Earth-like planets with two suns, resembling Tatooine in Star Wars, may be widespread, scientists believe.

In the movie, Luke Skywalker's home world had twin sunsets because it orbited a pair of stars.

So far, scientists have only identified uninhabitable gas-giant planets in orbit around binary stars.

But new computer simulations show that solid, Earth-like planets such as Tatooine are not only theoretically possible but may exist in large numbers.

US astrophysicists Ben Bromley and Scott Kenyon conclude in their study: "Tatooine sunsets may be common after all.

"Our main result is that outside a small region near a binary star, (either rocky or gas-giant) planet formation can proceed in much the same was as around a single star. In our scenario, planets are as prevalent around binaries as around single stars."

The research shows how binary stars - pairs of stars bound together by gravitational force - can be orbited by asteroid-sized rocks that clump together to form planets.

Dr Bromley, from the University of Utah, said: "It is just as easy to make an Earth-like planet around a binary star as it is around a single star like our sun. So we think that Tatooines may be common in the universe.

"An Earth-like Tatooine would have no problem forming right where it needs to be to host life."

Previously many experts doubted that Earth-like rocky planets could form around binary stars.

The problem was that asteroids, or planetesimals, need to merge gently in order to grow. Those orbiting pairs of stars were thought to follow tangled paths that caused them to smash together destructively.

But the new study shows that the asteroids are likely to settle into oval, not circular, orbits which helps prevent such fatal collisions.

The American space agency Nasa's Kepler space telescope has discovered more than 1,000 planets outside our solar system, including rocky worlds in the "habitable zone" not too close or far away from their host stars.

Within the habitable zone, temperatures are mild enough to permit liquid surface water and, possibly, Earth-like life.

Seven planets have been found orbiting within or near the habitable zone around binary stars, but all are gas giants similar to Jupiter.

However this may only be because small, rocky planets are so much harder to spot that giant gaseous ones, according to Dr Bromley.

The study appears on the scientific pre-print website ArXiv and has been submitted to the Astrophysical Journal for review.