User:SoylentPurple/sandbox

This is a list of known observations of planets or dwarf planets that occurred before the discovery of the body. In each case, the observer did not recognize that the object was a planet.

Uranus
Uranus is noticeably dimmer than the other classical planets, yet is still visible to the unaided eye in a dark sky.

Neptune
Neptune is too dim to be seen without optical aid so no observations were possible before the invention of the telescope.

Pluto
Observing Pluto requires, at minimum, a telescope with an aperture of around 30 cm (12 inches). All of these observations were photographic ones.