NEPTUNE
Planet No. 8 • The Windy Blue Giant
Welcome to the Neptune information file! Neptune is the eighth and farthest major planet from the Sun. This deep blue ice giant is a cold, distant world with enormous storms, faint rings and the fastest planetary winds known in our solar system.
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PLANET OVERVIEW
Neptune is an ice giant made mostly of hydrogen and helium, with large amounts of water, ammonia and methane deeper inside the planet. Methane in its atmosphere absorbs red light and contributes to its blue appearance.
Neptune receives very little sunlight because it is so far from the Sun, yet its atmosphere is surprisingly active. Huge storms and extremely powerful winds race through its clouds.
Neptune receives very little sunlight because it is so far from the Sun, yet its atmosphere is surprisingly active. Huge storms and extremely powerful winds race through its clouds.
☀ LOCATION
Neptune is the eighth major planet from the Sun. Its average distance from the Sun is about 2.8 billion miles.
SIZE
Neptune has a diameter of about 30,600 miles. It is nearly four times wider than Earth.
STORMS
Neptune can develop enormous dark storms in its atmosphere. These storm systems can appear, change and disappear over time.
☁ ATMOSPHERE
Neptune's atmosphere is mostly hydrogen and helium with methane. Clouds of methane ice and other materials form high in the planet's atmosphere.
✦ NEPTUNE FAST FACTS ✦
| Position from Sun | 8th planet |
| Planet Type | Ice Giant |
| Length of Year | About 165 Earth years |
| Length of Day | About 16 hours |
| Moons | Many known moons, including Triton, Nereid and Proteus |
| Rings | Yes — several faint, dark rings |
| Diameter | About 30,600 miles |
| Average Distance from Sun | About 2.8 billion miles |
| Famous Feature | Extremely powerful winds and giant storms |
WHAT IS NEPTUNE LIKE?
Neptune is one of the coldest and windiest places in the solar system. Temperatures in its upper atmosphere can fall below -350°F.
Winds on Neptune can travel faster than 1,000 miles per hour, making them the fastest known planetary winds in the solar system.
Neptune has also been observed with enormous dark storm systems. Voyager 2 photographed a huge storm called the Great Dark Spot during its 1989 flyby. Later observations showed that large storms on Neptune can appear and disappear over time.
Winds on Neptune can travel faster than 1,000 miles per hour, making them the fastest known planetary winds in the solar system.
Neptune has also been observed with enormous dark storm systems. Voyager 2 photographed a huge storm called the Great Dark Spot during its 1989 flyby. Later observations showed that large storms on Neptune can appear and disappear over time.
★ DID YOU KNOW? ★
Neptune was discovered using mathematics before it was directly observed! Astronomers noticed that Uranus was not moving exactly as expected and predicted that another planet's gravity might be affecting it. Neptune was then observed near the predicted location in 1846.
Neptune was discovered using mathematics before it was directly observed! Astronomers noticed that Uranus was not moving exactly as expected and predicted that another planet's gravity might be affecting it. Neptune was then observed near the predicted location in 1846.
SPACECRAFT MISSION LOG
> DESTINATION: NEPTUNE
> VOYAGER 2
Voyager 2 became the first and so far only spacecraft to visit Neptune when it flew past the planet in 1989.
> DISCOVERIES
Voyager 2 photographed Neptune's clouds, storms, rings and moons. It discovered several new moons and returned detailed images of Triton.
> TRITON
Voyager 2 observed strange icy terrain and active geyser-like plumes on Neptune's largest moon, Triton.
> CURRENT OBSERVATIONS
Astronomers continue to study Neptune with powerful telescopes, watching its storms, clouds, atmosphere and changing weather patterns.
> STATUS:
FUTURE MISSIONS TO NEPTUNE ARE BEING STUDIED...
> VOYAGER 2
Voyager 2 became the first and so far only spacecraft to visit Neptune when it flew past the planet in 1989.
> DISCOVERIES
Voyager 2 photographed Neptune's clouds, storms, rings and moons. It discovered several new moons and returned detailed images of Triton.
> TRITON
Voyager 2 observed strange icy terrain and active geyser-like plumes on Neptune's largest moon, Triton.
> CURRENT OBSERVATIONS
Astronomers continue to study Neptune with powerful telescopes, watching its storms, clouds, atmosphere and changing weather patterns.
> STATUS:
FUTURE MISSIONS TO NEPTUNE ARE BEING STUDIED...