Neptune takes approximately 164.8 to 165 Earth years to complete one orbit around the Sun. This corresponds to about 60,190 Earth days for a full Neptunian year
. Key details about Neptune's orbit include:
- Average distance from the Sun: about 4.5 billion kilometers (30.1 astronomical units)
- Orbital eccentricity (how elliptical the orbit is): very low, about 0.0086 to 0.0097, making it nearly circular
- Orbital speed: roughly 5.43 km/s
- Neptune has completed only one full orbit since its discovery in 1846, which it achieved around 2011
In summary, a Neptunian year lasts nearly 165 Earth years due to its great distance from the Sun and slow orbital speed.
