Completed Orbit

This year, Neptune will complete its first orbit around the sun since its discovery.

Because Neptune is 30 times farther away from the Sun than Earth, a year there is ridiculously long. One year on Neptune (one revolution around the Sun) is equal to almost 165 Earth years! Neptune was first discovered in 1846, and in August 2011 an entire Neptunian year will have passed since then. This will also be during Neptune's Opposition, the best time to see the planet from Earth.


Technically, Neptune was first observed before 1846. Galileo first found Neptune in 1612 and mistook it for a star. We know now that he was actually looking at Neptune. In 1846, Galle used a telescope to locate Neptune using calculations from other astronomers that approximated where an 8th planet should be. Since then, we have been able to observe Neptune with the Voyager 2 spacecraft.

Read more about the history of Neptune's discovery.