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Mars NASA Space Science

Confirmed: Water Once Flowed On Mars 113

Posted by Soulskill from the john-carter-spilled-his-beverage dept.
An anonymous reader writes "A new study based on observations last September by the Curiosity rover on Mars has confirmed that pebble-containing slabs of rock found on the Martian surface were part of an ancient streambed. The work provides some of the most definitive evidence yet that water once flowed on Mars. '[The pebbles'] smooth appearance is identical to gravels found in rivers on Earth. Rock fragments that bounce along the bottom of a stream of water will have their edges knocked off, and when these pebbles finally come to rest they will often align in a characteristic overlapping fashion. ...It is confirmation that water has played its part in sculpting not only this huge equatorial bowl but by implication many of the other landforms seen on the planet.' According to NASA, 'The stream carried the gravels at least a few miles, or kilometers, the researchers estimated. The atmosphere of modern Mars is too thin to make a sustained stream flow of water possible, though the planet holds large quantities of water ice. Several types of evidence have indicated that ancient Mars had diverse environments with liquid water. However, none but these rocks found by Curiosity could provide the type of stream flow information published this week. Curiosity's images of conglomerate rocks indicate that atmospheric conditions at Gale Crater once enabled the flow of liquid water on the Martian surface.'"
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Confirmed: Water Once Flowed On Mars More

Confirmed: Water Once Flowed On Mars

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  • I realize I could easily look it up. But, what is the leading theory as to why the planet can no longer sustain liquid water. I know that in it's current condition with low gravity and lack of atmosphere it cannot sustain liquid water... But was Mars once larger?

    • Re:What happened to it? (Score:4, Informative)

      by averdung ( 2848073 ) on Friday May 31, 2013 @11:28AM (#43874053)

      I realize I could easily look it up. But, what is the leading theory as to why the planet can no longer sustain liquid water. I know that in it's current condition with low gravity and lack of atmosphere it cannot sustain liquid water... But was Mars once larger?

      Runaway atmosphere loss is a leading candidate due to a lack of a magnetic field (and those missing gigatons of rock)...

      • Atmospheric Ionization from solar wind.

        • Question about the atmosphere knocked off of Mars- some of it would probably not achieve escape velocity, and eventually fall back to Mars. But some would be moving fast enough to escape. Are there any theories as to where this mass went? Might sizable portions have wound up on Earth or Jupiter? The asteroid belt? Or is most of it still orbiting independently? Unless it achieves solar escape velocity (34.1 km/s at Mars) it seems like it would eventually fall towards the sun unless it hits a planet/moo

      • The lack of a magnetic field might indeed be the explanation, but right now the case for it is not very strong. At least with the current solar activity, the observed atmospheric mass loss rates from Earth, Venus and Mars are comparable, even though only Earth has a significant magnetic field. There is a good article about these issues here [space.com]

    • Comment removed (Score:5, Funny)

      by account_deleted ( 4530225 ) on Friday May 31, 2013 @11:28AM (#43874059)
      Comment removed based on user account deletion

      • Re: (Score:1)

        by Anonymous Coward

        here [imdb.com] is your answer.

        mod parent up :)

    • I recall this being due to an ancient impact that blasted away most the atmosphere, etc. I was watching some show (perhaps The Universe) that explained that there in fact lies a huge impact crater on most of the face of Mars that coincides with this theory. Just a quick Google gave me this [space.com] link -- though I got my information from the aforementioned tv show and not the link.

      • Re: (Score:2, Informative)

        by Anonymous Coward

        I disagree. The prevailing theory is that solar wind tore at the atmosphere gradually due to the lack of a magnetosphere.

        This itself accounts for all of the loss. In fact, it is a bit hard to explain how Mars did actually maintain an atmosphere for as long as it appears to have. Perhaps it has a weak magnetosphere in the past...

        There is an impact crater that's pretty massive, but Earth has several of those too...

        • One of those "impact craters" is our core creating that megasexy magnetosphere.

