Planet Nine's days of lurking unseen in the dark depths of the outer solar system may be numbered. The hypothetical giant planet, which is thought to be about 10 times more massive than Earth, will be discovered within 16 months or so, astronomer Mike Brown predicted. "I'm pretty sure, I think, that by the end of next winter — not this winter, next winter — I think that there'll be enough people looking for it that ... somebody's actually going to track this down," Brown said during a news conference Wednesday (Oct. 19) at a joint meeting of the American Astronomical Society's Division for Planetary Sciences (DPS) and the European Planetary Science Congress (EPSC) in Pasadena, California. Brown said that eight to 10 groups are currently looking for the planet. At the "next one of these [DPS-EPSC meetings], we'll be talking about finding Planet Nine instead of just looking for it," added Brown, who's based at the California Institute of Technology (Caltech) in Pasadena. That would be a