Directed by Mike Cahill. Starring Brit Marling, William Mapother, Matthew-lee Erlbach. 92 mins ***

The combination of micro budget indie production values and a science fiction premise can be an awkward one, primarily because it severely limits the options. As soon as you see its grainy, digital images you know that this film about the appearance of a mirror image Planet Earth has only a narrow range of story possibilities available to it, all of which are from the thoughtful and low key end of the market.

On the night the discovery of Earth II is announced, both Rhoda (Marling) a young science student and Burroughs (Mapother) a successful composer appear to have exciting futures ahead of them. Then one momentary lapse wrecks both their lives. Four years later both are just shells of people, while the sky is now filled by an identical planet Earth.

The premise is sci-fi but the film, written by director Cahill and lead actor Marling, is more human drama, a dramatic two hander between Rhoda and Burroughs, and one that embraces some fairly blunt dramatic devices. The contrived way they come together will test many a viewer’s patience, while Earth II is used purely as a device for potential redemption. In a sci-fi movie surely it would be a harbinger of a matter/anti-matter clash that would nullify the universe.

(The film’s science seems a bit shaky. When it is first discovered it is just a small speck in the sky. Four years later it is enormous, filling the sky like the moon that ET and Eliot cycled across. Logic suggests that it is heading towards us on a collision course but that possibility is never raised. It seems that the planet has approached at great speed from distant space before deciding to settle at a respectful distance from us.)

Another Earth offers viewers any number of opportunities to give up on it but I think it rewards any indulgence a viewer allows it. The two central performances carry it, particularly Mapother who has a softly spoken authority. The ending is a bit of a cop out, yet an effective one. It isn’t entirely satisfactory yet it stays with you and that goes for the film as a whole which has a very effective air of low key mournful unease.