The Solar System
 Our solar neighbourhood is an exciting
place. The Solar System is full of planets,
moons, asteroids, comets, minor planets,
and many other exciting objects.
 Everything in the Solar System orbits or
revolves around the Sun. The Sun contains
around 98% of all the material in the Solar
System. The larger an object is, the more
gravity it has. Because the Sun is so large,
its powerful gravity attracts all the other
objects in the Solar System towards it.
The Sun
The Sun is at the center of
the Solar System.
The Sun is a star: a shining
ball in space.
A star is made of very hot gas.
It produces light and energy.
There are eight planets in our Solar
System.
What is a planet?
A planet is
a large ball
of rock or gas
in space.
The Sun’s Family
The Sun’s Family
The Solar System also
includes:
 The moons of some planets: celestial
bodies who travel around a planet;
 The Asteroid Belt:
rocks in space
between Mars and Jupiter.
 Pluto: the dwarf planet; it isn’t a
planet because it’s too small.
Planets
Planets are cold
and get light from the Sun.
Terrestrial Planets (Closest to the Sun)
The four terrestrial planets are
rocky and dense.
They are:
MERCURY
VENUS
EARTH
MARS
Mercury is the closest planet to the
Sun and the smallest planet.
Venus is
the second closest
Planet to the Sun.
It’s the hottest planet.
It is the only place
in the universe
where life is
known to exist.
The Earth travels around the Sun.
Earth is the third planet from the Sun.
Mars is called the
‚red planet‛
for the colour
of its rocks.
Asteroid Belt
Asteroids are rocks in the space
between Mars and Jupiter.
The Jovian planets (gas giants)
The outer region of the Solar
System is home to the gas giants.
JUPITER
SATURN
NEPTUNE
URANUS
Jupiter is the largest planet in
Solar System.
Saturn
has an extensive
ring system.
Uranus has
27 known
Satellites (moons).
Neptune is
blue.
It is the
Furthest planet
Away from the Sun.
Pluto is not a planet,
it’s too small.
It’s very far from the Sun, and
very cold.
The Moon
is Earth’s
only natural
satellite.
The Moon moves around the Earth.
Many planets have moons, but not
all of them.
Ice (frozen water) can be
found on some planets,
but only the ones which
have an atmosphere.
Mercury, for example, is
very hot and has no
atmosphere.
Dwarf Planets
Dwarf planets are spherical
bodies that orbit the Sun.
They are smaller than
planets. The most well
known dwarf planet is
Pluto, that until now was
considered a planet.
Small Bodies of the Solar
System
In this group, tens of
thousands of asteroids and
comets are included.
Asteroids
Asteroids are small bodies
of an irregular form that
orbit the sun. They are all
found in 2 regions: the
Asteroid belt between Mars
and Jupiter, and the Kuiper
belt past Neptune.
Comets
Comets are ice stars that
orbit the Sun, with very
elongated elliptic orbit.
When they get closer to the
Sun, they show a ‘shining
tail’. These are called
Shooting Stars’
The most well known comet is
the ‘Halley’.
Occasionally, an asteroid or a
comet will hit a planet. This
can have serious consequences.
Scientists believe that a crash
of this type caused the
extinction of dinosaurs 65
million years ago.
When small planets (like
grains of dust or sand)
reach the Earth, and start to
collide with the
atmosphere, they become a
shooting star.
The ones that arrive
without burning out are
called meteoroids.