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Probable Water Ice Sighted On Mars

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  • Re:Dry ice? (Score:5, Informative)

    by MichaelSmith (789609) on Thursday June 19, 2008 @10:44PM (#23868313) Homepage Journal

    In such a carbon dioxide rich atmosphere, how do we know it is water ice and not frozen CO2? What do we know of the Martian surface and subsurface temperatures?
    Its too warm for solid CO2. Even at night [nasa.gov] the temperature is barely cold [wikipedia.org] enough for carbon dioxide to solidify.
  • by CraftyJack (1031736) on Thursday June 19, 2008 @10:53PM (#23868407)

    the lander doesn't have an "ice" experiment/module on board
    TEGA [arizona.edu] has that capability. Verifying the presence of water ice is an explicit science objective [arizona.edu] of this mission.
  • Re:co2 ice ? (Score:3, Informative)

    by Teilo (91279) on Thursday June 19, 2008 @10:55PM (#23868425) Homepage

    Since CO2 sublimates, and water does not.
    Sorry to have to break it to you, but water ice sublimates [wikipedia.org] also.
  • by pokerdad (1124121) on Thursday June 19, 2008 @10:57PM (#23868457)

    Only if you separate the oxygen from the hydrogen first. That takes energy. Since the atmosphere is mostly carbon dioxide you might as well plan to split it into carbon and oxygen.

    I'm pretty sure the poster (and anyone else who would be browsing slashdot) knew that; the quote is from Dan Quayle, he's the one who needs help.

  • Another article... (Score:5, Informative)

    by yorugua (697900) on Thursday June 19, 2008 @11:02PM (#23868489)

    Another article about the same news: http://blog.wired.com/wiredscience/2008/06/mars-phoenix-tw.html [wired.com]

    There is water ice on Mars within reach of the Mars Phoenix Lander, NASA scientists announced Thursday.

    Photographic evidence settles the debate over the nature of the white material seen in photographs sent back by the craft. As seen in lower left of this image, chunks of the ice sublimed (changed directly from solid to gas) over the course of four days, after the lander's digging exposed them.

    "It must be ice," said the Phoenix Lander's lead investigator, Peter Smith. "These little clumps completely disappearing over the course of a few days, that is perfect evidence that it's ice."

    The confirmation that water ice exists in the area directly surrounding the lander is big and good news for the Martian mission. NASA's stated goal for the Mars Phoenix was to find exactly this -- water ice -- and then analyze it. With the latest news, the first step is accomplished. All that's left now is to get the water into the Phoenix's instruments, a task which has occasionally proven more difficult than anticipated.

    Still, this is the best opportunity that humanity has ever had to analyze extraterrestrial water in any form. That had the Phoenix Lander's persona fired up.

    "Are you ready to celebrate? Well, get ready: We have ICE!!!!! Yes, ICE, *WATER ICE* on Mars! w00t!!! Best day ever!!" the Mars Phoenix Lander tweeted at about 5:15 pm.

    Their suspicions about water ice beneath the surface of Mars confirmed, scientists and the world will have renewed interest in the outcome of the soil analyses currently being conducted by the lander.

    The samples are being examined for traces of organic molecules, among other substances, but the lander does not have instruments that could directly detect life.

    See the full announcement from NASA.

  • Re:co2 ice ? (Score:4, Informative)

    by sjf (3790) on Thursday June 19, 2008 @11:08PM (#23868537)

    You are correct. I had not realized just how low the air pressure was on Mars: it can be around 0.006 atm which is exactly the point where ice will sublimate.
    Cool. Thanks !

    Why the f*ck was I moderated troll ? I was wrong, but trolling ? Sheesh, get a life.

  • by JebusIsLord (566856) on Thursday June 19, 2008 @11:10PM (#23868553) Homepage

    Yes it does and can, at low atmospheric pressures (such as there is on Mars).

  • by GeffDE (712146) on Thursday June 19, 2008 @11:12PM (#23868567)
    H2O ice does sublimate. Here's an easy way to prove it. All you need is a freezer and an ice cube tray.

    1. Fill ice cube tray with water (liquid, H2O water) and put it in freezer.
    2. Go back in a day and mark the level of the ice in the tray.
    3. Return later (preferably at least a week) and marvel at how the ice is below the level marked.
    4. ???
    5. Profit.

    The ice was in the freezer the whole time, so it didn't melt (assuming the freezer was set correctly and continuously powered). Therefore, the solid water lost must have changed to water vapor.
  • by linzeal (197905) on Thursday June 19, 2008 @11:56PM (#23868905) Homepage Journal
    Oil can be used to make fertilizer, plastics and the like. Who said anything about burning it?
  • by hcmtnbiker (925661) on Friday June 20, 2008 @12:13AM (#23869011)
    btw, I feel the need to mention that H2O ice doesn't sublimate, CO2 ice does.

