Space Jockey Scene in 'Alien'.

Well done @CanadaPhil, I am TOTALLY onboard with that. Maybe the multiple "strains" have to be separated, different ships/temples, as in different labs working with different species and specimens collected from around the universe--and need to be kept separated and not cross-contaminated. Quite possibly, the alien ship we see that takes off and gets crashed by the Prometheus, in fact crashes, and another ship that is further along in the development of the xeno (carries the eggs), takes off headed for earth and a mutated David is onboard that ship and veers it to a barren Planetoid (lv-426) to foil the trip to earth. THE POSSIBILITIES ARE ENDLESS!!

Actually that makes a lot of sense that that SJ was leaving for earth with the Xeno eggs if we follow the bio-weapon theory. He was going to release them against the humans. Whatever crashed him will hopefully be described in Prometheus somehow. I really can't see that not being worked in, I mean he had that scene for a reason..and we'll hopefully learn why it was there.