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Space Science

NASA Says Mars Rocks Formed in a Salty Sea 362

Posted by michael from the let-there-be-life dept.
NASA has made another announcement, live on NASA TV, regarding the discoveries of the Spirit and Opportunity rovers. They believe that the rocks examined by Opportunity were actually formed in water; that those rocks were actually sediments laid down in a shallow salty sea. They've already had outside scientists examine their data and those scientists concur with the conclusions. NASA has a story with explanations and some photos.
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NASA Says Mars Rocks Formed in a Salty Sea More

NASA Says Mars Rocks Formed in a Salty Sea

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  • This is HUGE NEWS. (Score:3, Interesting)

    by s20451 ( 410424 ) on Tuesday March 23, 2004 @02:18PM (#8647826) Journal
    If this is true, and those rocks truly are sedimentary, they should be full of bacterial fossils. All we have to do is get one of them under a microscope to confirm life on Mars.

  • A Salty Sea on Mars (Score:5, Funny)

    by Captain Tenille ( 250795 ) <jeremy@satanosphere . c om> on Tuesday March 23, 2004 @02:18PM (#8647833) Homepage
    Well, I suppose that would explain the ruins of a Long John Silver's that Viking 2 found in the 70s.

  • Single cell organisms to follow... (Score:4, Interesting)

    by paleobones ( 214654 ) on Tuesday March 23, 2004 @02:19PM (#8647834) Homepage
    I bet they'll soon find some stuff that will look like biological processes. Cool stuff...
    • As was said above, salty sea != life bearing sea. It could have been highly acidic (or highly alkaline), and not been able to support life (as we know it anyway).

      However, it's a major boon to people looking for evidence of biological process on Mars. Sedementary rocks are by far the best ones for preserving that sort of evidence, as well as forming in the most likely place to find life. If we don't find it there, we probably won't find it elsewhere.
      • Big hullabalo a few weeks ago that scientists had shrunk an amino acid detector and analyser to the size of a computer chip. They'll try to get these on the 2009 landers.

  • Ok (Score:5, Insightful)

    by Burgundy Advocate ( 313960 ) on Tuesday March 23, 2004 @02:19PM (#8647837) Homepage
    It's time to get our asses to Mars. There is far too much to learn for us to just sit around and do nothing.

    Especially considering some of this may be applicable to what will happen to our own planet in the future. We currently have seas. Mars used to. It'd be a good idea to figure out why they don't have them anymore.

    • Re:Ok (Score:4, Funny)

      by Dysan2k ( 126022 ) on Tuesday March 23, 2004 @02:24PM (#8647911) Homepage
      Easy... the colonists revolted and the Go'auld decimated the planet.

      • Re:Ok (Score:2)

        by MoFoQ ( 584566 )
        damn that anubis.
        thxfully, he got what was coming....

        but wait, if the planet was decimated, then it shouldn't exist (unless the accended lifeforms remade it for us to talk about on /.)

    • Re:Ok (Score:5, Insightful)

      by steelerguy ( 172075 ) on Tuesday March 23, 2004 @02:33PM (#8648023) Homepage
      Although I agree with you, it would be a dangerous mission. Look at the outrage the explosion of the latest space shuttle caused. Although there would be plenty of astronauts willing to take the risk, my guess is that, no time soon, will they even be given the opportunity.

      It seems that most people have forgotten that this kind of exploration can be dangerous. I think people would be leary of sending Lewis and Clark out in this day...but what if they get sick...what if Clark falls..yadda yadda

      • Re:Ok (Score:5, Interesting)

        by myowntrueself ( 607117 ) on Tuesday March 23, 2004 @04:04PM (#8648985)
        Yeah exploration is *far* too dangerous to risk the lives of American astronauts.

        American astronauts should sit at desks pushing their mouse around playing solitaire or somthing.

        I really pity them... its sad that such cowardice should infect such a (formerly) great nation.

        Yeah *troll*, *flamebait*, *whatever* but its true.

