Hypothetical Planet 9 accounts for the movement of several trans-Neptunian ... We know there isn’t a Mars-sized planet orbiting between Jupiter and Saturn nor a brown dwarf nemesis heading our way.

Planet 9 is 47K, but if it weren't for its core it would be 10K, meaning the majority of its thermal energy comes from inside the planet. Image source, E. Linder/C. Mordasini/University of Bern ...

Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart; ... "PSA: Planet Nine is not Planet X or Nibiru or Nemesis.

Almost a decade after astronomers proposed the existence of Planet 9, an unseen extra planet in the distant reaches of the solar system, they still haven’t all agreed whether it’s real or not ...

Planet 9 may be closer and easier to find than thought—if it exists. A new study's "treasure map" suggests that a planet several times more massive than Earth could be hiding in our solar system ...

"If Planet 9 is anomalous in some respect, there could be more interest in expediting such a mission." It is also possible that a private space exploration company, such as SpaceX, ...

A team of researchers say they have found the "strongest statistical evidence yet that Planet 9 is really out there", after studying a population of distant, unstable objects that cross Neptune's ...

The hunt for Planet 9 was part of a Zooniverse citizen science project, conducted in real-time, with the BBC’s Stargazing Live broadcast. The project was hosted at the Siding Spring Observatory ...

While Planet 9’s existence remains fully up in the air, more evidence could become available within a year or two, when a Chilean observatory that’s currently under construction opens, ...

Some scientists are convinced that beyond Neptune, there's a planet they've yet to see. This so-called "Planet 9" is so far away, it would be a faint object. The stretch of sky researchers would ...

Good news: we're all not going to die (yet). Some "news" reports have suggested a ninth planet (Planet 9) lurking at the edge of our solar system will soon be responsible for mass extinctions ...