The newly discovered world — a "sednoid" — challenges what planetary scientists thought they knew about the edge of the solar ...

The celestial body's unusual orbit “implies that something extraordinary occurred" in the early days of the solar system—and ...

Astronomers have hoped for the existence of Planet Nine for years. Things were looking promising, but this discovery might ...

Would one frozen world, just visible on the rim of the Sun’s kingdom, turn decades of speculation on the concealed layout of ...

In 2003, NASA-funded researchers spotted what was then the most distant object discovered in our Solar System. The dwarf ...

"It is possible that a planet once existed in the solar system but was later ejected, causing the unusual orbits we see today ...

Typically, telescopes are synonymous with bringing far-off objects close, but the newest member of the solar system was discovered using wide-field imaging. The Subaru Telescope has spotted a distant ...

Astronomers have discovered a "fossil" world lying in the outskirts of the solar system, according to new research.

Researchers just got a step closer to understanding the origins of our solar system, with the discovery of an object orbiting ...

A newly found icy object, Ammonite, may be a 4-billion-year-old fossil from the Solar System’s edge—and it’s casting doubt on ...

Learn more about a sednoid called Ammonite that has been detected in the outer reaches of the Solar System.

The Subaru Telescope has revealed a fourth member of the sednoids, a group of small bodies with peculiar orbits around the ...