        • Seems to me that those two factors combined could be the cause... impact plus solar winds. Result: no magnetosphere, not enough mass to sustain atmosphere, and solar winds slowly doing the rest.

          With more mass and different geologic pre-impact conditions, it likely had enough of everything to maintain an atmosphere.

          The bigger question is why our ancestors abandoned the planet and then nuked it and stole the atmosphere, but left the water.... :D

      • Comment removed based on user account deletion

    • Re:What happened to it? (Score:4, Funny)

      by basicasic ( 1185047 ) on Friday May 31, 2013 @11:57AM (#43874429)
      The original liquid was of course heavy water which (as every schoolboy knows) breaks down over time to become ordinary light water. This then floated off into space.
    • If there is no magnetic field protecting the atmosphere, radiation can break down the water molecules into hydrogen and oxygen. The hydrogen will then escape. As you might know water molecules have strong greenhouse effect, or they keep Mars warm. After loosing some of the water in atmosphere, Mars could not keep the temperature above freezing point, then the water left would be frozen.

  • Water in particular? (Score:5, Insightful)

    by Anonymous Coward on Friday May 31, 2013 @11:33AM (#43874103)

    Perhaps I'm missing something, but the evidence cited in the article only seems to show that liquid of some kind once flowed on Mars. What further evidence do we have to think that it was water in particular?

    • Re: (Score:3, Funny)

      by quonsar ( 61695 )
      More likely to have been vodka according to my research.

    • Re: (Score:1)

      by RS449 ( 2859563 )
      It was Slurm...

    • Re:Water in particular? (Score:5, Informative)

      by Antipater ( 2053064 ) on Friday May 31, 2013 @11:48AM (#43874305)
      Extremely hot or cold liquids would have done more to the pebbles than just knock their edges off - we can figure pretty well that they weren't melted or supercooled. The simplest conclusion for "liquid that flows in streams at the temperature range in question" would be either "water" or "the blood of thine enemies".

    • Re: (Score:2)

      by Anonymous Coward

      the reason for mars lack of atmosphere (or at least too thin atmosphere) is due to the end of tectonism and vulcanism in the planet.

      earth loses gases all the time, but those get replenished by the gas that leaks from vulcans and tectonic plate borders.

      theres a balance between gas lost to space and gas gained from lava

      mars is a small planet, so its tectonism and vulcanism faded a long time ago, so it started to lose more gas than it got from lava, and the pressure dropped.

      Lower atmospheric pressure means tha

    • I'd venture a guess that given the atmosphere, temperatures, and composition of Mars, liquid water flowing is the most logical culprit. Not cold enough for liquid nitrogen or helium, not enough mercury to cause it. Maybe ammonia is unlikely for some reason? And if it were beer, fine wine, whiskey, or gasoline, we'd already be halfway to Mars by now.

    • Re:Water in particular? (Score:4, Insightful)

      by steelfood ( 895457 ) on Friday May 31, 2013 @01:15PM (#43875719)

      What other liquid did you have in mind? Water is about the simplest, most abundant, and most versatile liquid out there. Most other naturally-occurring liquids are not liquids in the Martian temperature range, or too complex for there to be a significant amount of (and this applies to the entire universe in general as well, though there may be localized anomolies).

      Unless you're positing that it was something organic like oil, or artificial like formaldehyde, there's no other likely candidate liquid that's abundant, operates at those temperatures, and with that viscosity. Don't forget that CO2, the only other abundant substance on Mars, subliminates under 5 atm, and we know the Martian atmospheric pressure is lighter than ours.

    • Re: (Score:2)

      by yusing ( 216625 )

      We don't have further evidence at present. There are multiple ways in which pebbles might be rounded.

      Much of what people think has been done by water on Mars surface could be done over eons by sand and fines suspended in winds. The winds may have been much stronger in the past. Over eons, the spacial orientation of rocks can change, again for many reasons, which gives prevailing winds access to multiple faces.

