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Earth Space Science

Earth's Water Didn't Come From Outer Space 181

Posted by Soulskill from the no-word-on-elvis dept.
sciencehabit writes "Where did Earth's oceans come from? Astronomers have long contended that icy comets and asteroids delivered the water for them during an epoch of heavy bombardment that ended about 3.9 billion years ago. But a new study suggests that Earth supplied its own water, leaching it from the rocks that formed the planet. The finding may help explain why life on Earth appeared so early, and it may indicate that other rocky worlds are also awash in vast seas."
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Earth's Water Didn't Come From Outer Space More

Earth's Water Didn't Come From Outer Space

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  • Um... (Score:1, Funny)

    by Anonymous Coward

    Isn't the earth in outer space?

    • Re:Um... (Score:5, Informative)

      by Zero__Kelvin ( 151819 ) on Tuesday November 30, 2010 @06:11AM (#34386672) Homepage
      Um ... By definition, no.

    • Isn't the earth in outer space?

      The definition [wikipedia.org] of outer space is

      the void that exists beyond any celestial body including the Earth.[1] It is not completely empty (i.e. a perfect vacuum), but contains a low density of particles, predominantly hydrogen plasma, as well as electromagnetic radiation, magnetic fields, and neutrinos. Theoretically, it also contains dark matter and dark energy.

      So no, the Earth isn't in outer space. But neither is water. It's a void.

      The headline "Earth's Water Didn't Come From Outer Space" should get a resounding "duh!" from the Slashdot crowd.

      • Re:Um... (Score:4, Insightful)

        by Chris Burke ( 6130 ) on Tuesday November 30, 2010 @12:05PM (#34390372) Homepage

        So no, the Earth isn't in outer space. But neither is water. It's a void.

        Of course the earth is in outer space. It doesn't have to be outer space to be in outer space. Oceans are large bodies of salt water, but you can be in the ocean without being salt water. Your Xbox360 came in a cardboard box, even though the definition of 'cardboard box' would explicitly exclude the Xbox360 from being part of it.

        If you're surrounded by the void, then you're in the void. The earth is in outer space.

        Then again maybe I should get a resounding "whoosh!"

        • Seems like this might be fun to debate, just for the heck of it....

          Without citing references, I'll state that Outer Space was first named and defined in an Earth-centric fashion. Go far enough away from the Earth, and you get to Outer Space. It's that area past the Troposphere, past the Stratosphere, past the Mesosphere, past the Thermosphere, past the Exosphere. As Wikipedia says, "These are the boundaries between the earth's surface and outer space."

          By definition, outer space is the area between planet

          • By definition, outer space is the area between planets and other celestial objects.

            By your analogy, Maui could be considered "in the ocean". By definition, the ocean excludes land,

            You're still confusing "in" with "is".

            Maui is in the Pacific Ocean. That is 100% correct.

            The reason people don't say you're in the ocean when you are standing on the island is because, while in some sense it is true, it's not the most relevant context. You are not directly surrounded by the ocean, you're surrounded by something

            • Just read the post from Chapter80 and learn something.

              • I did, and all I learned is that multiple slashdotters don't understand that "is" and "in" aren't the same.

                And that the same source that they rely on to verify that the earth isn't space also confirms that the earth is in space, but are happier leaping to their illogical conclusions based on ill-informed pedantry.

                • No. What you learned is nothing, because you haven't figured out basic math yet, or the definition of Outer Space. You also haven't figured out that if you subtract a geometric region from a larger geometric region, you don't get more area as a result.

                  • No. What you learned is nothing, because you haven't figured out basic math yet, or the definition of Outer Space.

                    Lol, I think you need to brush up on the definition of outer space yourself, and the definition of the terms used in that definition. You have to know the meaning of multiple words to actually understand what's going on here.

                    You also haven't figured out that if you subtract a geometric region from a larger geometric region, you don't get more area as a result.

                    How foolish. The area of the dough

                    • The "area" of a three dimensional donut doesn't make any sense to me unless you're talking about surface area. Or I guess cross-sectional area, but that'd be an even weirder thing to call "area" with no qualification since it depends what cross section you're taking what happens.

