New discoveries of objects in the Kuiper Belt have also presented challenges for the Planet Nine theory. The latest is known ...

A new study suggests the existence of Planet Y. This hidden planet may be affecting the Kuiper Belt. The gravity of Planet Y could be causing a tilt in the orbits of some icy objects. Researchers ...

Astronomers propose a new hypothetical planet, Planet Y, beyond Neptune, based on observed orbital anomalies in the Kuiper ...

For years, astronomers have searched the outer reaches of our solar system for Planet 9, a theoretical planet that could ...

In October 2017, NASA released a statement saying that Planet Nine may be 20 times further from the Sun than Neptune is, going so far as to say "it is now harder to imagine our solar system ...

If Planet 9 is real, this observatory has around a 70 to 80 percent chance of finding it, he estimates, adding that it's not a sure thing because there are so many uncertainties.

Planet 9 likely isn't a stolen exoplanet after all. New research shows the probability of ideal planet-swapping positions between young stars is near zero.

A team led by Amos Chen from the National Tsing Hua University, is searching for Planet Nine’s heat signature. When you double the distance from the sun, reflected light becomes 16 times fainter. This ...

“So, in principle, Planet Nine can be a planet, a potato, a black hole, a hamburger, etc., as long as its orbital parameters are right.” Though Batygin isn’t entirely convinced a black hole roaming ...

A star already known to host five alien planets may actually be home to a whopping nine full-fledged worlds - a planetary arrangement that, if confirmed, would outnumber our own solar system and ...

"Planet Nine is expected to generate some highly inclined TNOs, and BP519 is consistent with this picture," Becker said. "The findings are not 'proof,' but circumstantial evidence." ...