        • Re:Ok (Score:4, Insightful)

          by steelerguy ( 172075 ) on Tuesday March 23, 2004 @06:08PM (#8650352) Homepage
          The sad thing is the astornauts themselves are not the one's complaining. They seem to understand the risks and are willing to take them.

          Making this an anti-American argument was just silly though. In fact, we are much more likely to send people into space than any other country. That is why we have/had so many hitch hikers on the space shuttle missions.

        • Re:Ok (Score:5, Insightful)

          by johnjay ( 230559 ) on Tuesday March 23, 2004 @06:42PM (#8650663)
          On the face of it, it is an inconsistant national philosophy that American soldiers are regularly expected to risk their lives, but space flights are held to a standard of 100% success. America is supposed to be a nation of cowboys. The "cowboy" image is much closer to that of an explorer than a soldier.

          I think it's because space science is held to a perverted form of perfection, rather than because Americans as a people have become cowards. Every time an astronaut dies, the space program is shut down and there is an intense investigation. Inevitably, something is found that could have been done differently/better and prevented the accident. NASA is criticized and expected from then on to make no errors. It is an admirable goal, and has produced some amazing machines and science, but it stifles progress.

          When space travel is so commonplace that it is no longer news, the astronauts will be allowed to take risks. But, until then, the engineers and scientists involved in space will be more concerned with not being the subject of one of those witch-hunts, rather than actually doing something. I am not criticizing the scientists of NASA; I think they are held to unrealistic expectations.

    • Re:Ok (Score:3, Insightful)

      by Hizonner ( 38491 )
      Time to keep our asses off of Mars. There are far too many ways for humans to contaminate the place and make it impossible to learn anything.

    • Re:Ok (Score:2, Informative)

      by homerjs42 ( 568844 ) *
      We currently have seas. Mars used to. It'd be a good idea to figure out why they don't have them anymore.

      Well IANAPA (planetary astronomer), but the general consensus is that any water that was there has mostly evaporated and/or frozen. Mars has a very thin atmosphere, and liquid water would not stay put for long -- just as water boils faster at altitude, this is equivalent to water at a very high altitude. Now how water lasted there for thousands of years (or more likely millions, if it has modified t

      • Re:Ok (Score:3, Funny)

        by Krondor ( 306666 )
        Soudns very reasonable, except, you're forgetting that Martians moved the bulk of their atmoshpere to Earth which they then terraformed into a habitable planet. Of course this was a long long time ago, and the martian overlords have since progressed on leaving us to wonder why we're here.

        Come to think of it this sounds an awful lot like Scientology [xenu.net]. Oh god! They're right! On second thought I think I might listen to too much Clutch [stlyrics.com].

      • Re:Ok (Score:3, Funny)

        by Ryan Amos ( 16972 )
        Hrm, I know you're NAPA (nor am I) but I believe the reason Mars doesn't have an atmosphere isn't the gravity (Mars gravity is pretty close to Earth gravity, something like 0.8g) but rather the lack of a magnetosphere to protect the atmosphere from outside forces (solar flares, etc.) IIRC this is because there is no longer thermal activity in the Martian core, which isn't exactly something we can change in any comprehensible amount of time (say, under a billion years or so.) So it seems the sci-fi geek drea
    • "We did find life on Mars. Samples returned by astronauts to Mars contained bacteria exactly like that found in the human gut and lungs."

      Seriously though, what is Mars going to teach us? What would happen if our planet had about 2/3 it's present mass and was a few million miles farther from the sun? Environmental threats on Earth are almost entirely manmade and the solutions are available right now (population control, etc) but the will is not.

      • Re:What they'd find (Score:5, Insightful)

        by tijnbraun ( 226978 ) on Tuesday March 23, 2004 @03:21PM (#8648525)
        If bacterial fossils would be found, it could possibly tell us a lot about how life orginated on earth.

        The biggest problem with all the hypothesis of the origin of life is that of falsification. This problem is not confined to theories of the genesis of life alone.

