Planet

Neptune

Ice giant · At the edge of the eight planets

The most distant of the eight planets, an ice giant with an atmosphere stirred by fast winds.

Prepare an observation This stop on the Solar System trail

Schematic illustration: Neptune — Educational illustration · shapes and sizes are not to scale.

Equatorial diameter: 49 528 km
Mean orbital distance: 4515,0 million km
Orbital period around the Sun: ≈ 165 ans

What makes this world interesting

Discovered in 1846 following mathematical predictions, Neptune has faint rings. Triton, its largest moon, stands out for its retrograde orbit.

Observe or explore it

Invisible to the naked eye, it requires a chart and an instrument. Its small disc is hard to distinguish from a star without sufficient magnification.

Connect the discoveries

Triton The Kuiper Belt Uranus

Sources and reference information

NASA Science — Neptune · NASA/NSSDCA — planetary data

Rounded educational data, sources consulted on 18 October 2026. Orbital distances are mean reference distances from the Sun, not current distances from Earth. Periods are expressed in Earth time. The planner provides date-specific positions for supported targets.

Understand its motion. Explore a simplified orbit in the laboratory →