Depends on what you mean by Planet X. There's a legit search for another large ice giant in the far reaches of the outer solar system. https://solarsystem.nasa

Depends on what you mean by Planet X. There's a legit search for another large ice giant in the far reaches of the outer solar system. https://solarsystem.nasa.gov/planets/hypothetical-planet-x/in-depth/ https://solarsystem.nasa.gov/planets/hypothetical-planet-x/i...