        All biologist that want to explain why a certain animal evolved from its ancestors in such a way and not in an other way, have this problem. So do historians. "What would have happened if king George the whatever died at 18 of pneumonia, I assume that germany bla bla ".

        You can probably tell a nice story, but do you have any data to prove your assumptions?. Although biologist often are in a better position to prove their assumptions (there are a lot more animals with the same niches/ancestors, living in different continents/islands evolving in different species in comparison to king George's), it often resorts to just story-telling.

        If life did orginate independently on Mars and any remains of this event could be found and studied, it could not only falsify a lot of hyphotesis but also stir new ones in the right direction

        • Re:What they'd find (Score:3, Insightful)

          by El ( 94934 )
          If evidence of bacterial life was found on Mars, that wouldn't be evidence of independent origin. More likely, it would be cause to suspect a common source, e.g. life originating in asteroids which impacted both Mars and Earth. It is even possible that "life" ejected from one planet in a meteoroid collision survived the trip through space to land on the other planet. Granted, the odds against this are huge, but a lot can happen in 4 billion years.

    • Re:Ok (Score:5, Insightful)

      by Iron Sun ( 227218 ) on Tuesday March 23, 2004 @02:37PM (#8648058)

      Scientists think they have a handle on why. Low atmospheric pressure means that water can't exist in liquid form on the surface any more. Mars' atmosphere was denser billions of years ago during what is called its Noachian period. For various possible reasons (such as a lack of a magnetic field to protect against the stripping solar wind) Mars' atmosphere was mostly lost, and all the water boiled off into vapour, and was either lost to space or deposited in the ice caps.

      A lengthy and detailed overview of current theories can be found here: Part 1 [spacedaily.com], Part 2 [spacedaily.com]. Especially cool is the stuff about Mars' "obliquity cycles", namely the fact that the planet's axial tilt appears to be chaotic, and may have been completely tipped over on its side several times in the past. During such a period Mars would not have ice caps at the poles, but rather an ice belt around its equator.

      • Re: Article pointed to is dated... (Score:5, Interesting)

        by Ralph Spoilsport ( 673134 ) on Tuesday March 23, 2004 @04:37PM (#8649329) Journal
        and it contains this little arrogant gem:

        What we DO know now with reasonable certainty is that such water could not possibly have been any warmer than near-freezing. Noachian Mars may have been "cold and damp", but we can now rule out the view of some hopeful scientists that it must have been "warm and wet".

        Well so much for reasonable certainty, eh?

        AN interesting question those articles do pose, though, is - if Mars was so wet for so long (wet enough to make this sedimentary rock) why is there so much Olivine up there? Olivine breaks down when exposed to water - even frozen water.

        It's a mystery - so I guess we'll just have to pack up the truck and go check it out.

        Swimmin' pools, movie stars...

        RS

  • It was a dead giveaway... (Score:2, Funny)

    by Anonymous Coward
    ...after the discovery of a layer of surfboard wax in the sediments.
  • WOOOOOOO! PAAAAARTY! Show us your tits! Pass the tequila. Where's Shenor Frog'sh at? Adonde esta el bano? Can I get some more salt for my margarita glass?

    You know it's only a matter of time. Really.

  • A Salty Sea? (Score:3, Funny)

    by bcolflesh ( 710514 ) on Tuesday March 23, 2004 @02:21PM (#8647865) Homepage
    Sure, sure - next they'll try to make us swallow Martian seamen!

  • Peer Review? (Score:4, Insightful)

    by TrebleJunkie ( 208060 ) <ezahurak.atlanticbb@net> on Tuesday March 23, 2004 @02:22PM (#8647877) Homepage Journal
    Okay, so they've shown it to a few scientists who concur.

    Whatever happened to *publishing* the results of your experiments (and the data) in peer-reviewed journals?

    Now, granted, there's plenty of political bias in the journals -- anyone that thinks science is purely dealing with the facts these days is *beyond* an idiot, but still. Just because you've got the rovers and you've got a daily press conference doesn't mean that your statements should be treated as anything but sensational speculation this early on.