        • You are confusing the word "in" with the phrase "surrounded by". Outer Space is all of the space which the Earth and it's atmosphere are not in, by definition. This isn't open for debate. It has to do with understanding the English language, and the definition of "Outer Space".

          • You are confusing the word "in" with the phrase "surrounded by". Outer Space is all of the space which the Earth and it's atmosphere are not in, by definition. This isn't open for debate. It has to do with understanding the English language, and the definition of "Outer Space".

            You're right, there is no debate which is why you'll find many places discussing earth in space [ncsu.edu].

            It's why WP says on the Outer Space page that "Outer space (often simply called space) is the void that exists beyond any celestial body",

            • You got it wrong at every turn. By definition, the term Outer Space, a term in the English language, refers to all the space in the universe that is not the Earth and it's atmosphere. Outer Space = The Universe - The Earth and it's atmosphere.

              "Look at your post -- your only argument that earth is not in space is that earth isn't space. Which is as ridiculous as saying that the USS George Washington isn't in the ocean because it isn't the ocean."

              No. What I am saying is that by definition the Earth and it'

              • You got it wrong at every turn. By definition, the term Outer Space, a term in the English language, refers to all the space in the universe that is not the Earth and it's atmosphere. Outer Space = The Universe - The Earth and it's atmosphere.

                Wow. Once again you state the uncontested claim that the Earth isn't Outer Space, and then without even acknowledging it you equate "is" with "in", so "isn't" means "not in", expecting the completely unsupported conclusion to be obvious.

                Yet by definition the earth is

                • I just realized that we are both right. I live on the planet Earth, but clearly you live in Outer Space.

                  Plonk [wikipedia.org]

                  • So... is that your way of avoiding clicking on the link and realizing that you're wrong, by definition? Or is it that you've already had to admit it to yourself, so now you're mad at me?

                  • You can ignore me and ignore the links that prove you wrong all you want, they won't go away. Which you know, which is why you're mad. But maybe once the hurt has passed, you'll realize you've learned something in spite of yourself.

                    • Wow, how did that end up a triple post? Me fail.

                    • Yes, because I thought people being that stupidly pedantic would want to actually read something contrary to their stupidity. A big mistake I admit.

    • The rocks that formed the Earth certainly were from outer space.

      The Earth's upper atmosphere is bombarded with water every second. This is a known fact, so I don't know where these scientists are coming from. It's not likely, IMHO, that these scientists are even remotely close, because we have a lot of water here on Earth.

      • Without the Earth there is no Outer Space. Before the Earth there was no Outer Space. You are confusing "Outer Space" with the Universe. Outer Space = The Universe - The Earth and it's atmosphere. Holy shit, I can't believe people are having trouble understanding this simple concept, even on Slashdot.

    • Yes - but if you have a tap inside your house hooked up to a water supply also inside. You pour a cup of water from the sink - you wouldn't really say "I got this from outside" when you are inside your house. Technically, yes, your house is within the realm of outside, but people would be under the impression you left your house to acquire water.

      Same thing here with inner space versus outer space - did the water from from within?

  • it would be too nice to be true (Score:5, Insightful)

    by Anonymous Coward on Tuesday November 30, 2010 @05:22AM (#34386444)

    If this is true, then most earth sized rock planets in the habitable zone are also having water by default. Whoa, this simplifies the drake equation.

    • Re: (Score:3, Insightful)

      by Requiem18th ( 742389 )

      This makes The Habitable Zone into The Really Very Habitable More Like Life Sprouting Zone.

      • Re:it would be too nice to be true (Score:4, Insightful)

        by Urkki ( 668283 ) on Tuesday November 30, 2010 @06:54AM (#34386854)

        This makes The Habitable Zone into The Really Very Habitable More Like Life Sprouting Zone.

        Not really.

        For example, it may be that what was once much thicker crust, and is now Moon, would have contained the water, and there would be only dry surface, slowly seeping water vapour into the atmosphere, where it would be promptly broken down by Sun and hydrogen escaping.

