Fans of the genre will tell you that the best science fiction is never about spaceships or robots or impossible inventions, but about human concerns brought into focus by fantastical plot contrivances. In the case of this independent film, the human story is never in doubt, only what the sci-fi aspect has to do with any of it.

As the film opens, the future is looking bright for both Rhoda (Brit Marling), a 17-year-old headed to MIT on a scholarship, and John (William Mapother), a respected composer with a growing family. They don’t know each other, but the instant of their meeting takes away everything they cherish. Four years later Rhoda, who was at fault (without John knowing it), sees a chance to assuage her guilt by making herself a part of his shattered life.

Yes, but where’s the sci-fi aspect? On the day of their meeting, scientists discover that our planet has a doppleganger, a twin planet that until now has been hidden from us because it is 180 degrees away in our orbit, always on the other side of the sun. Initial contact reveals that it is an exact copy, populated by the same people with the same lives and same memories as us. Or at least until we discovered each other and began to diverge.

In other words, a mechanism for wish fulfillment for two characters who regret was has become of their lives. This lends a metaphysically murky aspect to what is otherwise a story of rebirth that is not the less affecting for its improbability. (If my description of the plot also seems murky, I’m trying not to give any of it away.) If it’s not completely satisfying, Another Earth is undeniably a strong calling card for Marling, who not only stars in it but wrote and produced it in conjunction with partner and director Mike Cahill.

—m. faust

Watch the trailer for Another Earth