Planet 9 sits at the edge of scientific imagination, promising either an epic expansion of the Solar System or a lesson in ...

Far beyond Neptune, something heavy appears to be tugging on the outer solar system, bending the paths of distant icy worlds in ways gravity alone should be able to explain. Planet 9, still invisible ...

Astronomers believe there is a Planet Nine in the outer solar system beyond Neptune. A team led by Amos Chen from the National Tsing Hua University, is searching for Planet Nine’s heat signature. When ...

After studying thousands of computer simulations of the solar system, researchers at Rice University and the Planetary Science Institute think there’s a 40% chance an elusive “Planet Nine” or “Planet ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. An object has been discovered orbiting the sun far beyond ...

A newly discovered dwarf planet called 'Ammonite' (2023 KQ14) has been spotted in the outer solar system, and it could be another nail in the coffin for the Planet Nine hypothesis. When you purchase ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

Astronomers have discovered a new member of a rare and mysterious class of solar system objects known as sednoids — a subset of extreme trans-Neptunian objects (ETNOs) with exceptionally distant, ...

There has been a lot of back and forth about the existence of a mysterious ninth planet, often referred to as "Planet Nine" or even "Planet X." Now, though, researchers say there is likely at least a ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...