neptune can not be seen by just looking at the sky with the naked eye. to see it, a telescope or binoculars is needed. this is because neptune has a normal brightness between magnitudes +7.7 and +8.0. it can be out-shined by jupiter's galilean moons, the dwarf planet ceres, and the asteroids 4 vesta, 2 pallas, 7 iris, 3 juno and 6 hebe. a telescope or strong binoculars will show neptune as a small blue dot that looks similar to uranus. the blue color comes from the methane in its atmosphere. its small size in the night sky has made it difficult to study visually. most telescopic data was quite limited until the arrival of the hubble space telescope and large ground-based telescopes with adaptive optics.