Pluto's days, though they drag on a bit at around 153 hours, are nothing compared to its years. Pluto's orbit takes 248 Earth ...

Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

Astronomers studying the distant reaches of our Solar System have identified an unusual trans-Neptunian object (TNO) locked in a rare orbital configuration with Neptune. The object, discovered through ...

Thanks to the discovery of thousands of exoplanets to date, we know that planets bigger than Earth but smaller than Neptune ...

There may be more ringed objects in the outer solar system than anyone knew. This week, researchers revealed that the egg-shaped dwarf planet Haumea — one of four known diminutive planets that circle ...