Planet Neptune

Neptunian Glossary

AphelionThe Aphelion occurs when a planet is furthest to the Sun during its slightly elliptical orbit.Aphelion
Aphelion of Earth
NeptuneNeptune is usually the eight planet from the Sun although it is sometimes 9th when Pluto moves within it's orbit. Neptune's diameter is 49,500 km and takes 165 years to orbit the Sun. Neptune is named after the Roman god of the sea. Neptune was discovered on September 23, 1846 by French astronomer Urbain Le Verrier.
NeptunianHaving to do with the planet Neptune.
NereidThe smallest moon of Neptune was discovered by Gerard Kuiper in May 1, 1949. Nereid is also designated as "Neptune II". In Greek mythology, the Nereid were sea-nymphs.
OppositionFor planets outside the Earth's orbit (Mars, Jupiter, Saturn, Uranus, Neptune and Pluto), the months around Oppositions are the best time to view these. An Opposition occurs when the planet is opposite from the Sun, relative to the Earth. At Opposition the planet will rise as the Sun sets and will set as the Sun rises providing an entire night of observation. Also at Opposition the planet comes physically closest to the Earth in it's orbit so it appears as large as possible.Opposition
PerihelionThe Perihelion occurs when a planet is closest to the Sun during its slightly elliptical orbit.Perihelion
Perihelion of Earth
ProteusThe second-largest, moon of Neptune was discovered by Stephen P. Synnott on June 16, 1989. Proteus is also designated as "Neptune VIII" and "S/19989 N1". In Greek mythology, Proteus was the shape-changing sea god.
TritonThe largest moon of Neptune was discovered by William Lassell on October 10, 1846. Triton is also designated as "Neptune I". In Greek mythology, Triton was a sea god and the son of Neptune.
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