      In the long term, rounded pebbles along with several other phenomena *all in the same location* may

  • Geology (Score:5, Informative)

    by Anonymous Coward on Friday May 31, 2013 @11:35AM (#43874137)

    The thick crustal material and low magnetic field have led to the loss of the atmosphere and lack of currently flowing water. Low magnetic field led to large impingement by solar wind and stripping of atmosphere. Low average density of planet let atmosphere escape. The thick crust has kept the mantle deep and there is no regeneration of gases and liquids from the interior. Low atmosphere, more radiational cooling and first water goes to ice and then CO2 goes to ice and reduces the atmosphere again. The Earth could have gone the same route, had an impact not spawned the moon and thined the planet of the lighter, thicker crustal material. Lots of imparted spin from the impact and a denser planet gets deep iron core spin to generate a protective magentic field. That field both protects the atmosphere and the biologicals from getting zapped. Would be fun to send lots of water and gas bearing comets to impact and terraform Mars, but it would all still leak out. So --- we are seeing prehistoric water, frozen in time,and relected by the rounded pebbles left behind in ancient Martian canals.

    • Re: (Score:2)

      by gl4ss ( 559668 )

      The thick crustal material and low magnetic field have led to the loss of the atmosphere and lack of currently flowing water. Low magnetic field led to large impingement by solar wind and stripping of atmosphere. Low average density of planet let atmosphere escape. The thick crust has kept the mantle deep and there is no regeneration of gases and liquids from the interior. Low atmosphere, more radiational cooling and first water goes to ice and then CO2 goes to ice and reduces the atmosphere again. The Earth could have gone the same route, had an impact not spawned the moon and thined the planet of the lighter, thicker crustal material. Lots of imparted spin from the impact and a denser planet gets deep iron core spin to generate a protective magentic field. That field both protects the atmosphere and the biologicals from getting zapped. Would be fun to send lots of water and gas bearing comets to impact and terraform Mars, but it would all still leak out. So --- we are seeing prehistoric water, frozen in time,and relected by the rounded pebbles left behind in ancient Martian canals.

      well it's obvious what we need to do. build a red slave shield around mars. then the ur-quans will all be "like wtf we were here already??" and just go on their merry way while we hold two nice planets.

    • Would be fun to send lots of water and gas bearing comets to impact and terraform Mars, but it would all still leak out.

      You need to think bigger... Re-read that part about thinning the Earth's crust and spinning up a mag-shield. Now, that's terraforming.

    • No, there are no canals on Mars, you anti-scientific moron. Canals are artificial, they are made by MARTIANS!@#@!# Go back to your religion and constitution-worshipping wingnuts. Canals! On Mars! Modded +5 Informative! Ugh makes me want to puke when I see this sort of garbage in public.

    • The thick crustal material and low magnetic field have led to the loss of the atmosphere and lack of currently flowing water. Low magnetic field led to large impingement by solar wind and stripping of atmosphere. Low average density of planet let atmosphere escape. The thick crust has kept the mantle deep and there is no regeneration of gases and liquids from the interior. Low atmosphere, more radiational cooling and first water goes to ice and then CO2 goes to ice and reduces the atmosphere again. The Earth could have gone the same route, had an impact not spawned the moon and thined the planet of the lighter, thicker crustal material. Lots of imparted spin from the impact and a denser planet gets deep iron core spin to generate a protective magentic field. That field both protects the atmosphere and the biologicals from getting zapped. Would be fun to send lots of water and gas bearing comets to impact and terraform Mars, but it would all still leak out. So --- we are seeing prehistoric water, frozen in time,and relected by the rounded pebbles left behind in ancient Martian canals.

      Wouldn't the question be, given those conditions, not be where did the water go, but how did it ever form in the first place?

  • It could have been any liquid with similar viscosity.

    • Re: (Score:1)

      by Tablizer ( 95088 )

      It could have been any liquid with similar viscosity.

      Martian blood?

    • Re:How does this confirm it was water? (Score:5, Informative)

      by Anonymous Coward on Friday May 31, 2013 @11:52AM (#43874367)

      There are few other candidate liquids. We know Mars has water ice. We've detected liquid methane elsewhere in the solar system, but Mars is too warm to support liquid methane. Liquid CO2 is unlikely because at Mars' current temperatures, you would need more than one Earth atmosphere of pressure to form a liquid, and a thicker atmosphere will usually mean a warmer planet.