        We really have no idea, no big picture. We have just one sample, and even though we're literally standing on it, we don't even know how things went that fourish billion years ago.

        • Re: (Score:3, Insightful)

          by account_deleted ( 4530225 )
          Comment removed based on user account deletion

          • The way it was formed is pretty unique

            I take it you have some evidence that it was "pretty unique", as opposed to "fairly common"? If our solar system is any guide, it happens to 1/4 of all rocky planets....

            • Re: (Score:2)

              by mcgrew ( 92797 ) *

              None of the other non-gas giants has a moon anywhere near as big as our satellite. Asimov explored this in Foundation and Earth, where the Earth was fairly unique in the galaxy.

              Also, tidal forces probably played a part in the development of life. I think it's more likely that if we find extraterrestrial life, we'll find it on the satellite of a gas giant, not in a rocky small planet.

              The Forgosts think that too [slashdot.org] (of course, I made them up ;)

              • None of the other non-gas giants has a moon anywhere near as big as our satellite. Asimov explored this in Foundation and Earth, where the Earth was fairly unique in the galaxy.

                So, Mercury, Venus, Earth, Mars. One has a large moon. Which is pretty close to 1/4 of them.

                Thar only 1/4 of our four samples has a large moon in no way implies that that one sample is "fairly unique in the galaxy".

                Also, tidal forces probably played a part in the development of life. I think it's more likely that if we find extra

    • Re: (Score:2, Insightful)

      by a_hanso ( 1891616 )

      Agreed.

      a) Hydrogen is the most abundant element in the universe
      b) Oxygen is also highly abundant: plenty of it is created in stars (en.wikipedia.org/wiki/Stellar_nucleosynthesis)
      c) Oxygen happens to be highly reactive
      d) Given their abundance, we can be sure that most planets will have the two elements, even if only as components of minerals

      Now all you need is some sufficiently energetic process (thermal?) to release the two and react, and you've got an ocean (if the temperature is right)

      • That would be why, AFAIK, water is the most common compound in the universe. From what I understand, Hydrogen and Oxygen are the two lowest elements on the periodic table which can react with each other. I tried to confirm that just now, but failed - I'd appreciate some confirmation from someone with a better grasp of chemistry :)

    • Whoa, this simplifies the drake equation.

      While I am as excited as you are at the possibility of finding extraterrestrial life, I must point out that the drake equation is and will always be meaningless. I'm going to quote Michael Crichton and T.J. Nelson here because I couldn't say it any better myself:

      The Drake equation consists of a large number of probabilities multiplied together. Since each factor is guaranteed to be somewhere between 0 and 1, the result is also guaranteed to be a reasonable-looking number between 0 and 1. Unfortunately,

  • when they're prolly going to announce that a water-ice meteorite had been discovered, that also brought extraterrestrial life with it.

    NASA press release [nasa.gov]

  • Not Invented Here - NOT (Score:4, Interesting)

    by G3ckoG33k ( 647276 ) on Tuesday November 30, 2010 @06:04AM (#34386638)

    Not Invented Here - NOT

    This news goes in hand with the parsimonious explanation that the Earth is the endogenous source of life, too.

    I habitually distrust news that relate any process on Earth as influenced by Venus, Mars, or 'Outer Space'. Remember what a fool they made out of Bill Clinton with the 'bacteria from Mars'...

    Invented Here - YES!

  • It is just way more complicated actually (Score:5, Insightful)

    by Framboise ( 521772 ) on Tuesday November 30, 2010 @06:12AM (#34386676)

    The water we drink must have been reprocessed many times for eons by living beings.
    Remember that the amount of sedimentary rocks made of dead stuff is much larger than
    the total of oceans. This implies that striclty speaking each molecule has been dissociated
    and recombined with different oxygen and hydrogen atoms. Many O and H atoms now in
    water have been in other compounds (CO, H2SO4, ...) for a while and vice versa.

    • Re: (Score:3, Funny)

      by Anonymous Coward
      I knew hydrogen was a slut, I just didn't know it was to this extent. And to think he said he loved me and only me.... now I see he has been seeing Carbon and even sulfur...sulfur for crying out loud!


