Where on Earth did our water come from. Well, obviously not from Earth, of course, but from space. But did it come from comets, or did the water form naturally right here in the Solar System, and the Earth just scooped it up?
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Hi Frazer & Pamela
Although astronomers belive that the Earth’s water came from outer space geologists belive that at least 50% came from within the planet itself.
Of course taking this into account will inform the current debate revolving around the D/H ratio to be found in various comets eg 67P.
Will put a more complete bit together by email.
Brian – Roseland Observatory
Hi Frazer and Pamella
Congratulations on an excellent episode, it was really informative and thought provoking. I was wondering whether there had been an isotopic analysis of the oxygen in the water of comets or asteroids and whether the ratio of stables for that element would be another possible indicator of the origin of Earths’ water? Also, I did some googlework and found that by mass, the percentage of water on Earth is about .02%, is there any way of determining this basic ratio for comets or asteroids?