BLOG: Water did not originate on Earth?

Against the conventional wisdom it is now discovered that water did not actually originate on planet Earth but was brought down to it by meteorites.

This discovery startled the scientific world as it was not expecting that to ultimately turn out as it appeared highly unlikely keeping in view the very nature of liquidity itself. It is a stunning discovery belying almost all factors concerned with water, the vital prerequisite for life on Earth and the qualities it possesses.

Its presence on earth was a given as it was considered one of the aftereffects of the Ice Age. It was considered an essential ingredient of the growth of life on Earth without which life may not have originated.

The new study reveals that water was actually brought to the Earth two million years after its formation by angrites in the early years of the formation of the Solar System.

Angrites are known to be a rare group of water-rich basaltic meteorites found in outer regions of the universe.  A fresh look at the rare basaltic angrites suggests that volatiles, which are elements with relatively low boiling points such as water, could have been brought to our planet by meteorites during the first two million years of the Solar System.

Journal Geochimica and Cosmochimica Acta published by Elsevier that specialises in wide range of subjects in terrestrial geochemistry, meteoritics, and planetary geochemistry contained an article in its recent publication on the subject that was also quoted by Phys.org (PO) by MIT researchers that specifies that composition of water on Earth and the composition of water in the angrites “match perfectly”.

The study indicates that water on the asteroid and the water on Earth came from the same source. The research implies that water arrived on Earth even before it was fully formed when it was likely to have been only 20% of its current size.

The lead author of the study, Adam Sarafian, belonging to department of Earth, Atmospheric, and Planetary science at MIT, says: “It’s a fairly simple assumption to say that Earth’s water at least started accreting to Earth extremely early, before the planet was even fully
formed. This means that when the planet cooled enough so that liquid water could
be stable at the surface, there was already water here.”

The scientific research on the Earth describes that it was fully formed about 4.5 billion years ago and by this time Mars already had a 20-million-year head start, with a stable mass, and water and other chemicals on its surface, like carbon, fluorine and chlorine.

On the other hand, Earth, as an inner planet had to go through a long phase of being hot and dry before it was fully formed with a stabilised mass.

The scientists believe that at this stage of planetary evolution, Earth was nothing more than a proto-planet with a molten surface of magma. They are of the opinion that faced with extremely high temperatures, water was not able to sustain itself as even carbon with a melting point of 4,800 degrees Celsius was considered to be volatile and unable for sustenance.

The researchers carried out measurement of olivine, a common mineral in basaltic meteorites, for volatile elements hydrogen, carbon, fluorine and chlorine to find out their “melt composition” because basalt is formed when molten igneous rocks cool. The researchers opined that once they found out the melt composition only then they were able to calculate the content of the water content other planetary body.

Resultantly it was discovered that parent angrite asteroids likely had about 20% of Earth’s current water levels.

While this amount is not considered decisive at the moment but 4.5 billion years ago, when the Solar System was still hot, it actually constituted quite an abundant amount of water.

The researching team was also involved in estimating how big this angrite parent body could have been by means of using water and carbon levels found in them.

The researchers considered this approach appropriate because both water and carbon content are dependent on pressure, so by estimating pressure, the team was able to calculate size of the angrites. Their calculation is that the angrite asteroid that came filled with water to Earth was about the size of asteroid Vesta which is roughly 525 kilometers in diameter.

It may be noted that Earth is about 25 times larger in diameter than Vesta.

This important discovery has opened up the possibility of further finding out the nature of angrites and efforts then may be afoot to create them and transport them to other planets for procuring water.

The research is on and might bring in something more surprising and open up more doors for the scientific community.