    If NASA were claiming Cold Fusion or Perpetual Motion, they've be laughed out of the scientific community for broadcasting just a revolutionary claim without first publishing.

    • Well, if they just released it to the media, it may be a bit premature to put together a paper, get it reviewed and published in a journal.

      They better though, or their long-term credibility will surely suffer (At least in the scientific community).

      ~D

    • Re:Peer Review? (Score:4, Insightful)

      by Daniel_Staal ( 609844 ) <DStaal@usa.net> on Tuesday March 23, 2004 @02:29PM (#8647979)
      A print publication has what, a two-three month (minimum) leadtime? I'm sure it'll get published as soon as possible. The article is probably already submitted.

      In the meantime they've had an independent review, and put out the news as quickly as possible. A reasonable compromise.

      • Re:Peer Review? (Score:4, Informative)

        by the gnat ( 153162 ) on Tuesday March 23, 2004 @03:33PM (#8648642)
        A print publication has what, a two-three month (minimum) leadtime?

        Yow. Usually much longer than that - only the absolutely highest profile papers (like Nobel prize material) get into press that quickly. This might, of course, but they don't have any competition so they can take their time getting the details and analysis exactly right.

        Anyway, science by press release usually isn't a good idea, but I'd make some exception for NASA. Even if they get this wrong, the mission has still been a spectacular success, and if they're right, more people will notice now than six months from now when it appears in Science or Nature.

    • Re:Peer Review? (Score:4, Interesting)

      by rabel ( 531545 ) on Tuesday March 23, 2004 @02:31PM (#8647993)
      Dude, this stuff is happening Live, as you see it. The fact that they've had time to let other scientists peer review their work, even at the highest levels, is pretty cool. There will be plenty of peer review going on over the next many years, but for now I think the Mars Rover science teams are going out of their way to make sure they are only reporting what they believe they can prove. None of them has stated that there was life on mars, they're just reporting the facts as they see them.

      I'll bet you they'd be willing to debate the facts with you if you had credentials to match your statements above.

      For now, this is a pretty big deal and one step towards making us wonder seriously if there was life on mars.

    • Re:Peer Review? (Score:5, Interesting)

      by kippy ( 416183 ) on Tuesday March 23, 2004 @02:32PM (#8648015)
      I don't think NASA is claiming anything more than broad speculation with lots of caveats. They're pretty sure there was lots of water. When? How much? How long? Who knows. Since I'm paying for this info anyway, I'm glad they're making it available as quick as they are.

      Besides, isn't releasing this data to the world defacto peer review?

      • Re:Peer Review? (Score:5, Interesting)

        by tfreport ( 458641 ) on Tuesday March 23, 2004 @02:39PM (#8648084)
        Exactly. NASA could have sent it to a journal that would have a handful of scientists look at the arguments (which they are sure to do) or they could let the world know what they were up to and in the process have the entire world analyze things. Sure this data is through a filter of the press, which may make it harder for scientists everywhere to analyze the claim. But they did do it live on NASA TV and surely have information on their website (or soon to). Therefore for you scientists out there, you will have a great opportunity to analyze, scrutinize, etc. a huge finding.

        Meanwhile, Joe Blows like me can actually hear about it and read about it rather quickly, instead of waiting for the filter down process after a peer-reviewed journal down to a general science magazine down to Newsweek or Slashdot. And I am very happy about that. After all, I have at least a couple pennies invested in those two rovers. And I should have a right to know what they have found.

    • Re:Peer Review? (Score:3, Interesting)

      by lobsterGun ( 415085 )

      When NASA shows their results to another group of scientists (peers), doesn't that count for the purposes of peer review? Isn't that what peer review is?

      I thought peer reviewed journals were where you published crap that had already been peer reviewed.

      I'm not a professional research scientist, nor do I play on on TV, or even slashdot. I have done minimal post graduate work. I don't know how these things work. Please educate me if I'm wrong.

