When Luke Skywalker stares off toward the horizon of Tatooine at a double sunset in “Star Wars Episode IV: A New Hope,” we know we’re watching a moment of pure science fiction.
At least, that was the assumption until now, as it appears that the science may have just caught up with the fiction.
So far, astronomers using Kepler Space Telescope data have only identified a handful of planets orbiting binary star systems, but none of them are the Earth-like, habitable — if extremely tumultuous — type of orb that spawned Luke and Anakin (although at least one such planet candidate was identified using other techniques). Rather, they tend to be larger gas giants like Neptune or Bespin. (Astronomers have yet to spot any Cloud Cities in the upper atmospheres of these planets.)
The assumption among scientists until now has been that the orbits of potential planetesimals around a two-star system would be more oblong and plagued by “ripples” in their paths rather than the smoother, neat concentric circles seen in solar systems like our own that allow planets to develop without risk of colliding with each other.