Download The Solar System

The Solar System
The Planets
The Inner Planets
 Solar System = a group of objects in space that move around a
central star
 Planet = a large object that moves around a star
 Inner Planets
– Mercury (1st planet from the sun)
 Size of the Earth’s moon
 Covered with craters like the moon
 Gases present but not enough for an atmosphere
– Venus (2nd planet from the sun)
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Size of the Earth
Dry with an atmosphere that traps heat (887°F)
Atmosphere weighs 100 times Earth’s
Spins on its axis in the opposite direction of Earth
The Inner Planets
– Earth (3rd planet from the sun)
 Largest of the inner planets and has a moon
 The only planet with liquid water and can support life
 Reflects and absorbs just the right amount of sunlight to sustain life
– Mars (4th planet from the sun)
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Has two moons and the largest volcano in the solar system
Red planet because the soil is dark reddish brown
Has dust storms that last months
There is no liquid water now but scientists suspect there may have
been once because of the valleys and sedimentary rock.
The Outer Planets
 Outer planets
– Jupiter (largest planet – size of 3 Earths)
 Surrounded by a thin ring and at least 16 moons
 Atmosphere is active and has caused a 300 year hurricane (circular
storm)
– Saturn (known for its rings)
 Its rings are the widest and brightest
 Has at least 18 moons
– Uranus (7th planet from the sun)
 Has rings and at least 15 moons
 It is a giant blue-green ball of gas and liquid)
– Neptune (8th planet from the sun)
 Gas ball with circular storms like Jupiter
– Pluto (downgraded to a planetoid)
 Smallest and has a rocky surface
The Outer Planets
 Asteroids = orbits around the sun and are small
and rocky.
– Most asteroids travel between Mars and Jupiter in an
area known as the asteroid belt.
– Might be parts of planets that never formed
 Comets = small mass of dust and ice and orbits
and sun
– As it gets close to the sun, some ice melts and changes
to water vapor. It streams out in a long, glowing tail
Moons and Rings
 Moons
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All planets except Mercury and Venus have a moon
Moons are round and rocky
One of Jupiter’s moons has an active volcano
One of Saturn’s moons has a dense atmosphere that
causes it to glow red
 Rings
– Each gas planet (Saturn, Jupiter, Neptune) has rings
– Rings are tiny bits of dust, ice crystals, and small
pieces of rock