      • Re:Peer Review? (Score:3, Informative)

        by Idarubicin ( 579475 )
        I thought peer reviewed journals were where you published crap that had already been peer reviewed.

        Nope. Peer review is a formal process carried out by the journal itself. Each publication has slightly different practices, but the basic process is pretty much consistent. A journal will send copies of your submitted manuscript off to one or more referees--people who are acknowledged to have expertise in the same area. These referees will evaluate whether or not the manuscript is suitable for publicatio

  • Salty sea? (Score:4, Insightful)

    by JordanH ( 75307 ) on Tuesday March 23, 2004 @02:22PM (#8647879) Homepage Journal
    I don't know anything about this area, really, but in seas on the earth isn't it thought that salt accumulation occurs from activities of living (and dying) organisms?

    • Re:Salty sea? (Score:2, Informative)

      by hopemafia ( 155867 )
      Not usually. Salt deposits on earth generally form inorganically...usually because evaporation in a confined body of water causes it to become supersaturated with respect to Na+ and Cl- ions.

    • Re:Salty sea? (Score:5, Informative)

      by Gothmolly ( 148874 ) on Tuesday March 23, 2004 @02:27PM (#8647949)
      No, salt accumulates in the oceans from the erosion of surface soils and rocks, as the minerals wash into larger bodies of water. This may mean that Mars once had rain.
      • One thing I've always wondered, since ice can exist on Mars and there is water vapour in the air, enough to make clouds and frost, can it snow on Mars?

    • Limestone Re:Salty sea? (Score:3, Informative)

      by StefanJ ( 88986 )
      You are probably thinking of limestone. Calcium carbonate.

      If memory serves, limestone isn't necessarily laid down by critters, but finding stromatolites or chalky cliffs ala Dover would be a very good sign indeed.

      As would finding a fossilized opabinia [si.edu], or one of the cannons the Martians used to launch their cylinders [fourmilab.ch] to Earth back in 1898.

      Stefan

  • Next headline you'll see (Score:5, Funny)

    by Tebriel ( 192168 ) on Tuesday March 23, 2004 @02:23PM (#8647892)
    "Opportunity Rover on Strike: Demands Pina Coladas, Sunscreen, and 5 days off to enjoy time at beach."

  • Best thing since first grade! (Score:5, Interesting)

    by Milo Fungus ( 232863 ) on Tuesday March 23, 2004 @02:27PM (#8647953)

    I remember back in Kindergarten when all of my classmates and I wanted to be astronauts when we grew up. All of our dreams were dashed to bits the next year when the Challenger exploded. We all went back to wanting to be fire fighters or whatever.

    I tell you, these Mars rovers have done more to get me excited about space exploration than anything which has happened since then. I'm currently applying to medical school, but a long-dormant part of the back of my mind whispers, "You should have been an astronaut after all!"

    What an amazing day to live in, when we may be at the threshold of discovering LIFE on ANOTHER PLANET!

    • What an amazing day to live in, when we may be at the threshold of discovering LIFE on ANOTHER PLANET! Better yet, we may be at the threshold of creating life on another planet! As far-fetched as the eventual terra-forming of Mars seems, it is much more likely than finding little green men, or even little green bacteria, already living there.
    • Actually, if you were deterred from being an astronaut because of Challenger, then it's probably for the best. No offense, but to be an astronaut you gotta have some huge nuts (so to speak) to ride those flying bombs up to orbit.

      What a great job, but you know... it's probably full of meetings and paperwork and boring-ass busy work most of the time, just like all the rest of us.
    • "I remember back in Kindergarten when all of my classmates and I wanted to be astronauts when we grew up. All of our dreams were dashed to bits the next year when the Challenger exploded. We all went back to wanting to be fire fighters or whatever."

      110 firefighters died in the US in 2003 alone. 17 astronauts have died since 1967.

