Neptune
Neptune
Planet · 30.07 AU from the Sun
Neptune facts
- Type
- Planet
- Distance from the Sun
- 30.07 AU (4.5 × 10⁹ km)
- Orbital period (year)
- 165 Earth years
- Diameter
- 49,244 km
- Mass
- 1.02 × 10²⁶ kg
- Moons
- 16
- Rotation period (day)
- 16.1 hours
- Axial tilt
- 28.32°
- Mean temperature
- -200 °C
- Discovered
- 1846, by Le Verrier, Galle and Adams
Orbit
About Neptune
Neptune is the eighth and most distant planet, a deep-blue ice giant with the fastest winds in the Solar System, exceeding 2,000 km/h. It was the first planet found by mathematical prediction rather than observation, from the way it tugged on Uranus's orbit.
- Named after the Roman god of the sea
- Discovered: 1846, by Le Verrier, Galle and Adams
Major moons of Neptune
Neptune has 16 known moons; its largest is shown below. Press play to start the animation.
Relative sizes and spacing are compressed; orbits shown coplanar. Click a moon for its page.
Paused
Neptune: frequently asked questions
- What is Neptune?
- Neptune is a planet in our Solar System, orbiting the Sun at an average distance of 30.07 AU (4.5 × 10⁹ km). Neptune is the eighth and most distant planet, a deep-blue ice giant with the fastest winds in the Solar System, exceeding 2,000 km/h.
- How far is Neptune from the Sun?
- Neptune orbits the Sun at an average distance of 30.07 AU, about 4.5 × 10⁹ km. One AU is the Earth-Sun distance, so Neptune is roughly 30.1 times Earth's distance from the Sun.
- How long is a year on Neptune?
- Neptune takes 165 Earth years to complete one orbit of the Sun. By Kepler's third law, bodies farther from the Sun take longer to go around.
- How many moons does Neptune have?
- Neptune has 16 known moons; the largest is Triton.
- How big is Neptune?
- Neptune has a diameter of about 49,244 km and a mass of roughly 1.02 × 10²⁶ kg.
See Neptune in motion
Data from NASA/JPL and NSSDCA. Source.