This hypothesized ninth planet (not you, sorry Pluto) might explain the unusual commonalities of extreme trans-Neptunian objects (ETNOs) 100s of AU from the sun. These ETNOs (such as dwarf planets and sednoids) have remarkably aligned orbits, suggest the existence of an undiscovered celestial body, dubbed Planet Nine, influencing them gravitationally.
Back in my day is was called Planet X. Sad
Musk ruined the mystique of that letter
I thought Planet X was a hypothetical inner planet?
Nah, it’s the same thing. Just renamed to planet nine now.
Well without Pluto it would be planet 9 not 10
X is so much more than just the Roman numeral.
I know right. Why do they always have to rename stuff. Isn’t there enough new stuff to name?