New clues in search for Planet Nine
New location, brightness projections raise hopes of actually spotting distant world
More clues about where to search for a possible ninth planet lurking in the fringes of our solar system are emerging from the Kuiper belt, the icy debris field beyond Neptune. And new calculations suggest that the putative planet might be brighter — and a bit easier to find — than once thought.
Evidence for the existence of Planet Nine is scant, based on apparent alignments among the orbits of the six most distant denizens of the Kuiper belt (SN: 2/20/16, p. 6). Their oval orbits all point in roughly the same direction and lie in about the same plane, suggesting that a hidden planet, about five to 20 times as massive as Earth, has herded them onto similar trajectories.