[Outbackmanyep]

Originally Posted by [1ponders]

Part of the reason is to try to determine where all Earths water came from. One theory is that it is predominately Cometary in origin. Unfortunately the D:H ration of water on Earth is different to the D:H ratio of currently observed Comets.

However latest reseach seems to indicate that in the early solar system there were cometary type bodies in the inner solar system that had a different D:H ratio to the outer system Kuiper belt/Oorte cloud bodies. These inner "comets" may have been the source of earthly water.

Another reason is that the D:H ratio also gives an indication of the conditions in the developing solar nebula. Because Deuterium is more massive than H it would be more likely to be found closer in to the center of the developing solar system. Therefore it's distribution helps to explain mass, temperature and density conditions in the developing solar nebula

Thankyou Paul for that insight!
So thats another reason to research comets, if we find a comet that has a D:H ratio similar to that of earth then its possible that those comets could have been a source of terrestrial water!
Quite interesting....

Has there been other molecular interstellar clouds that have a D:H ratio similar to Earth or our solar system??