NASA’s most recent photos of Pluto, captured by the New Horizons spacecraft, have revealed some of the most intriguing and ...

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

The newly discovered object, named 2017 OF201, has a 25,000-year orbit and is believed to be a large contender for dwarf ...

an underdog among its much larger planetary siblings of the inner planets and the gas giants beyond the asteroid belt." ...

A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

Pluto should be reclassified as a planet ... Instead, Metzger recommends a planet classification based on whether it is sufficiently large so that its gravity allows it to become spherical ...

Both Morison and Byrne agree the IAU classification has had a scientific impact, and think Pluto and similar bodies should be classified as planets. But “it’s not particularly crucial ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

There were a number of campaigns launched that were aimed at ensuring that Pluto was reinstated as a planet ... and head of the IAU's Planetary Classification and Experimental Nomenclature ...

Alison Klesman, senior editor, Astronomy: To me, Pluto is not a planet — and that’s a sign of progress. Classification and nomenclature in science is admittedly often arbitrary, but the idea ...