Where does earths water originally come from?

Answer 1

The Short Answer:

Some of it was here when the earth was made (but locked into the rocks as hydrates ... much of that released as the Earth became molten.)

And some came from comets and other ice particles that have bombarded the Earth since it was formed.

No one knows which part was the major contributor.

In more depth...:

At some early point in time (after the moon) the Earth was a hot, glowing ball which would have out-gassed fairly completely. Hydrogen is light enough so that most of it would have escaped. Free Hydrogen is lost from a planet as small as Earth, it takes the outer gas giants with much stronger gravitational pulls to hold it Additionally, there was little or no oxygen (all the bound oxygen was in the rocks - which is mostly still there).

One common theory of where the Earth's water comes from was the comet impact theory. The belief was that earths water came from comets that impacted on the early Earth (recall that at this time there would be no atmosphere to disintegrate the comets). Scientists have looked at samples of ice from comets and the ratios of heavy water (water with an isotope of hydrogen called deuterium) does not match the water found in the oceans. This has lead scientist to believe the oceans are not made up of mostly cometary water.

Evidence of water on the early Earth comes from Zircon Crystals dating from 4.53 billion years ago, only about 200 million years after the planet formed. Zircon crystals can only be created in the presence of water. This has lead scientist to believe that a large percentage of water was already in the rocks on Earth when it was created.

However examination from "fossil water" taken from Hawaiian volcanoes that originally comes from the bottom layers of the crust also shows differences from modern water.

A final note:

The following is a quote from the founder of Ask an Astronomer, Dave Kornreich:

No, H20 cannot exist in stars, but H and O separately can. Hydrogen is the basic building material of the universe, created in the Big Bang. Oxygen is created by nuclear reactions in stars. If you put H and O together in the cold of space, you get H2O. There are enourmous amounts of water in space. In fact, nearly all of the oxygen in space is in the form of water or carbon monoxide. Similarly, most the carbon and nitrogen in space are also in their most hydorgenated forms: methane (CH4) and ammonia (NH3).

Answer 2

There are a number of different hypotheses about the source of the Earth's water, but I believe that the water on our planet was brought by comets. Earlier in the Earth's history, comets collided with the Earth and comets contain a large amount of ice.

Answer 3

rain!

Answer 4

GOD made it ALL!

As of 2007 the Order to test ALL that the Atheists had paid to be made-up to look like their claims, beliefs, was finished! It was lots of Scientists that discovered that Everything that the Atheists had used are Fakes! The Majority of what the Atheists had used and claimed to be "millions of years old fossils" were discovered to really be New BONES! And all from already know of animals! All of their fake animals, like their caveman, were made-up with BONES and fossils all from already known of animals and not one fossil dated to be more then six thousand years old! Same date as The Bible states we are!

A Federal Law was soon passed that requires all Atheism removed from all the public schools in the USA! Some states were very fast here! Some are being poky.

Atheism has been scinctificly proven to be a "religion" with Zero proofs that are honest!

GOD made ALL!

Answer 5

ur mother c;