Notice how every science fiction movie or television show starts with a shot of the location where the story is about to occur. Movies that take place in outer space always start with a shot of stars and a starship. Movies that take place on another world always start with a shot of that planet. This is to let you know where you are. Novels and stories start the same way. You have to give the reader a sense of where he is and what's happening as quickly as possible. You don't want to start the story by confusing the reader.
