Where did the water on Earth?

Extensive before that scientists began to wonder about the origin of water on Earth . And so far the official maintained that the volatile elements (such as hydrogen, nitrogen or carbon), and even the first organic matter, arrived here from abroad , contributed by comets and meteorites by class of origin very old, the carbonaceous concretes . Both classes of objects are formed beyond the orbit of Jupiter and "migrated" then into the Solar System.

Now a new study has just revealed that it was not .Of course, determine exactly where they come from these essentials means being able to understand how water came, and life to Earth. Now a group of researchers from Carnegie Institute of Washington has just published an article in Science whereby the water on our planet is not the same that was distributed in the form of ice throughout the solar system at the time of its formation, but that came much later. And not far away aboard comets from the outer solar system, but much closer: the asteroid belt that is in between Mars and Jupiter.

To Cornel Alexander, principal investigator of the study, a large amount of ice water was distributed throughout the early solar system, but the ice was never part of the materials that were added to form the Earth. That ice early today may be found in objects such as comets or carbonaceous concretes cited above. But his analysis shows, the researchers said that the two types of objects were not born beyond the orbit of Jupiter, as previously believed, but in two remote areas. Comets formed in the outer Solar System. carbonaceous concretes did a lot closer .

Alexander was able to establish this difference by calculating the ratio of deuterium (an isotope of hydrogen) ice water content of 85 carbonaceous concretes. The farther from the Sun has formed an object containing more deuterium. And if comets and carbonaceous concretes formed in the same place, the ice should contain the same or similar, amount of deuterium. Not so.

The meteorites analyzed ice contains much less deuterium than the comets, suggesting that the latter formed much farther from the Sun This result also contradicts the accepted models of how the Solar System acquired its current architecture.

For Alexander, the deuterium content of carbonaceous concretes indicates that these meteorites must have formed much closer to the Sun those comets. Specifically, in the asteroid belt, the great ring of rocks that lie between the orbits of Mars and Jupiter. And hence, the study suggests, from which precisely the Earth's water. Alexander is convinced that the results of their research force to review the current theories and will help in passing, to solve a handful of issues that until now had resisted Science.