The asteroid orbits the Sun in 368 days - a period similar to Earth's year - but it does not orbit in the same plane as the Earth.

BBC: Asteroid 2012 DA14 in record-breaking Earth pass

If your secret space plane's in orbit and doing its secret thing well enough, why bother bringing it home?

ENGADGET: Air Force X-37B space plane books additional time on orbital cruise, orders another margarita

So far, the research team has identified three planets circling Kepler-30, all of which orbit the star in the same plane.

FORBES: Astronomers Discover A Solar System Similar To Our Own