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Asteroid Crashes Likely Gave Earth Its Water

Posted by samzenpus on from the space-water dept.

Diggester writes "Asteroids from the inner solar system are the most likely source of the majority of Earth's water, a new study suggests. The results contradict prevailing theories, which hold that most of our planet's water originated in the outer solar system and was delivered by comets or asteroids that coalesced beyond Jupiter's orbit, then migrated inward."

11 of 138 comments (clear)

  1. Sounds intelligently Designed by gameboyhippo · · Score: 3, Funny

    So rocks carrying massive amounts of water magically came to the Earth?

    1. Re:Sounds intelligently Designed by Tukz · · Score: 4, Informative

      Frozen rocks basically, but yes.
      They slammed into earth.

      Watch some Discovery or read some books some times.
      This is nothing new.

      What may be new, is the fact that these asteroids may be from further away than first anticipated.

      --
      - Don't do what I do, it's probably not healthy nor safe. -
    2. Re:Sounds intelligently Designed by Black+Parrot · · Score: 3, Funny

      So rocks carrying massive amounts of water magically came to the Earth?

      Yes, and the Intelligent Designer's son turned some of it into wine.

      --
      Sheesh, evil *and* a jerk. -- Jade
    3. Re:Sounds intelligently Designed by amck · · Score: 3, Informative

      Some people call it gravity.

      Note: Earth has about 0.1 - 0.01 % water by mass (depending on how much water you think there is in the mantle). Compared to the outer solar system (typically 50%) it's not _that_ massive.

      --
      Anyone who believes exponential growth can go on forever in a finite world is either a madman or an economist
    4. Re:Sounds intelligently Designed by tragedy · · Score: 3, Funny

      If you consider gravity to be "magic", then yes.

    5. Re:Sounds intelligently Designed by dryeo · · Score: 3, Interesting

      Better yet, crash Ceres into Venus. A 9.43 ± 0.07×1020 kg mass crashing at 10 miles per second would probably blow most of the atmosphere off and Ceres is largely water.

      --
      https://en.wikipedia.org/wiki/Inverted_totalitarianism
  2. It's Turtle piss, mostly. by Grog6 · · Score: 5, Funny

    The four Elephants contributed a lot less.

    Humanity's very existence is proof against Intelligent Design.

    --
    Truth isn't Truth - Guliani
  3. Re:How did the water get on the asteroids? by MightyYar · · Score: 5, Informative

    It looks like a lot of water, but it's mostly on the surface so it is misleading. Here's a neat graphic.

    --
    W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
  4. Re:Just my own musings... by Black+Parrot · · Score: 3, Insightful

    If I was the creator of the universe, and had billions of trillions of planets capable of supporting life, what would be the most efficient 'delivery system' for me to use to deliver the "Seeds of Life" to them all?

    If you can create universes, you don't need "delivery systems". You just speak your will into being.

    --
    Sheesh, evil *and* a jerk. -- Jade
  5. Re:The moon by tragedy · · Score: 3, Interesting

    The moon has lower gravity than earth and little or no atmosphere for all of its history. Any water on the surface of the moon would be expected to be stripped away by by the solar wind over millions of years, leaving only deposits in shielded locations. Some water would also be created on the moon from the solar wind as well. I think we should reasonably expect with those conditions and that amount of time that the concentrations of water on Earth and on the moon would be nothing alike.

  6. Yes, it would by F69631 · · Score: 5, Informative

    According to quick Google, average depth of oceans is about 4km, surface area of earth is about 510'072'000 km2 and water covers about 70% of earths surface.

    5.1E8 km2 * 4km * 0.7 = 1.428 billion km3. Sphere of that volume is about 1396 km across.

    The GP's graph says "1390 kilometres across and has a volume of 1.4 billion cubic kilometres", which is very close to that quick approximation.

    My approximation is very quick and dirty (I didn't take into account that surface of earth is less 4km below the surface than on the surface, which would reduce the sphere... but I also didn't take into account glaciers, etc. which would increase the sphere... Obviously the surface of sea isn't exactly 70% and the depth isn't exactly 4km...) but I feel very confident that the scale of the number is about right and it happens to perfectly match the graph.