    • Re:Best thing since first grade! (Score:4, Funny)

      by JavaLord ( 680960 ) on Tuesday March 23, 2004 @02:49PM (#8648184) Journal
      I'd hate to break this to you but...not everyone gets to be an astronaut when they grow up [despair.com]

  • What a discovery!! (Score:4, Funny)

    by DR SoB ( 749180 ) on Tuesday March 23, 2004 @02:30PM (#8647989) Journal
    I can't believe they actually discovered they have rovers over there:

    "NASA has made another announcement, live on NASA TV, regarding the discoveries of the Spirit and Opportunity rovers. "

  • Surf's up on Mars! (Score:5, Funny)

    by HarveyBirdman ( 627248 ) on Tuesday March 23, 2004 @02:38PM (#8648065) Journal
    "It must have been radical," said NASA spokesdude Jeff 'Sex Wax' Corona at a press conference held in a salt water taffy booth in Atlantic City, New Jersey. "The waves would have come in out of the north, and based on our topographic mapping, would have curled perfectly and just tubed out for miles."

    "Would there have been life there?" asked Jayson Blair, new cub reporter for Tool & Die Quarterly.

    "Dude!" said Corona, "With wave action like that how could there not be life? Can't you just imagine the green-skinned Mars babes lounging around, sipping Martain pina colodas while rubbing tanning butter all over their Barsooms."

    "So you think Mars mught have supported intelligent life?" asked Baba O'Reilly, a distant cousin of Bill O'Reilly working for Akron City College Daily Herald, Mid-Morning Edition.

    "Yeah... yeah... those barsooms, man," said Corona. "Huh? What? Oh, well, you wouldn't want them to be too intelligent, you know what I mean, man?"

    The press conference was brough to an early end when a catsuited Gloria Allred and Camille Paglia paraglided into the taffy booth and beat Corona into submission.

  • View the Briefing (Score:2, Informative)

    by stecoop ( 759508 )
    If you're fast enough you can go view the briefing live, if not its archived on this web page: Briefing [nasa.gov]

  • Shai-halud! (Score:4, Funny)

    by Ececheira ( 86172 ) on Tuesday March 23, 2004 @02:57PM (#8648270)
    So, Mars had a Sea and now it's dry and desert-like...

    How long until they find worm-sign?

  • Luck? Or lots of water? (Score:5, Insightful)

    by sampson7 ( 536545 ) on Tuesday March 23, 2004 @03:00PM (#8648318)
    What amazes me isn't so much that they discovered evidence of water on Mars, it's that they've discovered so much of it so quickly!

    This is really the first fully sucessful mission to Mars whose primary function is to search the geologic record for evidence of water -- and not only did they find it -- they found it twice and quickly at that!

    First of all -- kudos to the mission planning team. They picked their landing spots beautifully (and then hit a moving target from a moving target -- this isn't Lawn Darts folks. That alone is impressive.)

    Second -- how much like Earth is Mars??? If the entire planet was covered with Oceans at one point, then (obviously) finding water isn't that remarkable. If, however, Mars is geologically similar to Earth, then 3/4 of the "land" would have been covered with water at one point. But I don't see that.

    Mars seems to have little/no active tectonics -- and therefore no sea floor spreading. Also, since we can't find magenetically charged banding on the ancient Mars "ocean" floor, it suggests to me that Mars simply does have the characteristics that created large oceans like Earth does.

    What I want to know is if the rovers are cabale of taking a thin-section of some of these sedimentary rocks. So much of the ocean floor on our planet is actually microscopic bits of dead diatoms and other creatures -- that would certainly answer the life question!

    Which brings me back to point 1 -- if there isn't that much water, those rocket scientists really did their homework.

    Wow. This is some seriously cool sh*t.

  • any theories (Score:3, Interesting)

    by WormholeFiend ( 674934 ) on Tuesday March 23, 2004 @03:05PM (#8648354)
    on why and how Mars lost its mass, and therefore the gravity necessary to have salty seas, and the probable atmosphere and precipitations to create them?

    suppose Mars was bigger once, and due to a huge impact, lost a good chunk of itself... would it take a long time to reform itself into a spherical planet? Would there be any proof that such an event ever happened?

