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The Planet Neptune is the eighth
planet from the sun. It is also known as the Blue Giant. Neptune is the fourth and outermost of the gas giant planets and also has rings.
Its atmosphere is mostly hydrogen and helium. In Roman mythology Neptune was the
god of the Sea.
HAPPY BIRTHDAY PLANET NEPTUNE
On 12 July 2011, Planet Neptune celebrated its first birthday since its
discovery on 24 Sept 1846. It was exactly 1 Neptunian year (164.79 Earth years)
on its birthday.
Neptune has been visited
by only one spacecraft, Voyager
2 on Aug 25 1989. It
was the last stop in 1989 for the Voyager 2 spacecraft on its grand tour of the
solar system. Recent knowledge has been
gained by ground-based telescopes and the Hubble Space Telepscope.
Due to Pluto's eccentric orbit, Neptune at times
becomes the most distant planet from the Sun for a few years.
Planet Neptune Facts:
Mass: 17.15
Earth-masses
Number of known
satellites: 13
Length of Year:
164.8 Earth-years
Mean Distance from the Sun:
4,500 million kilometers
Mean Orbital Velocity: 5.4 kilometers per second
Length of Day: 16.11 hours, 0.67 Earth-day
Equatorial diameter:
49,500 kilometers
Atmospheric components:
74% hydrogen, 25% helium, 1% methane
Moons of Planet Neptune
Neptune has 13 known moons: Triton, Thalassa,
Naiad, Despina, Galatea, Larissa, Proteus and Nereid
Triton has the coldest temperatures in the
solar system. Voyager observed geysers.
Name
Neptune is named
after the Roman god of the sea.
The Great Dark Spot
Voyager 2 observed the Great Dark Spot. Recent
observations made with the Hubble Space Telescope indicate that the Great Dark
Spot no longer exists.
Atmosphere
Neptune's atmosphere is made up of hydrogen,
helium, and methane. Like Earth's atmosphere, Neptune's has clouds and storm
systems that revolve around the planet, but with wind speeds of 300 m/sec (700
miles/hr) and clouds of frozen methane.
Rings
Neptune has six rings which circle the planet.
Neptune's rings have been given names: the outermost is Adams (which contains
three prominent arcs now named Liberty, Equality and Fraternity), next is an
unnamed ring co-orbital with Galatea, then Leverrier (whose outer extensions are
called Lassell and Arago) and finally the faint but broad Galle.
History
In 1613 Galileo observed Neptune when it
happened to be very near Jupiter, but he thought it was just a star. Neptune was
first observed by Johann Galle and Heinrich D'Arrest 23 September 1846
Sept 23 very near to the locations independently predicted by Adams and Le
Verrier from calculations based on the observed positions of Jupiter, Saturn and
Uranus.
On 12 July 2011, Planet Neptune celebrated its
first birthday since its discovery on 24 Sept 1846. It was exactly 1 Neptunian
year (164.79 Earth years) on its birthday.
Books:
The Neptune File by
Tom Standage
From Amazon.com,
Amazon.co.uk
Neptune: The Eighth Planet (Countdown to Space) by
Michael D. Cole
From Amazon.com,
Amazon.co.uk
Did
you know?
Neptune is the smallest of
the four gas giants in our Solar System.
The Planet Neptune Links:
References:
Any suggestions or
comments, click on Contact
Info.
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