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The Physics of Water on Mars

09/11/2012 3:32 PM

In a recent article regarding the latest Mars mission, I was irked by the following comment by a somewhat pretentious self proclaimed expert on Mars. Unfortunately my knowledge isn't deep enough to intelligently respond. Perhaps some of you can fill me in. Here was the statement, to which I refer:

"Explain how you can have water on the surface of Mars with 0.1 BAR of air pressure.

Then explain how a planet as small as Mars could EVER have held enough atmosphere for the pressure to be significantly higher.

This is Physics 101. For some reason NASA people keep IGNORING IT. It just makes them sound like idiots every time they wax poetic about all the water that USED to be on Mars. Almost like the biblical account of the earth being covered in water a mile deep- both violate the laws of physics."

Comments? I don't want to get into the geography and topography issues supporting the theory of considerable water having been present. That's another matter that I am somewhat well versed on. But the air pressure / atmosphere issue is something I'm ignorant of.

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#1

Re: The Physics of Water on Mars

09/11/2012 4:11 PM

This article may shed some light....

http://witcombe.sbc.edu/water/physicsuniverse.html

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#2

Re: The Physics of Water on Mars

09/11/2012 4:12 PM
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#3

Re: The Physics of Water on Mars

09/11/2012 4:54 PM

Water is a very unique molecule. Because of hydrogen bonding water does not have the anticipated phase diagram of a light molecule. A very good in depth analysis of the many phases and triple points of water can be found here.

The phase diagram form there is:

This is not as blurry at the original site. There one can clearly see that a narrow temperature range of 100mbar to about 5mbar will contain liquid water. Now on Mars I would expect freezing to ice Ih will always happen over night. This will reduce losing water to space due to the low vapor pressure of a solid.

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#4
In reply to #3

Re: The Physics of Water on Mars

09/11/2012 6:20 PM

" ... a narrow temperature range of 100mbar to about 5mbar ... " - sorry, you've lost me there.

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#6
In reply to #4

Re: The Physics of Water on Mars

09/11/2012 6:42 PM

(Sorry but I was in a rush before starting a meeting at work.)

There is a narrow temperature range where water is liquid while the pressure is in the range of 100mbar to about 5mbar. OBE asked how liquid [sic] water could exist on the surface of Mars since it has a nominal atmospheric pressure of 100mbar at the surface. The boiling point will be about 50°C for water at 100mbar according to the phase diagram.

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#7
In reply to #6

Re: The Physics of Water on Mars

09/11/2012 7:01 PM

Ah - thanks. Thought it had to mean something like that.

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#5

Re: The Physics of Water on Mars

09/11/2012 6:34 PM

Well I understand the reasoning of a lack of liquid water due to Mars' current state. But the comment states that due to the planet's size, it could never have had sufficient atmosphere to have liquid water. I'm of the opinion that it lost most of its atmosphere due to any one of a number of theories. But to say that it's too small to ever have had enough atmosphere... that's where I'm lost.

And I'm prone to trust the astrophysicists at NASA, more than some blogger online that calls the NASA scientists idiots. I just don't follow his reasoning, to make such a bold statement.

Where's our resident CR4 astrophysicist? Jorrie?

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#8
In reply to #5

Re: The Physics of Water on Mars

09/11/2012 7:08 PM

At one time the consensus opinion about Mars was as you stated, that liquid water could never exist on Mars. There are still some astrophysicists that believe this. Then a cryovolcano was discovered on Neptune's moon Triton by the Voyager probe and many scientists wondered if they were too hasty to discount water on Mars.

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#11
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Re: The Physics of Water on Mars

09/11/2012 10:10 PM

GA by the way.

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#9

Re: The Physics of Water on Mars

09/11/2012 9:20 PM

From my observation of NASA, they have been trying to justify a manned trip to mars for years. The meteor found in the arctic, I doubt that it came from mars. This water theory, another ploy, they did that with the moon too. I'm all for non manned remote robotics, like they're doing now.

What I would really like to see, is 100 Hubble type (greatly simplified) telescopes in orbit. Start with 10 and iterate to a low cost "high volume" design.

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#10
In reply to #9

Re: The Physics of Water on Mars

09/11/2012 9:58 PM

Hmm. Well, simply put, I don't agree with any of your thoughts on this. I could go in to detail on all your points, but I'll just say it this way.

I'm of the belief that humanity on the surface of Mars is our destiny. We've got some true visionaries working on it. Godspeed!

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#12

Re: The Physics of Water on Mars

09/11/2012 10:11 PM

to put it bluntly, why should i or any other tax payer give a sh#t whether mars has or ever had water or living organisms?

what's the benifit? should'nt we be investing the billions spent on something benifical to mankind? deep sea exploration in particular. the information we garner from the sea may be our only hope of survial on THIS PLANET.

