It's dark out there! At Neptune's distance, the sun appears less than 4% as bright as it does at Jupiter. So, Neptune is invisible from Earth to the naked eye and a challenge to detect even with a good pair of binoculars. At magnitude 7.7 and featuring a very tiny (2.5 arc second) bluish disk, at least a six-inch telescope and a magnification of 150X are required to reveal it as a planet.

Neptune's largest moon, Triton, shines with a magnitude of 13 and can be glimpsed in a six-inch telescope but only under near-perfect conditions.