Solar System and Inner and Outer Planets

The Solar System, Inner

and Outer Planets

What is the Solar
System?

The solar system is about
4.5 billion years old and is
made up of the sun, the
eight planets and their
moons, dwarf planets, and
countless asteroids,
comets, and other small,
icy objects. However, even
with all these things, most
of the solar system is
empty space.

Multiple Choice

About how old is the solar system?

• 4.5 billion years old

• 3.9 million years old

• 2 million years old

• 5 million years old

The Sun

The sun is the largest object
in our solar system. It is
made of hydrogen and
helium gasses and is
extremely hot. The sun is
constantly changing the
hydrogen in it’s core into
helium and this process
gives off large amounts of
radiation, or energy. Life on
earth depends on this energy
in the form of light and heat.

Multiple Choice

Which word goes in this blank?

The sun is the ______object in our solar system.

• smallest

• prettiest

• coldest

• largest

The Planets

After the sun, the largest
objects in the solar system
are the planets. There are 8
planets. Mercury is the
closest to the sun. Then
comes Venus, Earth, Mars,
Jupiter, Saturn, Uranus and
Neptune.

Most planets have at least
one moon that orbits it.
Some planets have more
than one moon.

Multiple Choice

How many planets are there?

• 7

• 9

• 6

• 8

Multiple Choice

Which planet is closest to the sun?

• Venus

• Mercury

• Earth

• Jupiter

Pluto

Pluto used to be
called the smallest
planet in the solar
system. However, in
2006 scientists
decided to call Pluto a
dwarf planet because
it is so small.

Multiple Choice

Is pluto still classified as a planet?

• Yes, it is the smallest planet.

• No, It is a dwarf planet because it was too small to be a planet.

Terrestrial Planets

Scientists divide the planets
into two groups: The Terrestrial
Planets and The Jovian
Planets.

The Terrestrial Planets are
Mercury, Venus, Earth and
Mars. These planets are closer
to the sun and smaller than
most of the outer planets.
Terrestrial planets are alike
because they all have hard,
rocky surfaces and share a
number of other similar
qualities.

Multiple Choice

Which planets are the terrestrial planets?

• Mercury, Earth, Venus, Mars

• Jupiter, Saturn, Uranus, Neptune

Multiple Choice

What makes the terrestrial planets similar?

• They are all hot

• They are all cold

• They are all rocky planets

• They are all colorful planets

Jovian Planets

Jupiter, Saturn, Uranus and
Neptune are the Jovian Planets.
They are farther away from the
sun than the terrestrial planets
and are much larger than the
terrestrial planets.

The Jovian planets are made of
gasses and are often called the
‘Gas Giants’. They also have
many moons, unlike the
Terrestrial planets which have
only one moon, two moons or no
moons at all.

Multiple Choice

The Jovian planets are also called the..?

• Fancy Planets

• Gas Giants

• Big Planets

• Cold Planets

Multiple Choice

About how old is the solar system?

• 4.5 billion years old

• 3.9 million years old

• 2 million years old

• 5 million years old

Multiple Choice

Which word goes in this blank?

The sun is the ______object in our solar system.

• smallest

• prettiest

• coldest

• largest

Multiple Choice

How many planets are there?

• 7

• 9

• 6

• 8

Multiple Choice

Which planet is closest to the sun?

• Venus

• Mercury

• Earth

• Jupiter

Multiple Choice

Is pluto still classified as a planet?

• Yes, it is the smallest planet.

• No, It is a dwarf planet because it was too small to be a planet.

Multiple Choice

What makes the terrestrial planets similar?

• They are all hot

• They are all cold

• They are all rocky planets

• They are all colorful planets

Multiple Choice

Which planets are the terrestrial planets?

• Mercury, Earth, Venus, Mars

• Jupiter, Saturn, Uranus, Neptune

Multiple Choice

The Jovian planets are also called the..?

• Fancy Planets

• Gas Giants

• Big Planets

• Cold Planets