      • Liquid CO2 is unlikely because at Mars' current temperatures, you would need more than one Earth atmosphere of pressure

        And at ANY temperature....

        Just sayin...

    • .... such as....

      Similar viscosity, which remains liquid at the approximate temperature of Mars now and in recent past, that can dissolve a number of the minerals seen in sediment... AND can exist in large quantities.

      Water... and.... uhm.... dihydrogen monoxide...

    • Except, we already found water, and chemical reactions that indicate the presence of water. Now we also have evidence the water gathered and flowed.

  • The image caption reads: "The team only has pictures from the rover's main cameras. Attempts will be made to get close-up, high-resolution imagery of Gale's conglomerates in the weeks ahead using the Mahli "hand lens"."

    The rover is long gone from that area. I hope they got some close-ups. Unless they want to make a "U" and do some major back-tracking, I hope this is just a case of mixing an old article with new content, being the top says, "updated".

  • Does this tell us water flowed, or merely a liquid?

    It says a stream bed, but could this have been liquid CO2 or something else at some point?

    I'm sure the chemistry tells them a lot, and I trust the NASA guys to know much more than I do, just curious if this specifically confirms 'water'.

    • Re: (Score:2)

      by gewalker ( 57809 )

      You don't get liquid CO2 without quite a bit of pressure, a minimum of 75 psi / 517 kPa (5.1 atmospheres) at the triple point for CO2. Not near enough CO2 for those kind of pressures on Mars.

      • Re: (Score:2)

        by Kozz ( 7764 )

        You don't get liquid CO2 without quite a bit of pressure, a minimum of 75 psi / 517 kPa (5.1 atmospheres) at the triple point for CO2. Not near enough CO2 for those kind of pressures on Mars.

        I admit I'm not much for chemistry or physics. I find them interesting, but they're not my strong suit. What about methane, ethane, etc? For example, the lakes of methane on Titan? I wonder if they could produce similar results? Would conditions on Mars in the past have prohibited this as well?

        • methane at earth atmosphere's pressure freezes at -296 degrees F (-182 degrees C). With a lower pressure atmosphere that temperature would be even lower! Mars is too hot for liquid methane. Note that there IS trace amounts of methane gas on Mars, and that is a mystery.

    • Re:Need it have been water? (Score:4, Interesting)

      by eggstasy ( 458692 ) on Friday May 31, 2013 @12:12PM (#43874669) Journal

      There is no such thing as liquid CO2. Only artificially high pressures can prevent it from sublimating, and as I'm sure you realize, a planet that can't even retain its atmosphere is unlikely to have somehow maintained an atmospheric pressure 5 times that of the Earth in the past.
      Water is an extremely common and simple substance that you can find all over the universe.
      So according to Occam's razor... what else could it possibly have been?

      • Re: (Score:2)

        by chihowa ( 366380 )

        It's not possible to have liquid CO2 on the surface of Mars, but please don't say things like this:

        There is no such thing as liquid CO2. Only artificially high pressures can prevent it from sublimating,

        There is such a thing as liquid CO2 [wikipedia.org] and there's nothing artificial about high pressures. People seem to be getting less and less capable of basic scientific reasoning all of the time. Please don't accelerate that by muddying the waters.

        • Terribly sorry, let me rephrase that more carefully. There is no such thing as liquid CO2 on the surface of the Earth, or on Mars, or under any conditions the average layman may experience over the course of a normal life, i.e. at the standard pressure of 1 atm, let alone at the standard pressure on Mars, where it's 1% of that.
          The average layman may sometimes hear about liquid CO2 somewhere, but it's probably something produced artificially at higher pressures.
          Dry ice, in summary, does not melt, it evapora

          • Re: (Score:2)

            by chihowa ( 366380 )

            I understand not bothering people with unnecessary details, but you made an absolute statement that is not universally valid, even in the context discussed (astronomy). I have considerable research and teaching experience (though I'm not going to participate in the boorish qualification naming), and a very real problem is that people remember the things you say with authority. If you make an absolute statement, people will remember it and apply it out of context. It's easy enough to qualify most statements

    • There are really no other candidates that occur in any volume in the solar system.

