Wednesday, December 10, 2014

Comets Not the Source of Earth's Water!

Comets did not bring water to Earth.  This startling piece of news comes from scientists studying data coming back from the ESU's Rosetta.  The data, they feel, points towards asteroids as the watery culprits.  Still, other scientists want more data before ruling out comets completely.

Though the lander Philae's batteries have long since been depleted after it landed on comet  67P/Churyumov-Gerasimenko, November 12 2014, the "mother ship" Rosetta has continued to study the comet up close.


This historically close look at a comet may well answer the questions of whether it was possible that these primitive bodies brought water to Earth billions of years ago. Data  gathered by Rosetta's two mass spectrometers suggests this may not be the case.

The authors conclude it is more likely that the water came from asteroids, but other scientists say more data is needed before comets can be ruled out.

Since August, the Rosetta probe has been orbiting Comet 67P and on  November 12 Philae, touched down on the comet's surface.

This historically close look at a comet may well answer the questions of whether it was possible that these primitive bodies brought water to Earth billions of years ago.  Data gathered by Rosetta's two mass spectrometers suggests this may not be the case.







Earth's water is very distinctive. The majority on Earth is made up of two hydrogen and one oxygen atoms.  Infrequently one of the hydrogen atoms will be replaced with a deuterium atom - better known as "heavy water". Deutertium however is exceedingly rare.  For every 10,000 water molecules, three deuterium atoms can be found, a very distinctive ratio of light to heavy water, not easily changed and persists for a very long time.

When the team compared the water on Earth to that of Comet 67p, it was discovered that there was far more heavy water on Comet 67P than on Earth, more than three time that found on Earth.

 Complete BBC News online article HERE

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