The Martian is the rare movie that’s better than the book. In this case, it’s mostly because the book is so mediocre and the film makers (it was directed by Ridley Scott) manage to solve the problems its writer, Andy Weir, could not. The story is a simple one: Astronaut Mark Watney (played by Matt Damon) is left for dead on Mars, and he needs to stay alive for more than a year until he can be rescued. The book does a great job of explaining how this could happen, and patiently walks us through Watney’s forays into Martian agriculture and transportation. Told mostly through his journal updates, Watney narrates his ordeal with humor and a breezy, can-do attitude. But the book lacks any attempt to convey the inner life of a man stuck millions of miles from home. He never despairs, he never pines for missing friends or lovers (and apparently doesn’t have any), he’s never angry at the hand fate dealt him, and so never becomes more than a glib sketch of a person. And this is where the movie succeeds. In only a few brief scenes, perhaps less than a minute of total screen time, Damon flashes the emotions of a man who has every reason to rage against his predicament, and becomes someone we can understand. The movie also smartly introduces the rest of the cast – Watney’s fellow astronauts and the NASA ground crew – much earlier than the book, which abruptly lurched from a Robinson Crusoe-like narrative to a rescue mission with lots of characters. As a result, some scenes of Watney’s travails are cut and new ones, featuring Jessica Chastain as the spaceship’s commander, are added. Those alterations are mostly positive (save for an unnecessary coda set back on earth) and help the movie build momentum on Earth, in space and on Mars towards a satisfying and moving climax. Much like Apollo 13, the movie celebrates the resourcefulness of NASA’s engineers and feels overly promotional (I’m sure the real-life NASA administrators loved it). Given the billions of dollars spent to save one astronaut, I would have liked to hear from an ethicist arguing whether the money could be better spent on a malaria vaccine, say, that could save millions of lives. But The Martian isn’t that kind of film. It’s a rousing adventure that reminds us how, in capable hands, effective a story-telling medium movies can be.