Explore Neptune

Student Planet Facts

Neptune is the eighth planet in the solar system. Here are some facts and other places you can find information. When you are ready, click back to return to the Student Center or click below to explore again.

Neptune and its moon, Triton Blue Neptune is one of the solar system's gas giants. Unlike Earth, gas giants are mostly hydrogen, helium, and methane gases. The methane gas on Neptune gives the planet its blue color because the gas absorbs red light and reflects the blue back into space. Although not seen in the image the planet has a set of very faint rings.

The Great Dark Spot, the dark oval on the planet, was a storm like the Great Red Spot on Jupiter. The storm has disappeared since this image was taken by Voyager 2 according to Hubble Space Telescope data but another spot was found in a different place. The atmosphere shows lots of activity including the white clouds of methane ice crystals seen in the image at left.

The unusual texture of one of Neptune's moons, Triton, reminds some people of a cantaloupe. It is the largest moon to orbit retrograde (backwards) around a planet.

Neptune Moon Count Hits 13
Recently more moonlets have been found orbiting the planet, bringing its total to 13. Observers spotted them using large telescopes in Chile and Hawaii. They are the first Neptunian moons discovered since 1989 when Voyager 2 passed by. Their orbits indicate they may be from a collision between another moon and a large object.

Gravity and You
Your weight on Earth is determined by your mass and Earth's mass. Would you weigh more or less on Neptune?

Planet Names
Why are the planets named for Roman gods? What is the story or myth about their names? Click image or here for Planet Myths and Lore.

New! Click here to find out about "The Professor's Telescope", a new book by Chris Moreau, one of our advisors. Take an adventure with Eric to Saturn!

A portion of the proceeds will help support Kid's Cosmos.

Quick Facts about Neptune

Topic

Data

Diameter

49,572 km

Density

1.64 g/cm³

Mass

1.024 x 10²⁶ kg

Volume

6.379 x 10¹³ km³

Temperature Range

-223° C to >-220° C

Atmosphere

Hydrogen, Helium, Methane

Winds

Up to 2400 m/s

Moons

13

Average Distance from Sun

4,504,300,000 km

Orbital Period

164 Years, 288 Days, 13.0 Hours

Rotation

0 Days, 16.11 Hours

Tilt

28.31°

Rings

Yes

Composition

Hydrogen and Helium

Magnetic Field

Up to 20 times its radius

These links will take you to another website by opening a new window.
Close the window to return to Kid's Cosmos.

The Nine Planets
NASA Planet Facts
Voyager I and II Missions
Top
Back to Student Center

Kid's Cosmos...Expanding Minds Beyond the Limits of the Universe