Originally posted by sonhouse
I posted this first in spiritual to talk about philosophical aspects but maybe it should be here in science.
I don't think the idea that "life" originated in space and effectively "seeded" our planet is new. Without checking I seem to remember Fred Hoyle was an advocate based on noticing complex particles in space. For our own case, it does not seem to be a necessary hypothesis in so far as we can account for life without it. But the idea survives for example in the suggestion that some viruses might be dumped onto us from space - I am not a fan of the idea because I see viruses as just another variant on the evolutionary theme, not some weird alien species. But I have not got the same qualification to comment as its advocates.
Of course just because it is not necesary does not mean it is not one possibility. Certainly at the level of non-biological elements, such as Carbon, then we know they were formed in earlier stars and without them life would be impossible.
It is worth remembering that when life originated here, conditions on Earth would have been intolerable for most current life forms - the early forms of life effectively created the atmosphere we now enjoy. So the existence of living organisms in other environments is not unlikely and if our search is for any life form, not just an evolved and intelligent life, then it allows a much wider range of options. Quote from your source: "When the team began looking for amino acids in carbon-rich meteorites, it was considered somewhat of a long shot, but now: "We would be surprised if we didn't discover amino acids in a carbon-rich meteorite," says Burton."
Once there is life however, in whatever form, then a process has to be allowed by which this can evolve into more complex structures and ultimately acquire intelligence. Our best account of this process would be natural selection and related evolutionary pressures. This must imply quite a complex environment which is certainly not available on a meteorite.