This is a REALLY funny film it's based off a book but I haven't read it. The film is about a man called Arthur Dent and his home planet Earth being destroyed but he's saved by his friend Ford who is an alien from a planet in the vicinity of Betelgeuse working on the Hitchhiker's Guide. Here is the first part of the film.
There are 2 things you learn from this film and they are
1. Don't panic
2. Remember where your towel is