The twin suns of the planet Tatooine in Star Wars.
In a stunning new theory, U.S. astrophysicists say Earth-like exoplanets orbiting binary stars could be as numerous as rocky planets orbiting single-stars.
This radical finding contradicts conventional scientific wisdom that says binary stars will likely prevent the formation of planets by dispersing the gas and dust needed in the planetary formation of Earth-like rocky planets.
What they're saying, in effect, is the Star Wars planet of Tatooine, Luke Skywalker's desert home world orbiting two suns, isn't only possible, it's commonplace.
Forming rocky planets in a binary system not only is possible, it's "not even that hard," said Scott Kenyon, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, Dr. Kenyon and University of Utah astrophysicist Benjamin Bromley performed the calculations leading to their joint modeling study.
They found gas giants as large as Jupiter orbiting binary suns are likely to be as common in binary systems as they are in systems with a single sun.
"If that's true, then Earth-like planets around binaries are just as common as Earth-like planets around single stars," said Dr. Kenyon.
"If they're not common, that tells you something about how they form or how they interact with the star over billions of years."
Both astrophysicists recognized that binary stars hosting planets are essentially scaled-up versions of the Pluto-Charon system they were earlier studying. They applied their calculations to a hypothetical binary star system with a circumstellar disk of dust and debris.
"The modest jostling in these orbits is the same modest jostling you'd get around a single star," said Dr. Kenyon. This jostling allowed rocky inner planets to form.
They believe planets found around binary stars would have formed farther out and migrated in over time since there's too little material within the inner reaches of a circumstellar disk to build giant planets, said the Christian Science Monitor.
Their calculations imply that as more planets are discovered orbiting binary stars, a rising number of Tatooines will be among them.
Tatooine "was science fiction," said Dr. Kenyon. But "it's not so far from science reality.