    • Re:any theories (Score:5, Informative)

      by Keeper ( 56691 ) on Tuesday March 23, 2004 @03:48PM (#8648802)
      The loss of oceans on mars has nothing to do with a loss in mass.

      The magnetic field Mars current has is not capable of protecting it's atmosphere by deflecting solar wind (the solar wind has been eating away at the Martian atmosphere for some time now; I'm not sure if scientists believe mars ever had a magnetic field capable of doing do, but as it's core has cooled off/solidified the magnetic field on the planet today is what it will always have).

      As Mars's atmosphere is stripped away/blown into space, the atmospheric pressure drops. At a certain point, the pressure drops to a point where water cannot exist in liquid form and evaporates -- creating more atmosphere, which then gets stripped away by the solar wind ...

      The cycle continues until all surface water has evaporated or frozen.

  • Why search for fossils? (Score:4, Interesting)

    by Aggrajag ( 716041 ) on Tuesday March 23, 2004 @03:14PM (#8648456)
    What if there's still some form of archbacteria living on Mars? I mean the ones living on earth can survive basically anywhere. Or they could be hibernating as the bacteria on earth are able to do.

  • What IS that?! (Score:3, Interesting)

    by rchoetzlein ( 737745 ) on Tuesday March 23, 2004 @04:35PM (#8649307) Homepage
    What I'd like to know is, what is that clearly visible, dark, yet shiny object in the foreground in the Meridiani Planium image at 97 degs (the largest image download [nasa.gov] has azimuth degree marks)?

    It can't be the Backshell & Parachute which are at 235 degs. It can't be heat shield either, which is much farther away. And from the image, it clearly is much darker and rises above the surface.

    Also interesting is the fact that it lies on one of the bounce marks from the airbags, but none of the other bounce marks have this feature. Its' in line with the distant East Crater (probably by chance), but clearly in the foreground...

  • Not being a smartarse but... (Score:3, Insightful)

    by niittyniemi ( 740307 ) on Tuesday March 23, 2004 @04:59PM (#8649596) Homepage



    Wouldn't a geologist (I'm not but I did) conclude that earlier pictures [nasa.gov] showed clear signs of the rocks being sedimentary?

    Look at the area below Zugspitze in the picture above and then try and tell me with a straightface that those striated rocks are igneous in origin.

    The question is why did they wait so long to announce the fact that there were sedimentary rocks?

    Maybe a geologist could tell me whether there are any igneous rock formations that might look sedimentary & they therefore had to do further analysis.

    • Striations can be laid down by wind-blown dust, or by ashfalls from volcanos, to name just two mechanisms tha tdotn require wqter at all. Adn we know that there were volcanoes. If there was an atmosphere at some point, there would have been wind-blown dust. Even in the "wet" category, layers can be created by streams or freshwater lakes. So the 'wet salty' part is also not at all implied by the observation of striated rock alone.

  • Liquid != H2O (Score:4, Interesting)

    by F00F ( 252082 ) on Tuesday March 23, 2004 @05:23PM (#8649849)

    I've read a lot of discussions lately about recent evidence for why there must, at one time, have been liquid water on Mars. But, much of that evidence relates to the deposition of sediment, presence of erosion patterns, aftereffects of evaporation, presence of salts, crystallization patterns, and so forth -- none of which (to my knowledge) requiring the liquid in question to be H2O. Some of the evidence, on the other hand, relates to the formation of minerals such as hematite, which presumably form only in or near liquid H2O, and not, say, liquid H2O2, liquid CO2, or liquid N2. The biggest question(s) I have that I've not seen well addressed are:

    1. What evidence supports or rules out the presence of liquids other than H2O on the surface of Mars, at one time, in large quantities?

    2. How much, if any, of the present evidence could be explained by flows of liquid CO2, nitrogen, methane, ammonia, or some other liquid?

    3. Which evidence, if any, points most strongly to the presence of large amounts of H2O as the liquid in question? I know there are currently thought to be large, polar caps of solid H2O, but how much of the current evidence precludes the existence of large seas of some other liquid in the distant geological past?

