Planets in multiple-star systems may be habitable

In a finding that’s great news for fans of Luke Skywalker’s fictional home planet Tatooine, scientists say planets in multiple-star systems may be habitable – though in keeping with Tatooine’s hardscrabble image, it may be an uphill battle. Astronomers have long known that multiple-star systems are common. “Most stars are members of binaries [other than the coolest dwarf stars],” Manfred Cuntz, an astrophysicist at the University of Texas at Arlington. And, as astronomers are learning, many of these binary-star systems have planets – some circling a single star, and some circling both at once. Life on these planets could have a hard go of it, however. In binary star systems, this effect can be radically stronger, says Billy Quarles, a research scientist in the School of Physics at the Georgia Institute of Technology, especially if the planet’s orbit doesn’t lie in the same plane as its stars’ orbits around each other. “Seasons around these binaries may be a lot more variable than on Earth,” he says. “There are times when there are no seasons, and others when seasons [are larger], on a time scale of a few tens of thousands of years.”