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Mars Space Science

A Third of Mars Could Have Been Underwater 167

Posted by timothy
from the younger-hotter-ocean-that-is dept.
Matt_dk writes "An international team of scientists who analyzed data from the Gamma Ray Spectrometer onboard NASA's Mars Odyssey reports new evidence for the controversial idea that oceans once covered about a third of ancient Mars. 'We compared Gamma Ray Spectrometer data on potassium, thorium and iron above and below a shoreline believed to mark an ancient ocean that covered a third of Mars' surface, and an inner shoreline believed to mark a younger, smaller ocean.'"
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A Third of Mars Could Have Been Underwater

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  • Dross (Score:2, Interesting)

    by zoomshorts (137587) on Tuesday November 18, 2008 @11:04AM (#25801563)

    We are living on dross, http://en.wikipedia.org/wiki/Dross the impurities on the surface of a molten ball of nickel/iron
    that takes billions of years to cool, geologically speaking.

    Global cooling is the long range prognosis for us, just as Mars. Mars gets less solar power, being more distant from the sun.
    Mars HAD an earth-similar composition 2 billion years ago. It is what the Earth will look like in the future. Deal with it.

  • Why water? (Score:0, Interesting)

    by Anonymous Coward on Tuesday November 18, 2008 @11:07AM (#25801593)

    I find it strange how many scientists insist on a water body to have carved the different features of Mars. The new theory of a really big impact as a source of the lowlands makes far more sense, explains the big "cracks" in the Mars surface far better, especially their alignment, and so on.

    The "river beds" and "river deltas" can easily be explained with lava flow, especially after the planet heated up a lot due to the impact. The sediment layers may or may not be the remnants of vulcanism, asteroid impacts, storms, and so on.

    As the planet seems to be pretty sandy, I suppose most water, if it was ever pushed to the surface by vulcanism or the likes, would probably faster sink down again then the lava needs to cool down.

    Not to mention that I didn't find the connection with Thorium, Potassium, and Iron - do our volcanic-ridge-free oceans have similarily high concentrations of those? Or is it only the oceans with high volcanic activity? Are there other possible sources for those elements?

    There are so many interesting planets - I find it unusual that so much money is used for this one, which is probably among the least likely to ever have had life. A rover (or similar) on all the planets and moons which are not too hostile for our level of technology would be much cooler, I think. Not to mention manned missions - I suppose establishing a permanent and fairly self-sufficient outpost on the moon or even Mars would be a million times more valuable to humanity then all the probes together...

  • Why controversial? (Score:5, Interesting)

    by Tacubaruba (553520) on Tuesday November 18, 2008 @11:29AM (#25801865)
    Haven't we gotten past the point where the idea of Mars once having lots of water is controversial? I mean, it seems as if every new piece of evidence points in that direction, so what exactly still makes it controversial?
  • by SBacks (1286786) on Tuesday November 18, 2008 @11:31AM (#25801885)

    You mean interesting as in "Hmmm, we might want to have some means of space exploration in the next century at the latest"

    A century is a very short amount of time on the solar timeline. The Earth won't fall into the Sun for 5 billion years or so, and even then, the Sun will have lost enough mass that models predict the Earth may be flung off into deep space rather than falling into the Sun.

    The more immediate concern is that over the next 1 billion years, the luminosity of the Sun will increase about 10% or so, which should be fairly devastating to life on Earth. But, thats due to the Sun getting older, not the Earth getting closer.

  • by cnettel (836611) on Tuesday November 18, 2008 @12:06PM (#25802317)

    At some point we have massive evaporation, which would tend to go catastrophic, i.e. Venus (water vapor is extremely potent as a greenhouse gas). A temperature above which proteins in most organisms coagulate would bring us down to archea. Photosynthesis in its current form also prefers lower temperatures. We know very little of what situations complex multicellular life can really adapt to, but we can say that Earth would no longer be within the range that we consider to be habitable when we do armchair analyses of exoplanets.

    It's not life as we know it, Jim.

  • Two sides to this. (Score:3, Interesting)

    by jd (1658) <[moc.oohay] [ta] [kapimi]> on Tuesday November 18, 2008 @12:14PM (#25802485) Homepage Journal

    First, as others have noted, there is a massive level of sheer scientific curiosity. Prior to this, we didn't know of any planet other than Earth that ever had liquid water on it. We had no idea if such planets were rare or common, or even how to identify them if the water wasn't extremely visible and obvious. This allows us to know so much more about planets and their evolution in early solar systems than we ever knew before.

    Then, there is another side. Water, particularly if it is mildly acidic, leaves open the possibility of cave systems. Cave systems make manned exploration a more realistic possibility, as you're better shielded from cosmic radiation, much better shielded from dust devils, and have a (comparatively) easy environment to seal and pressurize.

    Finally, the combination of a lower gravity and a lower air pressure (whilst a significant atmosphere lasted) may make for crystals that are very different from those that form naturally on Earth. They should be slightly higher purity, for a start. This would not pay for exploration of Mars, or even significantly offset the costs, but it might well intrigue enough of the uber-rich (who tend to like unique trinkets) to either coerce Governments to fund exploration or provide some of the money themselves, purely for the bragging rights of having superior-grade, all-natural, extraterrestrial gemstones.

  • Re:To prove it... (Score:3, Interesting)

    by harry666t (1062422) <harry666t.gmail@com> on Tuesday November 18, 2008 @12:24PM (#25802679)
    Interesting hypothesis.