    I apologize if these questions are simple or completely baseless. I am not a geologist, and am legitimately curious.

    Cheers,

    F00F

    • Re:Liquid != H2O (Score:5, Informative)

      by kindbud ( 90044 ) on Tuesday March 23, 2004 @08:52PM (#8651744) Homepage
      1. What evidence supports or rules out the presence of liquids other than H2O on the surface of Mars, at one time, in large quantities?

      No evidence supports any such thing. Nothing rules it out, however, see answer to question #2.

      2. How much, if any, of the present evidence could be explained by flows of liquid CO2, nitrogen, methane, ammonia, or some other liquid?

      None. The chloride and bromide salts found are soluble in water, not any of those other liquids. By definition, chemical compunds classified as salts require the presence of water.

      3. Which evidence, if any, points most strongly to the presence of large amounts of H2O as the liquid in question?

      The presence of chloride and bromide salt deposits. They can't be formed any other way, but by precipitation from solution in water. The presence of hematite by itself is less conclusive than that, but in the presence of the salts, it adds to the certainty that water was present.

      I know there are currently thought to be large, polar caps of solid H2O, but how much of the current evidence precludes the existence of large seas of some other liquid in the distant geological past?

      The salt evidence excludes the other liquids.

    • Re:Liquid != H2O (Score:4, Informative)

      by DrMorpheus ( 642706 ) on Tuesday March 23, 2004 @11:17PM (#8652852) Homepage
      1. What evidence supports or rules out the presence of liquids other than H2O on the surface of Mars, at one time, in large quantities?

      Short answer, temperature. It's way, way, way too warm for any liquid like N2 or methane or ammonia to form as a liquid. And it's always been too warm. So the probability that the rock formations occured from any of those liquids is precisely zero.

      Secondly, H2O2 is highly unstable, it quickly decomposes into plain-old H2O and O2 in sunlight and/or temperatures above freezing. Both conditions exist and have existed on Mars for billions of years so there is zero probability that H2O2 had anything to do with it.

      2. How much, if any, of the present evidence could be explained by flows of liquid CO2, nitrogen, methane, ammonia, or some other liquid?

      Zero evidences for all of those substances. Again, its far, far, far too warm. First, carbon dioxide does not exist in liquid form at atmospheric pressure at any temperature. It requires a temperature of 20 degress Celsius and a pressure of 30 atmospheres to form. Mars has never had such conditions so there is again, zero chance liquid CO2 had anything to do with Mars' sedimentary rocks.

      The other compounds on your list require extremely cold temperatures to form into liquids. Far, far colder than it EVER gets on Mars for most of them. It also requires a much higher atmospheric pressure than Mars had for most it's existence. Finally, there isn't sufficient quantities of some of these compounds to form rivers, lakes or oceans, nor is there any evidence of that there ever was enough.
      Here's the list of temperatures:

      • Nitrogen == -196 degrees Celsius @ 1 atmosphere of pressure
      • Methane == -162 degrees Celsius @ 1 atmosphere of pressure
      • Ammonia == -33 degrees Celsius @ 1 atmosphere of pressure
        It gets cold enough on Mars for this, but there is very, very little amounts of it.

      Which evidence, if any, points most strongly to the presence of large amounts of H2O as the liquid in question? I know there are currently thought to be large, polar caps of solid H2O, but how much of the current evidence precludes the existence of large seas of some other liquid in the distant geological past?
      You answered your own question, the Martian polars caps consist almost entirely of ice [spacedaily.com]. Enough ice that if they were melted they could form seas covering the entire surface of Mars 15 meters deep [nasa.gov].

  • My Mozilla Tabs say... (Score:5, Funny)

    by rat7307 ( 218353 ) on Tuesday March 23, 2004 @09:14PM (#8651872)
    OT: but I had to share it:
    My current titles on my tabs in Mozilla say:

    "NASA Finds Critical Ass...."

    and

    "NASA Says Mars Rocks..."

    Kinda funny...

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