Cosmology is facing a new theory that could revolutionize what we know so far about the origin of one of our most precious goods: water. The Astrophysical Journal Letters publishes this study, led by Lise Boitard-Crépeau, which suggests that the origin of water could lie on Earth. So far, the most studied idea is that water formed in the snow line, a region of the protoplanetary disk, from which water would adhere to dust particles. The Boitard-Crèpeau team used models of the protoplanetary disk, considering various temperatures at 1 cosmic unit.
This model has also made it possible to calculate the amount of water in various types of meteorites, such as chondrites. These are rocks that have not changed since the origin of the Solar System, so their results have reinforced the idea that water has not been “imported”. It has also been possible to calculate the amount of deuterium (the heaviest water). The results have indicated that the presence on Earth is the same as that found in meteorites or asteroids.
This is not the first time that the origin of water has been proposed as being on Earth, but it is the first time that evidence has been presented with quantum chemistry. Although it has not yet been confirmed, the theory that water was brought by a comet or an asteroid is increasingly being questioned.
“Late veneer” hypothesis
The Astrophysical Journal Letters, reports the study of the researcher Lise Boitard-Crépeau, who puts on the table the hypothesis of “late selling”. The most widespread belief in the scientific world is that water was “imported” to Earth. It is supposed to have been created in the snow line, in the protoplanetary disk, where it adhered to the dust motes in suspension in the form of vapor. According to this theory, the Earth had such high temperatures that it was not able to hold those water particles, so it had to be brought by something or someone.
However, this theory is not proven, so more than one scientist has suggested that the origin of water is in the Earth itself. To flesh out this hypothesis, Boitard and his team resorted to quantum chemistry, through which they were able to reach the following conclusion: terrestrial water could have been inherited mostly from dust grains that were in the Earth’s orbit, without the need for migration from outer regions”.
Evidences
Through these calculations, they were also able to determine the amount of water carried by some meteorites, such as chondrites. How important is this? Very important, because these are rocks that have remained the same since their origin at the beginning of the Solar System. That is why the presence of water reinforces the theory even more. The origin of water has its main debate in the difference between the ratio of normal hydrogen and the heavier hydrogen, deuterium. The ratio between the two, known as the D/H ratio, is the determining chemical fingerprint for comparing water on Earth and in comets and meteorites.
Conclusions
The results obtained with the calculations of this new model, not only suppose that it is a possible hypothesis, but almost viable. It is not a surprise for anyone to see this hypothesis, but it is the first time that it has been backed up with evidence as solid as the model and the results obtained.
However, the researchers are not in a hurry, and are aware that it is still too early to consider this theory as 100% valid. More observations and adjustments are needed, but what they have been able to affirm is that “these results suggest that a significant part of the Earth’s water could have had a local origin, without the need for delivery from beyond the classic snow line”.
This new observatory will be able to answer all the questions we have about space!
