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Earth Science

Meteorite Study Suggests Earth May Have Been Wet Since It Formed 59

Posted by BeauHD from the contrary-to-popular-belief dept.
nickwinlund77 shares a report from Phys.Org: A new study finds that Earth's water may have come from materials that were present in the inner solar system at the time the planet formed -- instead of far-reaching comets or asteroids delivering such water. The findings published Aug. 28 in Science suggest that Earth may have always been wet.

Researchers from the Centre de Recherches Petrographiques et Geochimiques (CRPG, CNRS/Universite de Lorraine) in Nancy, France, including one who is now a postdoctoral fellow at Washington University in St. Louis, determined that a type of meteorite called an enstatite chondrite contains sufficient hydrogen to deliver at least three times the amount of water contained in the Earth's oceans, and probably much more. Enstatite chondrites are entirely composed of material from the inner solar system -- essentially the same stuff that made up the Earth originally. "Our discovery shows that the Earth's building blocks might have significantly contributed to the Earth's water," said lead author Laurette Piani, a researcher at CPRG. "Hydrogen-bearing material was present in the inner solar system at the time of the rocky planet formation, even though the temperatures were too high for water to condense."
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Meteorite Study Suggests Earth May Have Been Wet Since It Formed More

Meteorite Study Suggests Earth May Have Been Wet Since It Formed

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  • Neon (Score:3, Interesting)

    by ShanghaiBill ( 739463 ) on Friday August 28, 2020 @03:18AM (#60448712)

    Most scientists believe that Earth lost her water during the collision with Theia [wikipedia.org], and then later gained water again from comets and asteroid impacts.

    A strong piece of evidence for this is the near-total absence of Neon on Earth. Neon is common in the Universe and in the rest of the Solar System. But if the post-collision Earth was too hot to hold onto Neon (atomic weight: 20) it would have also been too hot to hold onto water (molecular weight: 18). Ergo, the water came later.

    • Re:Neon (Score:4, Interesting)

      by Sique ( 173459 ) on Friday August 28, 2020 @05:35AM (#60448848) Homepage
      As Neon is lighter than N2, it would also today go up into the atmosphere and leave Earth, not as fast as Helium though, but after 4.5 billion years, there is not much Neon left. So I doubt the "Neon mainly got lost in the Theia impact" hypothesis a little. Additionally, in the heat as strong as after a strike with a planet the size of Mars, not many molecules would be left, the atmosphere would probably turn into a plasma. But apparently, Earth didn't lose its Nitrogen during the event, though atomic Nitrogen is even lighter than Neon.

      • But apparently, Earth didn't lose its Nitrogen during the event

        Maybe it did. Nitrogen is rare on Earth. We only think it is common because we are surrounded by it, but the atmosphere is just a tiny wisp when compared to the bulk of the planet. Oxygen also exists in the atmosphere, but 99.99% of it is in the oceans and lithosphere. But with nitrogen, the atmosphere is almost all there is.

        • Re: (Score:3)

          by Sique ( 173459 )
          While in the Solar System, the relative content of Neon (3.4 * 10^6) is about equal to Nitrogen (3.7 * 10^6), on Earth, it's not (5.0 * 10^-3 vs. 3.0 * 10^2). If Neon were lost on Earth mainly in a single event, when Nitrogen would also be lost, then they should remain about equal. But Earth has only about one hundred thousandst of Neon compared to Nitrogen, which points to a process that loses Neon with much higher probability than Nitrogen, and that would happen if the temperature on Earth was low enough

      • Re: (Score:2)

        by Bengie ( 1121981 )
        Not criticizing, just trying to better understand, but wouldn't atomic nitrogen be almost impossible? Atomic nitrogen is extremely reactive and forms crazy strong bonds when it does react. Neon on the other hand is a noble gas and pretty much doesn't react with anything to form any molecules.

    • the near-total absence of Neon on Earth

      Ok so explain my neighbors "Tig ol' Bitties" man-cave sign, smart guy.

    • But if the post-collision Earth was too hot to hold onto Neon (atomic weight: 20) it would have also been too hot to hold onto water (molecular weight: 18). Ergo, the water came later.

      Just from the atomic and molecular weight, the conclusion seems logical, until you realize that water has entirely different properties, not being inert, being a dipole, etcetera. If water has evaporated and blown off, you can (likely) make the conclusion that neon would also have, but the other way around is not a given.

    • Most scientists believe that Earth lost her water during the collision with Theia, and then later gained water again from comets and asteroid impacts.

      That is one of the theories in consideration, but if you actually read the current science (drinking from the firehose, I know) you'll find that it's a lot further from a consensus than you imply.

      Theia (or something similar) does appear a lot, but the details of the collision are much more unsure. Certainly, gravitational potential energy became heat, but whe

  • Moist.

  • Mother Earth has been horny all along.

  • ...says "No Thanks!" and boards a Falcon 9 to Mars.

  • i've certainly been.....

  • Anything will get her wet! She's been wet since she was born!

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