      Yours sincerely, Oxygen

    • This implies that striclty speaking each molecule has been dissociated
      and recombined with different oxygen and hydrogen atoms.

      Actually, liquid water is a constantly changing mixture of H20 molecules, H+ ions and H3O- ions. The hydrogen atoms are continuously shifting between different molecules and ions, in proportions depending on the pH of the sample. No particular group of atoms in liquid water stays together for very long.

  • can't tell by the inhabitants (Score:3)

    by dltaylor ( 7510 ) on Tuesday November 30, 2010 @06:37AM (#34386774)

    Seems to be that a very high proportion of the "ugly bags of water" (ST:TNG) infesting the surface must have come from "outer space", in the colloquial sense.

  • Could the water have been formed by hydrogen in the early Earth combusting and forming water (or similar natural means)?

    • Where do you get the oxygen? Most of it in the protoplanetary disk would have already encountered hydrogen (being 75% of the stuff there) and made water.

  • Creations claiming that this paper is talking about the Fountains of the Deep [answersingenesis.org] and science has proved the Flood in
    3
    2
    1...

  • Of course it did (Score:3, Interesting)

    by joeyblades ( 785896 ) on Tuesday November 30, 2010 @08:56AM (#34387614)
    Everything that exists on this planet was the output from stars. Therefore, everything on Earth came from outer space, including it's water. The only question is when did the water arrive relative to the majority of the other star debris.

    • The only question is when did the water arrive relative to the majority of the other star debris.

      Right. The main question is: Did it arrive after there was an Earth, or was it already part of the accretion disk material that eventually coalesced into the planet. If it was already here, then Earth's water didn't come from anywhere, it was already present at the moment in time at which one could meaningfully say "Earth's" anything.

      So what you're saying is technically correct in one sense. However the stat

  • RTFA (Score:4, Informative)

    by mdsolar ( 1045926 ) on Tuesday November 30, 2010 @09:02AM (#34387670) Homepage Journal
    Reading the conclusions of the fine article, I notice "...the more probable source for early water oceans [on Earth] is the collapse of the planet's steam atmosphere..." and "... these oceans may not persist over billions of years on smaller planets against the processes of atmospheric escape and continuing impact blow-off..."

    It is a clue also that the title is about early oceans. This paper has nothing to do with the origin of Earth's present oceans but rather discusses early, pre-bombardment phase water and also more massive rocky planets.
  • Early on when the earth was just starting out, there was all sorts of rocks, dust, planetoids and other debris floating around the solar system. As stuff slammed into the earth, it's mass increased. It "sucked in" more and more debris which gave it more mass: omnomnomnom > more mass > omnomnomnom > more mass... etc, etc. The frequency of and size of debris constantly pummeling the earth created an immense amount of heat. The heat created a bubbling lava-like ooze that covered the
  • The whole water from the large bombardment period never really made that much sense to me. It always seemed like grasping at straws. The idea that water/ice was either in rocks, or just part of the mass that coalesced into the earth makes far more sense. There is water vapor in Saturn's rings, so why wouldn't there be water vapor in the dust cloud the earth formed from?

    • The whole water from the large bombardment period never really made that much sense to me. It always seemed like grasping at straws.

      Before waiving your hand in dismissal, perhaps Your Exellence would consider investigating the D/H isotopic ratio of the oceans, and how they compare with the cometary one- a possible correction for long-term exposure to cosmic rays may also apply.

      Btw it's called 'science', and 'working with evidence'.

  • Water leaching from rocks makes sense if there is a motive force such as bacteria digesting rock. There's a whole lot of eating going on.

    • Water leaching from rocks makes sense if there is a motive force such as bacteria digesting rock. There's a whole lot of eating going on.

      Ewwww. Ich. Are you saying that the nice white beach is bacterial doo-doo?

      That's it! I'm staying in the basement!

      (Returning to reality a bit, you might consider physical and chemical forces first, no need to invoke your furry little colonic friends.)

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