Rosetta finds comet's water vapour to be significantly different from Earth's
(For future readers, see dang's comment on how he changed the title from "Rosetta first results: ocean water not from comets")[1])I don't know why you changed the title to something claiming a stronger result than their title: "ROSETTA FUELS DEBATE ON ORIGIN OF EARTH’S OCEANS". I'm not a planetary guy, but I think while the evidence is moving that way, the claim in your title is definitely premature.Here's a distillation of their results (from their post) that seems far more in line with their claims than your title:>“Our finding also rules out the idea that Jupiter-family comets contain solely Earth ocean-like water, and adds weight to models that place more emphasis on asteroids as the main delivery mechanism for Earth’s oceans.”[1] https://news.ycombinator.com/item?id=8731304