The authors add that in theory, you could have a huge rocky planet with no natural atmosphere, but that is challenged by current planetary formation models. Generally it is believed that planets assembled with bits of rock and gas attracting each other over time.
"One could in principle propose a rocky planet as big and massive as one would wish, with no atmosphere at all, but no natural process produces it. The accretion process and the competition for materials during planetary formation impose severe constraints on feasible planets," the authors wrote.
ANALYSIS: The Animals Behind the Sounds of Star Wars
But the authors note that several super-Earths that are both rocky, and that have surface gravities similar to our own planet, have already been spotted by telescopes. So perhaps the "Star Wars" strolls are not too far-fetched, they said.
"If while viewing ‘The Force Awakens" the reader sees Harrison Ford walking on Takodana as if he were strolling down Hollywood Boulevard, do not be too critical," they said at the end of the paper. "After all, this may not be so wrong."