[numberonepal]

I do think that it coming here from another of our planets could probably be ruled out, though.

What about the possibility of life being seeded on Earth from a celestial collision?

[ZX12R]

What about the possibility of life being seeded on Earth from a celestial collision?

If I understand your question, I think it would have had to be a collision with something (rogue/life bearing) encountering our solar system.

[KamperKen]

"What about the possibility of life being seeded on Earth from a celestial collision"

That was largely Watson and Crick's as well as Hoyle's opinion, that life originated "elsewhere".