Astronomers have long speculated about the existence of a mysterious planet lurking far beyond Neptune, a world several times ...

"The formation of planetary systems is not exclusive to stars but might also work around lonely starless worlds." ...

NASA's Voyager probes have reached a mysterious boundary at the edge of the solar system, uncovering a searing "wall" hotter ...

Its inclined orbit challenges current models of the outer Solar System. Discovered by an international team, this object ...