When did the Derelict crash?
If the Engineers created the Xenos when did they?
A lot of people think that the last Prometheus will end with the Derelict ship crashing on LV-426. But why would they end two Prometheus films with a Derelict ship crash? Also, according to Lendelof (the writer) hopes Prometheus will go it's own course, and Scott seems pretty serious about not doing Alien again.
But then I heard about these documents on the Prometheus blu-ray. These indicate that Weyland knew about a transmission from LV-426, probably the Warning. Which could mean the Derelict was on LV-426 way prior to Prometheus. Probably someone who escaped LV-223.
But, can these documents be considered canon? If not, why would they put them there? I feel like, this is Scott's way of saying, "We are not gonna lead into Alien, we want this series to go it's own course."
In fact, I think the perfect beginning of Prometheus 2 should be this:
We see the outbreak on LV-223, where during the outbreak, THE Space Jockey gets attacked by a Facehugger. After all the Engineers, except the Jockey and the Engineer of Prometheus in stasis, the Jockey takes control of his ship to either use the eggs to destroy the human race. On the way, the Alien births from him and he crashes on LV-426 where the warning signal goes off. We see the titles. Then we cut to Shaw and David after Prometheus and the story continues from there.
That way, it would tie up loose ends and Prometheus can go it's own course without being bound to end with the Derelict crash. That's my theory.