Luke Skywalker bemoaned his lack of travel before the events of A New Hope. But researchers analyzing data from the Kepler space telescope say his home planet Tatooine would have been on an epic journey of its own before Skywalker’s birth.
That’s because Tatooine is a circumbinary planet, meaning it orbits a double-star system. Such planets do exist in the non-fictional universe, one of which is Kepler-34(AB)b, named after the space telescope used to study it.
Having two stars close to one another is about the worst possible situation for forming a new planet because having the two different gravitational pulls greatly increases the chances of rocks colliding and damaging one another rather than combining.
A team led by Dr Zoe Leinhardt and Stefan Lines of the School of Physics at Bristol University have used data gathered from the Kepler project to simulate planet formation around binary stars. The simulation used around one million “planetary building blocks” to see how they would be affected by the gravity.
The simulation found that not only was it difficult for planets to begin forming in such a situation, but even if they did, they’d continue to struggle to grow. The researchers concluded that it was “unlikely” Kepler-34(AB)b was formed in its current location and that it was “more plausible” it was formed at least 1.5 Astronomical Units (139.5 million miles) away.
They also suggested it was likely that nearly all other circumbinary planets made similarly “significant” journeys after formation. The only possible exception is Kepler-47(AB)c which is far enough away from its dual suns that it may have formed in its current location.
The full research is published in Astrophysical Journal Letters.
(Image credit: Artist impression of Kepler-34(AB)b, David A. Aguilar, Harvard-Smithsonian Centre for Astrophysics)