Neptune
Judging by the color of its atmosphere, the sky of Neptune is probably an azure or sky blue, similar to Uranus's. It is unlikely that the planet's rings can be seen from its surface, as they are very thin and dark.
Aside from the Sun, the most impressive object in Neptune's sky is its large moon Triton, which would appear slightly smaller than a full Moon on Earth. It moves more swiftly than our Moon, because of its shorter period (5.8 days) compounded by its retrograde orbit. The smaller moon Proteus would show a disk about half the size of the full Moon. Surprisingly, Neptune's small inner moons all cover, at some point in their orbits, more than 10' in Neptune's sky. At some points, Despina's angular diameter rivals that of Ariel from Uranus and Ganymede from Jupiter. Here are the angular diameters for Neptune's moons (for comparison, Earth's moon measures 31' for terrestrial observers): Naiad, 7–13'; Thalassa, 8–14'; Despina, 14–22'; Galatea, 13–18'; Larissa, 10–14'; Proteus, 12–16'; Triton, 26–28. An alignment of the inner moons would likely produce a spectacular sight. Neptune's large outer satellite, Nereid, is not large enough to appear as a disk from Neptune, and is not noticeable in the sky. The irregular outer moons would not be visible to the naked eye.
Read more about this topic: Extraterrestrial Skies
Famous quotes containing the word neptune:
“His nature is too noble for the world;
He would not flatter Neptune for his trident,
Or Jove for’s power to thunder.”
—William Shakespeare (1564–1616)
“But we are spirits of another sort.
I with the morning’s love have oft made sport,
And like a forester the groves may tread
Even till the eastern gate, all fiery-red,
Opening on Neptune with fair blessèd beams,
Turns unto yellow gold his salt green streams.”
—William Shakespeare (1564–1616)