Neptune is the eighth planet from the sun in this solar system. Only once has a spaceship been sent to orbit it, but with advanced telescopes, ongoing observations reveal new information on a regular basis. This allows scientists to make predictions about things like the average temperature on Neptune.
Identification
Neptune is the farthest planet from the sun in the solar system with the exception of Pluto. Actually, the orbits of the eighth and ninth planets cross so that Neptune is the farthest planet from the sun for a part of every Neptune year. It was named after the Roman god of the sea and first observed by Galileo in 1613, even though he did not realize that it was a planet. The astronomers, Galle and d'Arrest recorded the observations that led them to conclude that Neptune is a planet on September 23, 1846.
Features
Neptune has a diameter of 30,775 miles at its widest point, the equator. It also has 13 moons in all, of which 7 are named. Neptune also has 4 rings. Since it tilts on an axis, the planet experiences seasonal changes during its annual rotation around the sun. It is also reported to have the fastest winds in the solar system. Winds of up to 700 miles per hour have been observed.
Considerations
Neptune looks blue. This is because its atmosphere is made of frozen methane gas that absorbs the red light out of the spectrum. Neptune's atmosphere also contains about 15 percent hydrogen as well as some hydrogen. The planet itself is thought to be comprised of hydrogen, helium, water and silicates.
Expert Insight
NASA's Voyager 2 arrived at Neptune on August 25, 1989. This exploratory unmanned flight sent back photographs of Neptune to scientists on earth. Using the pictures and other data provided by Voyager 2, scientists identified a Great Dark Spot on Neptune's surface. They also learned a great deal about Neptune's four rings. The Hubble Space Telescope has been used to add to this information. This telescope helped astronomers to determine that Neptune's atmosphere undergoes rapid changes. In 1994, the Hubble Space Telescope observers could not locate the Great Dark Spot anywhere.
Theories/Speculation
In 2007, NASA scientist, Glenn Orton, used the European Organization for Astronomical Research's Very Large Telescope in Chile to make even more observations about Neptune. He was able to make temperature maps of Neptune using thermal images. In a report published in "Astronomy & Astrophysics" Orton wrote that the hottest point on Neptune is at the South Pole. It is about 18 degrees Fahrenheit hotter than elsewhere on the planet. He also stated that the planet's average temperature is minus 382 degrees Fahrenheit. Not only is Neptune heated by the sun, it radiates its own heat as well.
Tags: planet from, solar system, that Neptune, about Neptune, average temperature, Dark Spot, degrees Fahrenheit
