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, ...

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 ...

Scientists studying the interstellar object ‘Oumuamua have proposed that it may be a fragment from a Pluto-like planet beyond ...

Scientists have detected methane gas glowing faintly above Makemake, an icy dwarf planet smaller and farther than Pluto in space. Until now, Pluto was the only object that far out in the solar system ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. A composite image comparing the relative sizes of our solar system's known dwarf planets, ...

WASHINGTON, Sept 26 (Reuters) - Astronomers using the Hubble Space Telescope have observed a white dwarf - a highly compact stellar ember - that appears to have gobbled up an icy world akin to the ...

Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics but collectively believed to be ...

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 ...

Ammonite was discovered using the Subaru Telescope in Hawaii, with follow-up confirmation from the Canada-France-Hawaii Telescope. Its orbit and size officially qualify it as a distant dwarf planet.

Pluto sits far out in the Solar System, small and dim, moving at a pace that barely fits human timelines. It was found in ...