The Outer Planets
**Between the inner and outer planets, there is a region called the astroid belt. The astroid belt is a region that
contains large, swarming rocks.
The Outer planets: mostly made of hydrogen and helium, have several moons, have an liquid outer structure, and
contain rocky cores.
Planet
Jupiter
Dimensions
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772,800,000 km from the sun
Mass is 318 times more than
Earth
Revolution: 11.9 years
Rotation: 9.9 hours
Diameter: 142,980 km
Temperature:
Key Facts
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Largest planet
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Has at least 60 moons
Io: has active volcanoes
Europa: has ice and possibly an ocean
Ganymede: largest moon in the solar system ( larger than Mercury)
Callisto: salty ocean (?)
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Jupiter's outer atmosphere is very cold; however, inside the planet,
it gets hotter and hotter closer to the center.
-166°F to 126°F
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Composed of Hydrogen and Helium
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Great Red Spot: giant storm that has existed since the 17th century
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Jupiter takes about 12 years to orbit the sun and rotates in about 10
hours.
NASA Research:
1973 Pioneer Missions- images of moons and Jupiter's atmosphere
1979 Voyager Missions- discovered earth's rings
NASA wants to study Jupiter's ice moons and launch Juno by 2011.
Saturn
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1,427,000,000 km from Sun
Stats
revolution – 29.5 years
rotation – 10.2 hours
diameter – 120,540 km [ about 9.5 times
the earth]
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Has at least 23 moons and a
spectacular ring system
Titan- has own atmosphere; 2nd
largest moon in solar system
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Named after the Roman god, Saturnus ( father of Zeus)
The tilt of Saturn's axis causes the sun to heat the planet's northern
and southern halves unequally, resulting in seasons and
temperature changes. Each season lasts about 7 1/2 Earth years,
because Saturn takes about 29 times as long to go around the sun
as Earth does.
Atmosphere: Hydrogen and Helium
First rings discovered by Galileo
Visible with telescope
Around 1980, scientist discovered "spokes" on rings
NASA Research
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Temperature: averages -285° F
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2,870,000,000 km from Sun
Stats
revolution – 84 years
rotation – 17 hours retrograde
diameter – 51,120 km
• over four times Earth’s
15 moons and rings
Average temperature of -221 degrees C
above cloud tops
Uranus
The clouds that circle the planet are
greenish blue.
Neptune
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Voyager I ( 1980) : close up images of the planet
Voyager II ( 1981): close up images of the moon
Cassini-Huygens ( 2004): images of lakes, coastlines,
mountains; discovered lightning that is 1000 times more
powerful than Earth's lightning
Cassini Probe ( 2006): geysers; hurricane discovered at South
Pole
Discovered in 1781
Over twice Saturn's distance from the Sun
Mass = 15 Earths
Hydrogen, helium and methane atmosphere
"Ice giant"
Named after the Greek god of the sky
Axial tilt of 97.77 degrees- seasonal changes very dramatic
NASA Research:
Voyager 2 ( 1986)- studied atmosphere and unique weather
No other current missions planned.
Size: About 4 Earths across
Number of moons: 8
T temperature: -353 F. So Neptune is
SUPE R cold!
Named for the Roman god of the Sea
Stats:
revolution – 164.8 years
rotation – 16 hours
diameter – 49,530 km
• about 4 times the size of Earth
13 known moons
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Triton- largest moon
Discovered in 1846 by a mathematician, although Galileo observed Neptune
in 1612
Neptune's atmosphere is notable for its active and visible weather patterns.
Winds have been recorded up to 2100 km/h
Axial tilt is 28 degrees
The planet is surrounded by blue clouds
and dark rings caused by methane gas.
Other items:
Pluto – 5,900,000,000 km from Sun
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discovered in 1930
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orbit crosses Neptune’s and is tilted 17o
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so cold (-230oC) that most gasses freeze
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diameter – 2300 km
Eris – over 10,000,000,000 km from Sun
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discovered in 2003
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larger and more massive than Pluto
Ceres – 414,000,000 km from Sun
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discovered in 1801 – originally considered a planet
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part of the Asteroid Belt
NASA Research:
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Voyager 2 ( 1989): ring system studied; noticed " Great Dark Spot" (
evidence of turbulent wind)
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No current missions planned.