Outer orb sits in habitable zone of binary star system
BEIJING — And then there were two. The Kepler spacecraft has spied the first pair of planets passing in front of the binary star system they orbit. Adding spice is that the outer planet — a potential Neptune-like world — inhabits the life-friendly zone around the two stars.
“It receives about 88 percent the amount of energy the Earth receives from the sun,” said William Welsh of San Diego State University on August 29 at the International Astronomical Union meeting. “And it’s a multiple planet system. It’s hard enough to imagine how you get one planet in the binary; now we have two.”