    I have recently read a book that was supposedly written by an alien. He claimed that: the Moon is empty inside and is a home to a race of living beings that are on a very high level of spiritual evolution, the global warming is caused solely by the sun (and the other planets of the solar system are warming up too), that there was a very advanced (more advanced than ours, both technologically and spiritually) civilization on Earth millenia ago, that vanished due to a world war in which nuclear weapons were used, that the fact that Mesopotamian or Aztec civilizations seemed to appear "out of nowhere" is due to the survivors of the ancient WW, the lack of visible "side effects" (radiation) of the WW is due to a terraforming technology that involved "changing the atomic state of chemical elements by shooting out protons and electrons using condensed streams of photons" (or however someone more fluent in English would translate this from Polish), which is the technology we are going to use to recover Earth after World War III (which is going to start in a few decades), that humans are the only race in our galaxy that does not preserve their memories during reincarnation (this ought to be a side effect of an artificial "law of Karma", and could be undone if we wish to), that there is a great disproportion between the state of our technological and spiritual advancement (again, the greatest in the galaxy), that we are in a constant danger from a few alien races that would want us dead (they're supposed to have weapons that could destroy souls -- a final death, reincarnation impossible) and Earth exploited to their benefit, that the "Galactic Union" is taking great measures to fend them off until we are able to defend ourselves, that aliens are not going to reveal themselves, because in the past such events started a few religious cults (which are the sources of religion on our planet, and that our planet is the only one on which religion ever happened -- everyone else just *knows* that reincarnation is happening, because they're *experiencing* it), and that the US government (or rather: whoever runs the government) is planning a *fake* "alien invasion", using their own half-baked UFOs to attack the Earth (and then take over all the armies of the world to "fend off" the fake attack, and then create a worldwide regime) -- as of the last one, I wouldn't be surprised -- the ground is already being prepared, see all the /. threads about surveillance, taking away our freedom, etc.

    My opinion: even if this is bullshit, every good lie has a kernel of truth in it. I'm going to sit and observe, and take action if some of the things that that (supposed) alien is claiming would turn out to be true.
  • Re:To prove it... (Score:4, Interesting)

    by geckipede (1261408) on Tuesday November 18, 2008 @12:52PM (#25803195)
    "My opinion: even if this is bullshit, every good lie has a kernel of truth in it." The only thing with even a ghost of truth in that is that you can measure the sun's contribution to global warming by looking at temperatures and/or reflected light from other worlds. This has been done. The sun's output is very close to constant.
  • Re:To prove it... (Score:3, Interesting)

    by severoon (536737) on Tuesday November 18, 2008 @07:04PM (#25809863) Journal

    There is no evidence [of] the existence of god. I'm with you so far.

    There is no evidence [of] the nonexistence of god. Even if we accept that this is an accurate statement about the beliefs of atheists—which I do not think it is—this still doesn't make atheism a religion.

    Your error lies in the assumption that the existence of god is akin to flipping a fair coin. If a coin is flipped and the result is concealed by placing it under a hat, for example, it is reasonable to assume that the coin is in one of two states: heads or tails. You have no evidence of heads and no evidence of tails, therefore to commit to one position or the other is equally unfounded, regardless of whether you turn out to be correct.

    The example of the coin is different than the existence of god, however; specifically, in the case of the coin, you have knowledge about the context of the outcome...you know the result will be one of two outcomes. Postulates about the existence of god, however, are context-free. There can be no context whatsoever that may "contain" god—if we accept the usual definition of god as an omniscient, omnipotent being, then, by this definition, there is no possible context in which god can be placed. We know nothing about the possible outcome if god were to exist.

    Imagine if I were to assert there is an undetectable green basketball that always hovers next to my head. I could dismiss the lack of evidence for the existence of such a thing by simply pointing out that it is undetectable, and therefore the universe is necessarily devoid of supporting evidence. You would deny that assertion on the basis that there is no proof of it. Furthermore, I expect you would not simply deny my assertion, but that you would make an assertion of your own: that there is no undetectable green basketball hovering next to my head. Because of the arbitrary nature of my positive assertion, your negative assertion about the ball's existence is far more reasonable...in fact, it is similar if not the same as the simple denial of my assertion. Your error is in treating a negative assertion as though it were simply one of a set of alternatives, all of which are well-situated in a known context.

    If we follow your line of thinking, then you would simply abstain from forming any opinion about the existence of the undetectable green basketball, and in doing so you must necessarily accept the possibility of its existence. You would not agree with my assertion that it's there, nor would you assert that it is not there; you would be forced to simply accept that you do not know. The relevant bit, though, is that you would essentially be admitting the possibility of its existence. In other words, your way of thinking leads to one result: you must necessarily allow for the possibility of each statement in the set of all possible undisprovable statements. Furthermore, you would ostensibly regard each statement in this set as not only possible, but with equally likely as not.

    The interesting result about this erroneous approach is the total logical paralysis it causes if followed to its natural end. If at some point you care to make an assertion I don't wish to accept, regardless of whether it is provable or not, I can set about frustrating every possible proof you can propose by forcing you to admit ignorance of a relevant but undisprovable possibility that is in direct conflict with your assertion. You can't even argue based on the likelihood of whatever absurd statement I care to make, because as mentioned at the end of the last paragraph, you have no reason to regard its truth or falsity with anything other than 50-50 likelihood.

    So, it is not only correct, but also practical to recognize that atheism is most definitely not a belief of a religious nature. The way of thinking that you propose is appropriate to situations like the coin flip, where the context of the set of possible results is understood. Indeed, in the case of a flipped coin concealed under a hat, it would be ludicrous to commit to belief in heads or tails specifically because the context of the set of possible results is understood.

COBOL is for morons. -- E.W. Dijkstra

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