A recently discovered celestial body is rewriting our knowledge of the Kuiper Belt and maybe challenging the existence of the ...

Almost 20 years after Pluto was infamously downgraded from its status as a planet, scientists now believe they have ...

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

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 ...

Many planet classification schemes have been proposed ... These bodies were approximately the size of Pluto, which was then considered a planet. With a new definition, the small worlds and Pluto ...

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

Why Pluto Doesn't Fit "Pluto is a dwarf planet. So be it — it's a classification," says Thierry Montmerle, the group's general secretary. "It's not a demotion or a promotion." He says Pluto ...

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 ...

"It just makes no sense from a classification standpoint to ... The only reason Pluto was ever deemed a planet, Brown added, is because it was first detected so long ago, before people realized ...

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

When this happened, Alan Stern, the principal investigator behind the New Horizons Pluto fly-by mission, was not very amused. Our current classification system of what makes a planet a planet just ...