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#13
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Re: The Physics of Water on Mars

09/11/2012 10:19 PM

Please, let's not talk about "taxpayers" on CR4. There are other forums that love that stuff.

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#14
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Re: The Physics of Water on Mars

09/11/2012 10:26 PM

citizens?

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#15

Re: The Physics of Water on Mars

09/11/2012 10:57 PM

There's water on Mars because the ice caps are melting from global warming. Obviously, we caused it, just like we did here.

What? Global warming on Mars is caused by solar activity?

http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html

Why are we pouring trillions of dollar down a global warming rathole if the sun is at fault? Obviously, that researcher doesn't understand the politically correct view that we are at fault. No more grant monies for him!

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#16

Re: The Physics of Water on Mars

09/11/2012 11:07 PM

When the rover was on Mars in1999-2000 and sending back pictures, I was very curious and downloaded a LOT of them. And I put my common sense to work. First, imagine it is YOU standing on the surface rather than that car. Why should the sky be a murky orange-brown? We were taught two very contradictory things about Mars in school. One is that there are wicked dust storms on Mars. The second is that the atmosphere of Mars is practically nonexistent. It can't be both; one of them is a lie. I used a simple program came standard with windows 98 that enabled one to increase or decrease the primary pigment content of any picture. I discovered that what NASA had done was to add red to all of the pictures. Remove the red, and a more believable picture emerges. The sky was very earthlike, only slightly more purplish than earth, and I do mean slightly. One day someone at NASA released a picture that had NOT been tampered with. It showed the sky the same color as what I had achieved by removing some of the red. I had initially thought that I hadn't gotten the red proportion quite right. I then realized that Mars's sky really is every so slightly more purplish than Earth's. The pictures of the rover tire tracks told an interesting story. The tire tracks were distinctly darker than the surrounding soil, fairly convincing evidence of moisture in the soil. By removing the red that NASA had added, obvious algae growths (or similar) was noted on many of the rocks. Some of the pictures were in black and white. I noticed that in some of these black and white pictures there were water drops on the camera lens (water distorts light in a peculiar fashion, remember the straw in a glass of water appears bent?). Scientists were pressing NASA to quit screwing with them and release untampered photos. Their major complaint (far from their only complaint) was that the pictures were of ridiculously low resolution. Why go to all the trouble of putting a car on a camera on Mars and send back low low-rez pictures? Somebody in NASA would occasionally release (unauthorized) a high-rez picture which would be removed in a day or two, as well as from the mirror site(s). You want to know the truth? Good luck. When they sent the orbiters to Mars in the 70s, as soon as the pictures came in in color, they turned them all reddish orange. Richard Hoagland was there when it happened and knew of the scam and said nothing about it for 3 decades. He finally did 'fess up. I emailed him and told him I was already aware of the scam and asked him why it took him three decades to cop to it. He, of course, wouldn't answer me.

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#17
In reply to #16

Re: The Physics of Water on Mars

09/11/2012 11:31 PM

You are delusional.

And, after considerable thought, I think you are also psychotic.

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#18
In reply to #17

Re: The Physics of Water on Mars

09/11/2012 11:35 PM

Well now, don't be so harsh. The scientist wouldn't respond to his accusation. I'd say that pretty much proves it

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#19
In reply to #18

Re: The Physics of Water on Mars

09/11/2012 11:41 PM

Forrest Gump's "Stuupid is as ................." applies here.

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#20
In reply to #17

Re: The Physics of Water on Mars

09/12/2012 1:31 AM

If you remove the OT, he will just be psychic.

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#26
In reply to #20

Re: The Physics of Water on Mars

09/12/2012 6:42 AM

HA! Well that was the perfect storm! errmm.. I mean.. tornado.

GA just for clever and lucky.

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#21
In reply to #17

Re: The Physics of Water on Mars

09/12/2012 2:35 AM

Like I told you before, I don't give a rat's furry crack what you think of me. You're stunted intellectually, incapable of thinking for yourself, let alone anything resembling original thought or critical thinking. Until you actually download those same pictures and examine the evidence.... you have no reason to comment. Now, wait a second, here come your friends the moderators to tell me why I should be polite to an a-hole like you who starts in with the insults.

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#27
In reply to #21

Re: The Physics of Water on Mars

09/12/2012 6:56 AM

Jerrys, it's a Conspiracy Theory. If you are intelligent enough to come up with such elaborate hogwash, one would think you would also be intelligent enough to understand why you would be scoffed at by other intelligent beings. No? C'mon, man. Do you truly expect that to be accepted at face value? NASA has absolutely no reason to do what you described. They've nothing to gain, and so very much credibility to lose. An entire generation of Mars scientists is going to stay tight-lipped about a conspiracy like that? Nobody blowing the whistle, before your revelation? Really? See the whole picture, for pete's sake.

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#28
In reply to #27

Re: The Physics of Water on Mars

09/12/2012 10:38 AM

Two people can keep a secret, as long as one of them is dead.

