pathetic because they never include any out-going links to more substantial academic or government articles. If Wired is supposed to be an example of really modern internet journalism, why do they use the web as if it was made of dead trees?
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