Earth's Water Didn't Come From Outer Space

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."

Comments

it would be too nice to be true

[Anonymous Coward]

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:it would be too nice to be true

[Requiem18th]

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

Re:it would be too nice to be true

[Urkki]

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:it would be too nice to be true

[a_hanso]

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)

It is just way more complicated actually

[Framboise]

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.

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Re:Hindu Historians answered water-Planet Lucifer

[PseudonymousBraveguy]

Whatever drug you are taking, take less. Or much more.

Also, I can't resist citing my favorite xkcd quote: "While the author's wildly swerving train of thought did at one point flirt with coherence, this brief encounter was more likely a chance event than a result of even rudimentary lucidity"

Re:Um...

[Chris Burke]

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!"