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SOLAR
SYSTEM
STARS
BLACK
HOLES
METEORS
AND METEORITES
ASTEROIDS
COMETS
GALAXIES
NEBULAE
GLOSSARY
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Pluto:Frontier
of the Solar System
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| Name of
the Planet |
Pluto |
| Position
in Solar System |
Pluto is
the furthest planet from the Sun. It is named after the Greek
lord of the underworld. |
| Constituents |
icy, rocky
|
| Atmosphere |
methane
|
| Average
Distance from Sun |
5,900,000,000
km/3,666,000,000 mi |
| Orbit
Time |
248.5 Earth
years |
| Diameter |
2,320 km/1,440
mi |
| Average
Density (water=1) |
2 |
| Satellites |
Charon |
| Average
Surface Temp |
–223ºC |
| Rotational
Period |
6.39 days |
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Description:
Pluto is the last planet of
our Solar System.
Pluto follows the most elliptical orbit than any other planet. Part
of its orbit lies inside Neptune's orbit and until 2000 A.D. it
will stay nearer to the Sun than the Neptune.
Pluto lies at a mean instance of 5,900 million km from the Sun.
The planet Pluto is extremely difficult to observe from the Earth
because it is so distant and so small - it is only some 2,300 km
across i.e. about one and half times the size of Triton, Neptune's
largest satellite. Pluto's mass is equal to 0.22 percent of Earth.
The rotation period of Pluto is about 6 days and revolves around
the Sun in about 247.7 Earth years. According to one theory, Pluto
is an escaped satellite of Neptune which somehow broke free and
moved along in an independent orbit. The planet seems to be a snowball
of frozen gases, with a surface temperature of about -220 degree
C. Some scientists think they may have detected a thin atmosphere.
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| From Pluto the Sun
is like a tiny point of light but a point which is about 440 times
brighter than the full moon from the Earth. In 1978, James W. Christy,
of the US Naval Observatory, observed and discovered that Pluto has
a moon. He called it Charon. The diameter of Pluto is about 5,800
km and the diameter of Charon is believed to be about 1,200 km. Charon
is believed to orbit about 20,000 km above Pluto's crust. The closeness
and similarity in size of Pluto and Charon, make some astronomers
caonsider them as a double planet rather than a planet and satellite.
Ony a thin and hazy atmosphered has been detected arount Pluto. |
Image:Surface
of Pluto
Source : NASA/NSSDC
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Image:Pluto and Charon(Moon
of Pluto)
Source:NASA/NSSDC,
PRESS
RELEASE TEXT
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Interesting facts:
-On average, the Sun appears 1905 times fainter
at Pluto than it does from Earth.
-On January 2000, Pluto have travelled 20.14% of its orbit around
the Sun since its discovery.
-Pluto will not complete one post-discovery orbit until 8 August,
2178.
-Pluto and Neptune will never collide. They can never be less than
about 386000000 km from each other.
-Pluto may appear within the boundaries of 41 constellations.
-The escape velocity of Pluto is only 11% that of Earth.
-The Earth is 463 times as massive as Pluto.
-The surface gravity of Pluto is only 4.1% that of the Earth. |
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Historical Events
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| 6 April, 1929 |
US observing assistant Clyde
William T. took the first plate through the 33 cm A. Lawerence
Lowell Astrographic refractor. Thus began his search for the
planet. |
| 23 January, 1930 |
The first of the discovery
plates of Pluto was taken by Clyde Tombaugh. |
| 13 March, 1930 |
The discovery of Pluto was
announced. |
| 1954 |
Pluto's rotation rate was first determined.
|
| 1976 |
Spectroscopic analysis revealed
the presence of methane on Pluto. |
| 22 June, 1978 |
US astronomer James Christie
discovered Charon. |
| 13 June, 1983 |
Pioneer 10 crossed
the orbit boundary of Pluto. |
| 2115 |
Pluto will be
at maximum will be opposition distance from the Earth in the
year 2115. |
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