Hobbies And Interests
Size
The diameter of Neptune is 30,775 miles, which makes it about four times as large as Earth. The planet lies at an average distance of 2.795 billion miles from the Sun. At its closest, Neptune is 2.77 billion miles away from the sun; and at its farthest, it is 2.819 billion miles away from the sun. The surface area of Neptune is 2.95 billion square miles, making it almost 15 times larger than Earth.
Time Frame
The enormous distance that Neptune is from the Sun means that an astounding length of time is required to complete one full revolution around it. Neptune takes 164.79 Earth years to make this long journey, which translates into 60,190 days. Neptune spins on its axis one complete turn in 16.11 hours, or about two-thirds of what Earth needs to do so. Neptune was discovered in 1846 when mathematicians noticed that Uranus, the furthest known planet at that time, was behaving unpredictably in its orbit, meaning it was possibly being influenced by a larger body. Two individuals, an Englishman named John Adams and a French math whiz named Urbain LeVerrier, accurately predicted where Neptune would be. Johann Galle and his assistant, Heinrich d'Arrest, found the planet where LeVerrier's calculations said it would be on September 23, 1846; both LeVerrier and Adams were given equal credit for the find.
Geography
The surface of Neptune in no way resembles that of the Earth's. Compressed gases, most likely hydrogen and helium mixed with water, form the first layer, which gradually gives way to a thicker liquid layer and then finally a rocky core. The atmosphere of Neptune is comprised of clouds of frozen methane and possibly hydrogen sulfide. Neptune has fierce winds that blow as hard as 700 miles per hour. The clouds give Neptune a bluish tint when it is viewed through a telescope.
Features
As of this June 2009 writing, 11 satellites that orbit Neptune have been discovered. Triton is the largest of these, with a diameter of 1,681 miles. It is some 220,440 miles from Neptune, and it is the coldest place in the solar system with a temperature of minus 390 degrees F. Neptune, like Saturn, Jupiter and Uranus, possesses rings that encircle the planet. However, these rings, which are apparently composed of dust particles, are very faint.
Expert Insight
Pluto is normally the farthest of the planets and dwarf planets from the Sun, with the exception of a 20-year span that occurs every 248 years. During this time, Pluto will actually move inside of Neptune's orbit and promote Neptune into the role of the farthest-away planet. This is due to the oval-shaped nature of Pluto's orbit, which brings it into this position.