It should be studied in film class as a prime example of how to integrate design and story. Its emotional impact and meaning (substance) is so integrated with its unique aesthetic configuration (style) that one cannot really separate the two when analyzing it. The "science" aspect may or may not be bollocks, but it is presented in such a textured, believable way that is uncanny.
God, Ridley Scott used to be cool. The front-runner, in my mind, for both best horror AND best sci-fi film ever. Has its flaws and clichés, but they're totally overcome by the flawless direction, design, and ensemble acting. The alien might be the best monster ever designed for a film, and the use of color, light, and space contribute perhaps more than anything else to just how damn scary Alien actually is.
Ridlley Scott is a world-class master in the science of art and editing. Here he creates an atmosphere by fear and pace of an unseen and unknown evil. He sends us to a forbidden place for humans alone and adapts the most unpleasent creature for the crew which at some time knows it's expendable and the most important thing is bringing back alien life-form. But, it's not overall greatness.