Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

PHOENIX, Arizona (Reuters) -- A University of Arizona astronomer has found an object in the outer reaches of the solar system that could be the second brightest and largest so-called "minor planet ...

An international team including astronomers from the Center for Astrophysics | Harvard & Smithsonian (CfA) has announced the ...