      Sure, there are a few elements that are also liquid at comparable temperature and pressure. Kerosene and ethanol, for example. But something that would spontaneously form a long-lasting river on a planetary surface... mostly just water.

      Besides, the few times the rovers have attempted to dig into the soil on Mars, they found water ice just under the surface. Pretty good indicator that the area once had substantial amounts of

  • What is wrong with "Water confirmed to have once flowed on Mars"? Knowing Slashdot it would probably have read "flown" though.

    • Knowing Slashdot it would probably have read "flown" though.

      Nope, flowed is a past tense of flow, flown is a past tense of fly.

      Which is why I long ago gave up correcting non-native speakers of English, and have discovered that sometimes garbled English is actually far more expressive and accurate than 'proper' English.

      Some of the best puns I've heard are grammatically incorrect, but completely on-point in context.

      • Re: (Score:2, Informative)

        by Anonymous Coward

        Knowing Slashdot it would probably have read "flown" though.

        Nope, flowed is a past tense of flow, flown is a past tense of fly.

        Which is why I long ago gave up correcting non-native speakers of English, and have discovered that sometimes garbled English is actually far more expressive and accurate than 'proper' English.

        Some of the best puns I've heard are grammatically incorrect, but completely on-point in context.

        Flew is the past tense of fly, flown is the past participle.

        • Flew is the past tense of fly, flown is the past participle.

          Dude, you can't be that good of a grammar nazi and do it anonymously. ;-)

    • Not sure about that. If it was read as "flown" I'd think we be reading more analogies tiring to relate something to swallow airspeed velocities.

  • Sun cycles (Score:3, Interesting)

    by Anonymous Coward on Friday May 31, 2013 @11:45AM (#43874265)

    And it will again. I'm convinced that the sun has hot and cold cycles. As it warms up, the water on Earth will be vaporized and the ice on Mars will melt. Then it cools and reverses that. Nature's test then is can we develop far enough quickly enough to get to the other planet before it's too late. Of course, this is just idle conjecture. :)

    • It had to be much hotter their for water to flow. Fresh water freeze's at 32 degrees. How much hotter would it have to be on earth in order for the sun to warm mars to at least 33 degrees.Saltwater fully saturated with salt -21 degrees unless of-course Mars could have been a lot closer to earth at one time. I dont see how it would workout otherwise.

      • Re: (Score:2)

        by stjobe ( 78285 )

        Fresh water freeze's at 32 degrees.

        It does not, you bumbling hack. Fresh water freezes at zero degrees.

        Seriously, leave Burma and Liberia behind and get with the program.

  • Martian Republican party once ruled on Mars ;)

  • I gathered there was flowing water there from this photo. http://www.astronomynotes.com/solarsys/pics/eberswalde_deltasm.jpg [astronomynotes.com]

  • > Confirmed: Water Once Flowed On Mars

    I knew it! I knew those longboats with sails sailing across the dry sand were the product of someone's fevered imagination!

  • I'm glad to see strong evidence of water on Mars, after so much conjecture and build-up. It will make it that much more humbling when they DON'T find any evidence of life on Mars.

  • AP - Today at NASA there was a celebration. For the 100th time it has been able to confirm that there was water on Mars. Vint Norgecrack, Director of Mars Water Confirmations, said, "This time we really know it. Again. Honestly, truly, really, for real, pinky swear and all that."

    NASA use this news to appeal to Congress to fund the Mars Planetary Water Finder. The MPF is a $22 billion project meant to send smaller probes to all currently existing landing sites and confirm that the confirmations of confirmat

  • "The stream carried the gravels at least a few miles, or kilometers, the researchers estimated..."

    You'd think by now they would have chosen a damn system of measurement and stuck with it!!!







    (link for those who just heard a woosh [wikipedia.org])

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