It Takes Neptune More Than A Century To Complete One Orbit

Neptune completed its first full orbit around the sun, at least since the planet was discovered, on July 12, 2011. NASA's Hubble Space Telescope took photos of the planet to commemorate the occasion, timing the snapshots so that they captured all of Neptune's sides during its 16-hour rotation. When Neptune was discovered in 1846, it doubled the size of the known solar system, creating a boundary at 2.8 billion miles (4.5 billion kilometers) from the sun. Its seasons last the longest of any planet's in the solar system, and are a stark counterpoint to Mercury's, which shift so quickly that it's impossible to determine when one ends and another begins. Learn more about Neptune and other neighboring planets with the videos below.

Facts About The Planets

Interesting tidbits about each planet in our Solar System, plus Pluto and the asteroid belt.

Key Facts In This Video

  1. Planets, asteroids, and other matter make up only .14% of the solar system's mass. 00:06

  2. Pluto won't complete its next full orbit around the sun until the year 2177. 01:01

  3. Jupiter might contain water droplets in certain gas layers. 02:45

Neptune And Its Moons

Scientists talk about the eighth planet and its moons.

Key Facts In This Video

  1. Neptune's existence was predicted after scientists noticed that something was affecting the orbit of Uranus. 00:16

  2. Neptune's moon, Triton, is unique because it orbits Neptune in the opposite direction of the planet's spin. 01:38

  3. Triton was discovered by an amateur astronomer who owned a brewery. He used his beer profits to fund his telescopes. 03:07

Exploring Uranus and Neptune

Learn about the only two planets in the Solar System that are invisible to the naked eye.

Written by Curiosity Staff December 14, 2015

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