Neptune
Introduction
Neptune is actually the last
planet in the solar system right after Uranus, as Pluto is now classified as a
dwarf and is no longer a planet. The name of the planet comes from the Roman
god, Poseidon, who was the god of the sea. Like most of the other Outer Planets,
which have been visited by only one spacecraft, Voyager 2 is the only mission to
have flown to Neptune on the 25th of August 1989. Neptune has 13 known moons.
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Surface and Contents
Neptune is a very dense planet. Its core alone is almost as dense as the Earth.
The planet is almost entirely made up of rock and ice. The planet also contains
a little bit of hydrogen, methane and helium. The surface of Neptune appears
blue because of the methane, but astronomers are not sure whether it is the
reason of methane alone. One of the most interesting features of the surface of
Neptune which is almost as large as the Earth. In 1994, though, astronomers have
discovered that the Great Dark Spot isn’t there any more. Neptune has rings but
they are very faint. However, we don't know what these rings are made up of.
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Triton
Triton is the son of Neptune in Greek mythology. Practically all the information
that we have of Triton comes from just one mission: The Voyager2 that flew past
on the 25th of August, 1989. Triton is one of the few moons that orbit their
planet backwards. Such an orbit is known as a retrograde orbit. Because of
orbiting backwards, Triton is being pulled closer and closer to Neptune. Soon,
Triton will soon smash right into Neptune or break up into pieces and form a
ring. Triton also has a strange form of rotation which is almost horizontal, at
157 degrees.
Contents:
Unlike most of the other moons of the Outer Planets which are almost completely
made up of ice, Triton contains 75% of rock and only about 25% of ice.
Triton’s surface is reflective one. This means that it reflects even the little
bit of light that reaches it from the sun. Therefore temperatures at its surface
are extremely low, around 34.5 K (-235 C, -391 F) which is cold enough to freeze
carbon dioxide and nitrogen into solids. Triton’s surface is also very smooth.
It does not have many craters and has a smooth surface. The surface of Triton is
dominated by valleys and cliffs, which were probably created by the freezing and
melting of ice which would have cracked the rock.
Volcanoes
The most remarkable and surprising thing about the surface of Triton is the
presence of volcanoes. The volcanic fluid is liquid nitrogen. This comes when
the frozen nitrogen melts when heat comes from the sun once in a while. The only
bodies in the solar system that have been found with active volcanoes are:
Venus, Earth, Io and Triton.
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Did You Know?
1. Neptune’s orbit is one of the most awkward orbit in the solar system. It
crosses the orbit of Pluto, a dwarf planet once in while for a few years
increasing its distance from the sun by an incredible amount.
2. Neptune’s atmosphere is very active. There are extremely fast winds, and new
features of the atmosphere are appearing and disasppearing every day.
3. Neptune has 13 known moons; 7 small named ones and Triton plus four
discovered in 2002 and one discovered in 2003 which have yet to be named.
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