What is Neptune's perihelion and aphelion?

1 Answer
Mar 11, 2016

4444.5 Million km and 4545.7 Million KM


Semi-major axis of Neptune's orbit a = 4495.1 Million km. Eccentricity of the orbit e = 0.011257, nearly.

Reference: NASA Planetary Fact Sheet.
Some other sources might give data differing slightly, in the least significant digits (lsd)..