The Windy Blue Giant
Neptune
The most distant planet, a deep-blue ice giant whipped by the fastest winds ever measured. Discovered by mathematics before it was seen by telescope, Neptune marks the edge of the planetary realm.
Size compared to Earth3.88× Earth's diameter
Full bar = Jupiter, the largest planet
Vital statistics
- Diameter
- 49,528 km
- Distance from Sun
- 4495.1 million km
- Orbital period
- 165 Earth years
- Day length
- 16.1 hours
- Moons
- 16
- Mean temperature
- -200°C
Notable facts
Winds on Neptune reach 2,100 km/h — the fastest in the solar system, faster than the speed of sound on Earth.
Neptune was found in 1846 by predicting where an unseen planet must be from Uranus's wobble.
One Neptune year lasts 165 Earth years — it has completed just one orbit since its discovery.
Its large moon Triton orbits backwards and may be a captured object from the Kuiper Belt.
Next stop
Mercury