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The Planets
Chapter 7 Lesson 3
Page 340
What makes up the solar
system?
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A solar system is
made of a star and
the objects that orbit
around it
A planet is a large
object that orbits a
star
A moon is a natural
object that orbits a
planet
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All but two planets in
our solar system have
one or more moons
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From nearest to
furthest from the sunMercury, Venus,
Earth, Mars, Jupiter,
Saturn, Uranus, and
Neptune (My Very
Educated Mother Just
Served Us Nachos!)
Different types of
small objects are
present in space:
comets, asteroids,
and meteors.
What makes up the solar
system? (continued)
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A comet is a mixture
of frozen gases, ice,
dust, and rock that
moves in an elliptical
orbit around the Sun.
An asteroid is a rock
that revolves around
the Sun
Meteoroids are small
objects in space. If
they enter into
Earth’s atmosphere
they are called
meteors.
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What are the inner planets?
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The inner planets
are:
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Mercury, Venus,
Earth, and Mars
Closer to the sun
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They share common
characteristics:
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They all have surfaces
made of rock
They are known as the
terrestrial planets
These planets have few
or no moons
None of them have
rings
What are the inner planets?
(Continued)
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Mercury is the closest
planet to the sun, and
its surface looks a lot
like the Moon’s
surface
Venus has a surface
that shows evidence
of violent volcanic
activity.
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Earth is the largest
inner planet and is
the only planet in the
solar system known
to support life
Mars is known as the
red planet because it
has a reddish surface
color
What are the outer planets?

The outer planets are
 Jupiter, Saturn,
Uranus, and Neptune
 The four planets
beyond the asteroid
belt
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They have some
similarities
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Made mostly of gas
They have a metallic
core and a thick
atmosphere
They are much larger
than the inner planets
All have rings and
many moons
A day on an outer
planet is very short;
they spin very rapidly
on their axes
What are the outer planets?
(Continued)
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Jupiter is distinct
because of The Great
Red Spot which is a
storm that has been
blowing for more than
400 years.
Saturn is known for
its large, bright rings.
The rings are made of
pieces of ice and rock
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Uranus has a
distinctive blue-green
color due to the
methane in the
planet’s upper
atmosphere
Neptune has the
strongest winds of
any planet and
appears blue.
Dwarf Planets

Pluto was once known as the ninth
planet. In 2006, the International
Astronomical Union officially
reclassified Pluto as a dwarf planet
How do the moons
compare?
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Different planets have
different numbers and
sizes of moons
The inner planets
have fewer moons
than the outer planets
Mercury and Venus
have no moons;
Jupiter and Saturn
have at least 60
moons

Moons are also called
satellites
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A satellite is an object
in space that circles
around another object
Humans have created
artificial satellites that
include weather and
communication
satellites
How do we explore the
solar system?
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Exploration of other
worlds started in
1959 when a Soviet
rocket carrying
scientific instruments
landed on the moon.
Space Probes are
vehicles carrying
instruments that are
sent to explore
objects in space
Quick Facts
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The 4 inner planets
are made of rock, and
few moons
The 4 outer planets
are made of gas, with
many moons
The closer to the sun,
the shorter the orbit
The further from the
sun, the longer the
orbit
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The outer planets
spin faster on their
axes, therefore,
they have shorter
days