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Monday, 4 May 2015

The origin of water

One of the big scientific questions is the origin of water on planet Earth. Seriously. This blog topic suddenly came up while watching some other TED videos.  I then noticed a reference to a TED video called "Where did Earth's water come from?" by Zachary Metz. Mr Metz basically offers two explanations: (1) ice bearing comets hitting Earth or (2) asteroids - containing H2O molecules - bombarding Earth.

Strangely enough another hypothesis is missing.

Water is made of two hydrogen atoms attached to an oxygen atom. Theoretically, it's possible to mix them but it would be an extremely dangerous process. Since hydrogen is extremely flammable and oxygen supports combustion, it wouldn't take much to create this fusion. Pretty much all we need is a spark - not even a flame - and boom! We've got water. But we also have an explosion and, if our experiment was big enough, a deadly one. The Hindenburg zeppelin was filled with hydrogen to keep it afloat. In 1937, static electricity caused the hydrogen to spark. When mixed with the ambient oxygen in the air, the hydrogen exploded, turning the Hindenburg in a ball of fire that completely destroyed this large airship within half a minute. This explosion also created a lot of water. (source)

In 2014, new geological research showed that deep within the Earth's rocky mantle, lies oceans' worth of water locked up in a type of mineral called ringwoodite. Ringwoodite is a mineral that can trap water in its molecular structure and is formed under high pressures and temperatures, such as those inside our planet. These building blocks of water are bound up in rock located deep in the Earth’s mantle, and in quantities large enough to represent the largest water reservoir on the planet, according to the research. The surface water we have now came from degassing of molten rock. It came from the original rock ingredients of Earth. (link 1, link 2, link 3)

In March 2014, that same research group found a unique diamond from the Earth's mantle that was packed in ringwoodite containing water. Until then ringwoodite specimens were either collected from meteorite material or created in the laboratory. (link 1link 2link 3) Apparently, scientists had always assumed that ringwoodite was an "alien" mineral. Hence, the theory of Mr Metz above.

If the Earth's and "alien" ringwoodite both contain water then there may be another hypothesis: a planet's core is like a chemical factory. As all planets are likely to be formed along the same way, then it is also likely that most - if not all - planets store huge amounts of water in their core. The ringwoodite bearing "alien" asteroids would then just be evidence of such an hypothesis.

When you stand on one side of the Grand Canyon then you cannot but realise that there must have been much more water on our planet, a long time ago. That water has either evaporated (by lack of an atmosphere back then), or was sucked into the Earth's core to prevent the chemical factory from overheating and exploding, or both. Earth's original water may now be found in ringwoodite. That cooling off is likely to have resulted in the various Ice Ages for which three main types of evidence have been found: geological, chemical, and paleontological. 

In other words, the Earth created water and water created life on Earth. A perfect symbiosis.