    And I feel the need to mention that Mars is not Standard Temperature and Pressure. The atmospheric pressure on Mars is about 1/100 that of Earth, I honestly don't know if that's reason enough for why H2O may experience sublimation like that, but I'm too tired right now to look it up and/or crunch some numbers and see if it does or not.
  • by Smoke2Joints (915787) on Friday June 20, 2008 @12:25AM (#23869061) Homepage
    the ultimate aim of these mars exploration missions is to check for signs of life BEFORE we start terraforming the shit out of it. science doesnt want unnessicary genocide on its hands, regardless of the sophistication of the species.
  • Ice sublimes. (Score:4, Informative)

    by Dr. Mu (603661) on Friday June 20, 2008 @12:52AM (#23869211)
    Geeks sublimate.

    (Okay, okay, I just looked it up: "sublimate" can also be used with ice, but "sublime" is preferred.)

  • by Deadstick (535032) on Friday June 20, 2008 @01:03AM (#23869261)
    The triple point pressure of water is 0.006 atmospheres, and that is based on the partial pressure of water on the gas side. The total pressure on Mars is about 0.008 atm, so the partial pressure of water in it would be much less than 0.006. Yes, water ice will indeed sublime (which is the preferred form of the verb in a physics context; "sublimate" is used in a sociological context).

    rj

  • by Anonymous Coward on Friday June 20, 2008 @01:24AM (#23869355)

    H2O ice does sublimate. Here's an easy way to prove it. All you need is a freezer and an ice cube tray.

    1. Fill ice cube tray with water (liquid, H2O water) and put it in freezer.

    2. Go back in a day and mark the level of the ice in the tray.

    3. Return later (preferably at least a week) and marvel at how the ice is below the level marked.

    4. ???

    5. Profit.

    The ice was in the freezer the whole time, so it didn't melt (assuming the freezer was set correctly and continuously powered). Therefore, the solid water lost must have changed to water vapor.

    Got a newer freezer? Frost free by any chance? I'm not disagreeing with you about the ice on Mars just the ice in your freezer. In a frost free refridgerator a small amount of ice is lost each day from the defrost cycle. The ice will disappear in a few months where as in an older freezer you'll get more ice from the moisture in the air freezing. Sorry. Also the light goes off when you close the door to keep from wasting power and heating the freezer.
  • by TapeCutter (624760) * on Friday June 20, 2008 @02:00AM (#23869533) Journal
    The reason you get modded to hell is obvious to this 50yo geek and was politely explained by the GP.

    The fact you think space exploration is a waste of time is your opinion, the way you state that opinion is 95% pure troll/flamebait. The unwashed masses of slashdotter do not have a personal grudge against you, you seem incapable of communicating contrary ideas without spewing bile at the same time.

    Also your original post is flat out wrong...

    "All the bad things about climate change, economic collapse, and overpopulation are happening here and now. The ability to use space exploration technology to address these problems won't be realistic for hundreds of years, if ever."

    Space exploration may not fix these problems but how did we find out about them? The effects of AGW and overpopulation have been measured for the last 30-40yrs using space programs such as landsat. As the GP suggested you cannot seperate science into little piles of factoids and then only fund the piles you want to grow, science is both a body of knowledge AND a way of thinking.
  • by flyingfsck (986395) on Friday June 20, 2008 @03:06AM (#23869819)
    There could be, if there are bacteria living in the crust that can hydrolyze methane. Methane, which is not normally considered to be oil, is a hydrocarbon and is the source of our oil and it seems to be everywhere in our solar system. So, yes, there could be oil on the moon too.
  • by pushing-robot (1037830) on Friday June 20, 2008 @03:10AM (#23869837)

    Well, we could just build a bigger catapult on Mars, if only it had some sort of giant fucking mountain, we could build the mass driver along the side of it.

    Like this one [wikipedia.org]?

    You probably want something steeper, though.

    I'll refrain from making a reference to the relative spatial positions of you and the joke. ;)

    But escape velocity isn't really a velocity, as your trajectory is irrelevant. (Assuming it's, you know, above the horizon...) As long as you're traveling above a given speed, you'll escape the gravity well whether you're pointed straight up or towards the horizon.

    The reason we launch rockets vertically is to minimize the time spent in dense atmosphere. You get a lot of drag at low altitudes here on Earth, so it's better to climb quickly and get to where the air is thin as soon as possible.

    Mars is another story: Air pressure at the top of Olympus Mons is only ~0.003 that of Earth sea level. Launching a payload at a shallow angle through that would be no huge waste of energy.

    On the moon (or anywhere that lacks an atmosphere), you could lay the mass driver right down on the surface and it wouldn't make any difference.

  • by Ihlosi (895663) on Friday June 20, 2008 @04:02AM (#23870079)

    H2O ice does sublimate. Here's an easy way to prove it.

    There is absolutely no need to prove that.

    Just pull up a phase diagram of water (google is your friend), look at the lower-left
    corner (i.e. low pressure and low temperature), and what do you see ?

    A line where the solid phase borders on the vapor phase.

    And what's a phase transition from solid phase to vapor phase called ?

    Bingo. Sublimation.

Never try to teach a pig to sing. It wastes your time and annoys the pig. -- Lazarus Long, "Time Enough for Love"

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