Neptune takes about 16 hours to rotate once a Neptunian day , and about Earth years to orbit the sun a Neptunian year. Neptune is an ice giant.
Most of its mass is a hot, dense fluid of "icy" materials — water, methane and ammonia — above a small rocky core. Neptune's atmosphere is made up mostly of molecular hydrogen, atomic helium and methane. Neptune has 14 known moons which are named after sea gods and nymphs in Greek mythology. Neptune has at least five main rings and four more ring arcs, which are clumps of dust and debris likely formed by the gravity of a nearby moon.
Voyager 2 is the only spacecraft to have visited Neptune. No spacecraft has orbited this distant planet to study it at length and up close. Even though Neptune is the farthest planet from our Sun, it's a frequent stop in pop culture and fiction. The planet served as the backdrop for the science fiction horror film "Event Horizon," while in the cartoon series "Futurama," the character Robot Santa Claus has his home base on Neptune's north pole.
Who" fans will remember that an episode entitled "Sleep No More" is set on a space station orbiting Neptune. Neptune is dark, cold, and very windy.
It's the last of the planets in our solar system. The distance from one planet to another is constantly shifting because both bodies are moving through space. When Neptune and Earth line up on the same side of the sun, at their closest, they are only 2. But when the planets are on opposite sides of the sun, they can put as many as 2. Neptune's extreme distance made it the last full-size planet to be discovered. Unlike Uranus, it was found primarily by pouring over mathematical formulas rather than peering through a telescope.
Astronomers had noticed that the recently-discovered Uranus had some orbital oddities that could not be explained. John Couch Adams and Urbain Le Verrier independently calculated the planet's orbit between and , and several astronomers began to search for the proposed planet.
On September 23, , the icy body was found within one degree of Le Verrier's predictions and 12 degrees from where Adams suggested it would travel. This prompted discussion over who should be credited with the discovery, but ultimately both men were recognized for their roles.
The planet was spotted in and by Galileo Galilei. Unfortunately, the Italian astronomer made his observations when Neptune had just begun its backward, or retrograde, motion across the sky. Orbit Inclination.
Equatorial Inclination to Orbit. Mean Radius. Metric: 24, km. Equatorial Circumference. Metric: , Metric: 62,,,, km 3. Metric: ,,,,,,,, kg. Metric: 1. Surface Area. Metric: 7,,, km 2.
Surface Gravity. Because light travels at , miles per second and Neptune is 2. All things considered, then, it's pretty amazing that it took only 10 or so years for a spacecraft launched from Earth, Voyager 2, to reach Neptune after being launched in The discovery of Neptune itself reveals the elegant nature of science and cooperation between people in different disciplines. A 19th-century French mathematician named Urbain Joseph Le Verrier suspected that a planet had to exist outside the orbit of Uranus owing to perturbation's in the orbit of Uranus that could only have come from an object large enough to exert small gravitational effects on Uranus.
He submitted his ideas to the French astronomer Johann Gottfried Galle in Germany, who discovered Uranus on his first night of searching. It was only 17 days later that Neptune's largest moon, Triton, was found.
The much-anticipated Voyager fly-by of Neptune offered humans the first close-up look at the planet. The spacecraft revealed six previously unknown moons; at the time of Voyager's fly-by, Triton was the only known Neptunian natural satellite. Triton, the sixth-largest moon in the solar system, is a wonder unto itself.
Voyager revealed that the moon has both volcanic activity and seasons of its own, and Triton is an oddity in that it revolves around Neptune in the direction opposite of that in which Neptune rotates, a seeming gravitational contradiction.
Voyager 2 also found a semi-permanent storm large enough to contain the entire Earth swirling away on Neptune's surface, dubbed "The Great Dark Spot" a tribute of sorts to the famed Great Red Spot of Jupiter. This storm boasted winds in excess of 1, miles an hour, the fastest known in the solar system. Kevin Beck holds a bachelor's degree in physics with minors in math and chemistry from the University of Vermont.
Formerly with ScienceBlogs.
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