[Suzerain of Sheol]

Technically speaking, if my understanding of science isn't failing me (it might be), every molecule in existence is equally primordially ancient, originating from the singularity that spawned the Big Bang, so our water is a lot older than that. :P

Do correct me if I'm wrong, though.

This discovery seems really interesting from the perspective of the theoretical interplanetary dissemination of life-producing matter, like you mentioned, Pathosis. Figuring out whether we arose on Earth naturally or there was some kind of astronomical interaction (I'm talking meteors and such, no aliens :P) that produced the right mix of chemicals and environment for life, would tell us a lot about the prospects of encountering other life forms out there.

Or not. I'm a writer, not a scientist. :P