For the first time since Pluto was demoted, the idea of a true ninth planet is edging from speculation toward something testable. Instead of restoring Pluto, researchers are closing in on a different, ...

Just when you thought you knew all the worlds in the solar system, astronomers go and discover a new object that could rewrite the space map. This icy world, temporarily named 2017 OF201, could be a ...

Space probe isn't done after historic Pluto flyby. — -- New Horizons conserved energy by taking naps on its 3 billion mile journey to Pluto but the spacecraft isn't done yet and may have enough ...

Preface: Inside the farthest exploration in history -- Introduction: Out of lock -- Dreams of a grand tour -- The Pluto underground -- Ten years in the wilderness -- The undead -- New Horizons at last ...