This is exactly what Ridley said: "It’s, you know, whenever you’re talking about science-fiction, it always sounds pretentious or corny...but it’s actually “The beginning of time”. But I think we’ve got it right. (He laughs) So, it will be a pretty good beginning of time.
I think it's worth repeating all the stuff Ridley has said about the prequel up to this point.
Scott said that "the film will be really tough, really nasty. It's the dark side of the moon. We are talking about gods and engineers. Engineers of space. And were the aliens designed as a form of biological warfare? Or biology that would go in and clean up a planet?"
Scott said "I always figured it’s a weapon, and I always figured that [the ship in the first Alien] was a carrier of weapons. Therefore, who is that, inside that suit? That wasn’t a skeleton, that was a suit. And if you open up the suit, what do you get inside it? And why were they going, where were they going?"
The film will explore the nature, origin, and "staggering civilization"of the alien race of the space jockey, as well as the beings' fictional anthropogenic role in the origins of humanity on Earth. Scott told the Hollywood Reporter, "NASA and the Vatican agree that it is almost mathematically impossible that we can be where we are today without there being a little help along the way... That’s what we’re looking at...at some of Erich von Däniken’s ideas of how did we humans come about."
"The cast find an establishment which is not what they expected it to be, it’s a civilization but what we find in it is very uncivilized behaviour."
The prequel went through several drafts, featured a female lead character and would also focus on terraforming and the fictitious Weyland Industries before its merger with the Yutani Corporation.
Scott said that the script dealt with the need for "dematerializing and rematerializing" in order to achieve what one report described as "Near Faster-Than-Light travel", and he was also quoted as saying "I think the closer it is to the truth, the closer it is to the technological feasibility then it becomes that much more interesting (I assume this is what we are seeing when one of the crew appears to be dematerializing in one the the trailer cuts)
Scott stated that the original Zeta II Reticuli planetary system WOULD be part of the prequel story.
Scott said at WonderCon that some of the questions presented in the film are left unanswered and could be answered in a sequel. "If we're lucky, there'll be a second part. It does leave you with some nice open questions."
When asked if we would see the original xenomorph in Prometheus, Scott said "No. Absolutely not. They squeezed it dry."
When asked if a sequel would move closer to being a prequel to the events of Alien, Damon Lindelof said "if we’re fortunate enough to do a sequel to Prometheus, it will tangentialize even further away from the original Alien."