What was Alien about?

Humans interacting with an unknown form of life in a hostile environment.
The creature is a human predator, a parasite and a monster so we get a movie about the creature's cycle of life, humans trying to survive and kill it.
And ultimately it's about humans crossing the line because the need for knowledge.

What is Prometheus about?

All of the above plus:
The power to give life and the power to end it.
A sacrifice to give life, birth, life, life against life, reproduction, parasitic and predatory relationships, death.
The relationship with our parents and creators.
The search for origins, eternal life, meaning and purpose.
Faith, belief and disbelief.
Sex, male and female.

Main Characters

- Elizabeth Shaw: a christian woman whose mother probably died when she was born*, incapable of bearing children, very masculine in the way she behaves because she didn't have a feminine model in her life, looking for her origins.

- Peter Weyland: an overambitious business man, looking for eternal life, close to his death.

- Meredith Vickers: Weiland's daughter, a woman who would like to be a man and so behaves like a man, in order to be liked by her father, because he wanted a son, not a daughter.

- David: Weiland's “son”, an intelligent robot, suposedly unable to feel emotions, just following orders, but appears to be quite curious himself.

What is life really about?
What is life?
Is life sacred or is it something evil?
What is love? Baby don't hurt me, no more.

And the meta meaning of the movie is: film as an evolved form of cave paintings.

Think about it.