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Jupiter
Jupiter is the largest planet in the Solar System. It weighs as much
as 318 whole Earths (twice the mass of all the other planets combined!).
Like most planets, Jupiter is a naked-eye object, known since antiquity.
Galileo used a telescope to discover moons of planets. It is made
of gasses and ices with a little rock and is believed to have a solid
core surrounded by liquid metallic hydrogen. This liquid metal gives the
planet its magnetic field. Despite its distance from the Sun, Jupiter
radiates more heat than it receives, a fact attributable to the huge mass
of the planet and the movements of its gasses.
Jupiters most notable features are its giant red spot and its overall
colors. The Great Red Spot is a huge spinning mass of gas which rotates
slowly round the planets Southern Hemisphere. It is the size of
2 Earths. The belts and bands of color are caused by varying winds pushing
gasses containing different allotropes of sulfur across the atmosphere.
Not long ago it was believed that Jupiter had no rings, but recently
a thin system of rings has been discovered around the planet. Jupiters
rings are believed to be made of small rocks and dust but, unlike other
ring systems, they contain no ice.
In 1994 Jupiter was hit by the fragments of the Shoemaker-Levy 9 comet
which exploded into its Southern Hemisphere. The blemishes from this are
still visible. It is events like this which replenish the dust and matter
in Jupiters ring.
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Diameter
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143, 000 km |
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Mass
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1.9 × 1027kg |
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Mean Distance from sun
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778,330,000 km |
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Mean Density
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1.33 g/cm3 |
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Rotational Period
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0.4 Earth days |
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Orbital Period
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4333 Earth days |
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Mean Orbital Velocity
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13 km/s |
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Atmosphere
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90% Hydrogen, 10% Helium |
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Average Surface Temperature
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-121°C |
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Equatorial Surface Gravity
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22.88 m/s2 |
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