A possible explanation...

Interesting... Maybe weyland is an engineer.

Considering he doesn't know anything about them, has never seen one, can't speak the language etc etc, i'd doubt it very much.

Hmmm...the best "civil war" theory I've heard about the Engineers. Keep up the good work.

Thanks Mr.Yutani

Nice idea, Ridley Scott many years ago posited the notion that a)the Space Jockey race were using the Alien as a bio weapon. or b) worse as a form of Terraforming. Just drop the eggs onto a world let them be colonised by the Alien(s) to wipe out the indigenous population then they come in and wipe out the Alien(s). Which one is the scarier concept? I know what my money would be on...

Interesting theory! there is also another very interesting theory posted by someone else here, it's called 'The Third Race Concept' you can find it fast, it was made recently.

Maybe its all an act. Maybe he's just acting like he knows nothing about them so they will all go and be his pawns.

@b5historyman - I remember reading that too... I still don't understand why an Engineer would 'create' us and then send black goo/Aliens to kills us. That's where my civil war idea came from. If they make a sequel hopefully some of the questions we all have will be addressed.

I think the black goo is a life-creating dark matter that the Engineers have discovered or created. It is a powerful DNA accelerant, altering chemical of some sort. They use to create life on worlds that could harbor life. But they know one must sacrifice himself to create life (the opening suicide sequence). It is also dangerous- if any of them is infected by the goo and their seed is spread thru sex, they could give birth to the facehuggers which will in turn give rise to the proto-xeno. Perhaps the mural serves as a warning or reminder that their homeworld was once destroyed by these killing machines (and practice safe sex!). They had to destroy Earth because the humans will be advanced enough to meet them or travel anywhere else in the universe and discover the black goo for themselves, or gets infected by it. They had previously thought it would be nice to leave them a message in prehistoric Earth, as a symbol or proof of their maker. But after a possible black goo outbreak in the temple, only one Engineer remained in stasis. Awakened by the synthetic human, he discovered that the android stole one of the ampules, in hope to becoming gods or immortal themselves. That's where he decided to give the ungrateful humans a hiding before deciding to fly to Earth to finish the job they were first tasked to do.

And if I can add, Prometheus is set out to take whatever secrets the 'gods' may have. Weyland is explicit in this. Hence the name of the ship. He wants immortality. He is afraid of dying. David has been programmed to do whatever it takes to steal it and make it work, even to the extent of infecting Holloway with the purpose of creating another life-form (makes him feel he is now a creator just like man who created droids). Just my take on the story, sorry if I inconvenience anyone.

Wow, this is a good theory explanation, well I guess it's kinda of make sense...

@Danial92 - Thanks :-)