Planet 9 sits at the edge of scientific imagination, promising either an epic expansion of the Solar System or a lesson in ...

Planet hunters have grown used to strange worlds, but a handful of discoveries now point to something even more radical: giant planets that loop around their stars on orbits so skewed they almost defy ...

Studying the orbits of thousands of exoplanets shows that large planets tend to have elliptical orbits, while smaller planets tend to have more circular orbits. This split coincides with several other ...