Sometimes when I can not sleep, I go to a conspiracy theory web site. I wake up the next day still laughing.

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#29
In reply to #17

Re: The Physics of Water on Mars

09/13/2012 2:37 AM

yep, delustional.

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#22

Re: The Physics of Water on Mars

09/12/2012 3:24 AM

The history of Mars' atmosphere is both complex and quite incomplete. Mars evidently had considerable surface water at various times and a much higher - and wildly varying - atmospheric pressure at various times in its early history. However, once Mars lost its magnetic field, it lost its protection from the solar wind which has since stripped Mars of much of its atmosphere. Mars still has considerable water, much of it locked up in hydrates and other compounds and in the permanent polar ice caps. These are mostly water ice which, if melted, would cover Mars to average estimated depth of about 3 metres. There is also much evidence for subsurface liquid brine deposits which can be seen in and around the sunlit slopes of craters during the Martian summer.

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#23
In reply to #22

Re: The Physics of Water on Mars

09/12/2012 3:32 AM

Why would a planet lose its magnetic field?

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#24
In reply to #23

Re: The Physics of Water on Mars

09/12/2012 3:39 AM

Cooling. Mars had a molten iron core at one point. Differential rotation produced the magnetic field but, once the core had cooled enough to solidify, the field disappeared, Mars lost its magnetosphere and the rest is history.

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#25

Re: The Physics of Water on Mars

09/12/2012 5:50 AM

The physics of water are independent of whichever planet happens to hold on to it. According to published steam tables, at 0.1bara, water boils at about 45degC.

Water can be found on this planet at 0.1bara. It corresponds to an altitude of about 16200m above sea level, where the temperature is about -57degC. It would solidify if present and form clouds at lower altitudes.

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#30
In reply to #25

Re: The Physics of Water on Mars

09/13/2012 3:40 AM

ice will convert to gas and bypass the liquid stage even here on earth under a very slight pressure drop....i'm referrring to the small pressure drop from vehicals passing over ice patches in low winter temeratures.. anyone livinging in the snow belt sees it every winter during long periods of below freezing temperatures... . does anyone know the composision of theses so called ice caps? ..is it water? i'm very sceptical if it's h2o.... likely ammonia, chorine, or some other gasious chemical that won't evaporatate due to low temperatures and would never provide waterto support life or an atroshere suitable for life.

i'ld like to be proven wrong... it may parcially justify the 100's of billion dollars spent to keep the astro-physicists living there luxury lifestyles.

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#31
In reply to #30

Re: The Physics of Water on Mars

09/14/2012 2:15 PM

Yes ice will sublimate under the right conditions here on Earth. Out on other planets/ moons and space in general, that appears to be a different story. The moon Europa has a ice crust with possible water underneath it. Comets are referred to as dirty ice/ snow balls. These objects have been around for billions of years, yet they still have water/ice/snow, etc. The Martian polar caps are a mixture of water ice and frozen CO2.

The above information is a result of research and space probes. As for their luxury lifestyles. That may be hold true for a senior tenured professor, but most scientist's (graduates, masters, PH D's and post Doc's) that I know spend most of their time looking for funding and live a lot worse than you think.

We need to do research in all fields, other wise we would just be banging rocks together, living in cold dark caves. OK more likely a basic agrarian society.

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#32
In reply to #31

Re: The Physics of Water on Mars

09/14/2012 2:23 PM

Noble effort, but you cannot be rational when a person is irrational. You especially cannot be rational about an unfounded jealousy.

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#33
In reply to #30

Re: The Physics of Water on Mars

09/15/2012 2:34 AM

The Martian polar ice caps contain huge amounts of water ice. It is estimated that the volume of water locked up in the Martian polar ice could cover the entire planet to an average depth of over 3 metres.

During the Martian winter (like Earth, Mars has seasons, and for the same reason: Mars' spin axis is tilted at 25.19 deg. [Earth: 23.44 deg], the surface temperature drops to the point where carbon dioxide condenses directly out of the atmosphere onto the polar (water) ice.

Come spring, when temps start back up, the frozen CO2 undergoes rapid sublimation which results in strong carbon dioxide winds blowing outward from the ice cap. These winds often reach speeds in excess of 400 km/h and can kick up huge dust storms which are seen to engulf the entire planet at times, sometimes for days.

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#34

Re: The Physics of Water on Mars

09/24/2012 2:07 AM

The mean temperature on Mars is -63C. It can sometimes melt, briefly, but it will always freeze soon after. We may even have detected that occurring:
In addition, the pressure is so low that when it does get warm enough to melt, much of it will turn into gas rather than liquid. On earth, there is considerable air pressure helping water remain liquid. In the near-vacuum of the Martian atmosphere, the range of liquid water is even narrower. And once in gas form, some of it leaks off into space before it freezes, further reducing the amount of water available on the surface.

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