Interstellar objects like 3I/ATLAS that have been captured in planet-forming disks around young stars could become the seeds of giant planets, bypassing a hurdle that theoretical models have ...

It's far out, man – literally. Researchers have uncovered the most-distant celestial object in the solar system, a pink dwarf planet nicknamed "Farout," detect at a distance of more than 100 times ...

There are officially eight planets in our Solar System — yes, I know, Pluto was totally a planet, but not anymore — but that doesn’t mean there isn’t something lurking on the edge of our system that ...

Just because Pluto was ruled out as a planet in 2006 doesn’t mean our solar system only has eight planets. The search for Planet Nine is far from over as scientists continue to uncover clues ...

While searching for the mysterious Planet X that some astronomers believe lurks on the edge of our solar system, researchers instead found an extremely distant object they dubbed “the Goblin.” And ...

Move aside, Sedna and 2012 VP113. There's a new most distant object in our solar system, and it strengthens the hypothetical case for an unseen large planet at the outer boundaries of our solar system ...

In a twist that surprised many astronomers, the definition of planet recently adopted by the IAU is not meant to apply to objects around other stars. Also, it does not take formation history into ...

The case for Planet Nine is growing. Two new findings presented at a planetary science meeting in Pasadena have uncovered hints for the existence of this distant, mysterious world in the motions of ...