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Origin Of Water
Water covers some 71% of the earths surface- (approx 326 million cubic miles- that's 326 million trillion gallons) which leads me to wonder how was water formed initially? Where did it come from, and how did it get to earth? How did it become formed in such huge quantities to fill the oceans, which contain 96% of the water? And why aren't any other planets formed the same way as earth, and appear to be waterless?
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Thanks elliemay- that's an interesting little article, but it doesn't explain how water actually got there to start with, it simply says it was there at the beginning, and can be found in the mantle below the earths crust. The comets and asteroids theory is crazy, and very unlikely to explain the enormous quantities or why no other planets seem to have been similarly bombarded.
It also depends on the ability to retain the water after collision. Venus can't, because it's far too hot, and therefore all water that did exist will have long since evaporated. Mars' gravity is, I think, usually held to be too weak to retain an atmosphere, so again there would be little to stop most (if not all) water escaping.
Uranus and Neptune both have a great deal of water in the form of ice. Several moons of Jupiter and Saturn also have a lot of water.
I think, in the end, the comet origin theory is the best-supported.
Uranus and Neptune both have a great deal of water in the form of ice. Several moons of Jupiter and Saturn also have a lot of water.
I think, in the end, the comet origin theory is the best-supported.
Thankyou aelmpvw- that's also an interesting read from the Smithsonian. The writer started well, but it is very unconvincing- he basically debunks the first theory and reckons it is probably the asteroid version-
"But Earth’s early history, including epochs with high ambient temperatures and no enveloping atmosphere, implies that surface water would have evaporated and drifted back into space. The water we encounter today, it seems, must have been delivered long after Earth formed."
But that doesn't explain the sheer quantity of water, and why it wasn't delivered to other planets in the same way. I am really surprised that science can't explain it!
"But Earth’s early history, including epochs with high ambient temperatures and no enveloping atmosphere, implies that surface water would have evaporated and drifted back into space. The water we encounter today, it seems, must have been delivered long after Earth formed."
But that doesn't explain the sheer quantity of water, and why it wasn't delivered to other planets in the same way. I am really surprised that science can't explain it!
Thanks Jim360- that's very helpful regarding ice on other planets- thanks for pointing it out. I do find it difficult to see that the asteroid theory is plausible though. Balz Kamber, chair of Geology at Trinity College makes a point by saying "But recent research has made this captured water hypothesis seem much less likely.
In January 2017, a study showed that the type of ruthenium (one of those iron-loving metals) in Earth's mantle has a different atomic signature to that found in common asteroids from the outer solar system.
That suggests the late veneer came from the inner solar system, where volatile substances are rare – and that these asteroids therefore weren't the main source of water on Earth.
This adds to other research that suggests water was abundant on Earth before the late veneer is thought to have arrived.
For example, there is various evidence that the oldest terrestrial minerals (zircon) crystallised from magma sources interacting with liquid water. These minerals are between 4.1 and 4.3 billion years old, but the final late veneer is most commonly thought to have been delivered around 3.9 billion years ago.
What's more, just because an asteroid carries water doesn't mean it can successfully deliver this cargo to Earth."
It's a fascinating thought to consider how on earth (excuse the pun) water got here in the quantity it has done.
In January 2017, a study showed that the type of ruthenium (one of those iron-loving metals) in Earth's mantle has a different atomic signature to that found in common asteroids from the outer solar system.
That suggests the late veneer came from the inner solar system, where volatile substances are rare – and that these asteroids therefore weren't the main source of water on Earth.
This adds to other research that suggests water was abundant on Earth before the late veneer is thought to have arrived.
For example, there is various evidence that the oldest terrestrial minerals (zircon) crystallised from magma sources interacting with liquid water. These minerals are between 4.1 and 4.3 billion years old, but the final late veneer is most commonly thought to have been delivered around 3.9 billion years ago.
What's more, just because an asteroid carries water doesn't mean it can successfully deliver this cargo to Earth."
It's a fascinating thought to consider how on earth (excuse the pun) water got here in the quantity it has done.
Ok so a lot was formed initially in the mantle, some added later by comets etc. So spungle seems concerned with how the water got their in the first place. Well H2O is the "ash" when Hydrogen is burned when oxygen is present. Plenty of hydrogen about and the Oxygen is formed by nuclear fusion in stars thus a second generation solar system like ours would have plenty of the raw material for water formation thus water is found all over the solar system. Planets like Mercury and Venus have long lost their but moving out water is plentiful.
Peter Pedant //...we arent going to get
and so water must have been put there by God,
are we ?//
Which still leaves us with the question of "How 'He' dunnit?"
Did it come out of 'His' . . . oh, nevermind.
https:/
and so water must have been put there by God,
are we ?//
Which still leaves us with the question of "How 'He' dunnit?"
Did it come out of 'His' . . . oh, nevermind.
https:/
-- answer removed --
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