[NorthMountain]

Pluto and Neptune were both discovered after educated speculation suggested where to look for them. Pluto was deposed from planethood on account of being in an orbit full of debris. Hypothetical “Planet X”, when and if found, will be judged by the same criteria.

[Capt. Tom]

Pluto and Neptune were both discovered after educated speculation suggested where to look for them.

Those were successes, but Vulcan has not been found, and I guess they gave up on that search. -tom