Emerald Robinson: Hi, I am Emerald Robinson in this "What Is" video, we'll take a look at stormy, blue Neptune.
Neptune is the eighth planet in our solar system, and is named for the Roman god of the sea. It's also the most distant planet from the sun, a distinction it won when Pluto was demoted to the status of "dwarf planet" in 2006. Neptune was also the first planet to have its existence predicted by mathematical calculations, before it was actually seen by a telescope. Neptune is about 2.
7 billion miles from Earth. It has 13 known moons, and is similar in size to Uranus, making it the smallest of the four gas giant planets in the outer solar system. Neptune's atmosphere contains hydrogen, helium and methane, giving it a blue color that is largely the result of the absorption of red light by the methane in the atmosphere.
Neptune's gravity is slightly stronger than Earth's. A 100 pound person on Earth would weigh 114 pounds on Neptune. Like the other planets, Neptune has an elliptical orbit. It is 2.
8 billion miles from the sun on average, and takes 165 Earth years to complete a single orbit. In 2011, it completed its first full orbit of the Sun since its discovery in 1846. A day on Neptune, or one revolution on its axis, takes about 16 Earth hours. Neptune's surface temperatures can reach a frigid -392 degrees F. But in the core of this icy planet, you'll find temperatures comparable to the surface of the Sun. This huge temperature difference between the core and the surface helps create the strongest winds in the solar system - reaching speeds of 1200 to 1500 miles per hour.
NASA's Voyager 2 revealed some intriguing new features on its visit to Neptune in 1989. It showed six rings of varying thicknesses, a giant storm called the "Great Dark Spot," and a patch of cloud called "the scooter" because it circled the planet very fast. In 1994, the Hubble telescope discovered that the dark spot found in 1989 had disappeared and another dark spot had developed. Distant and cold, Neptune continues to reveal secrets and mysteries yet to be unraveled.