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 unusual orbit of a possible dwarf planet, known as 2017 OF201, makes it less likely that our solar system contains a ...

[Our Solar System: A Photo Tour of the Planets] You may like Scientists found a possible new dwarf planet — it could spell bad news for Planet 9 fans Solar system guide: Discover the order of ...

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

OF201 spends only 1% of its orbital time close enough to us to be detectable. The presence of this single object suggests ...

But here’s a new exciting find from the far reaches of our solar system: Astronomers have discovered a dwarf planet that’s even farther away than Pluto – so far, in fact, that its orbit ...

Astronomers have found a dwarf planet out ... small objects far out in our solar system, and it adds to a tantalizing theory about another much more massive “Planet X” hiding beyond Neptune.

A newly found object may set a new record for the most distant dwarf planet in the solar system. The object, called V774104, lies about nine and a half billion miles from the sun, or two to three ...

There may be another world lurking between the orbital lines of our solar system. Astronomers in Japan have published their theory of an “Earth-like planet,” dubbed Planet Nine, that’s ...

For three-quarters of a century, schoolkids learned that our solar system has nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. But things changed five years ago.

Although hundreds, or perhaps thousands, more solar system bodies may eventually join the list, the IAU officially recognizes just five dwarf planets at the moment. Here's a brief tour of all five ...