Download Rotation and Revolution of the Earth-PPT

Our Moving Planet
Revolution and Rotation
All of the planets in our solar system orbit, or
revolve, around the Sun. Scientists
pretend that planets and stars have a line
drawn through their middles. This line is
called an axis. Our sun spins around its
axis just like each planet does. Spinning
on an axis is called rotation.
Earth rotates on an imaginary line
called an axis. The North Pole is
at one end of the axis. The South
Pole is at the other end. Earth’s
axis is tilted, not straight up and
down.
Day
Night
Sun
This is a globe. The stick through
its middle is its axis. The globe
spins around its axis. Planets
don't have sticks through their
middles. A planet's axis is an
imaginary, or made-up line
through its middle.
Earth rotates, or turns one complete time around the axis,
once each 24 hours. We call this rotation day and night.
Every day, the Sun appears to come up
and go down. However, the Sun does
not move past Earth. Instead, Earth
turns, or rotates. As Earth rotates,
different parts of Earth move through
the Sun’s light and then out of the
light. This causes day and night. One
complete rotation takes 24 hours.
This is a model of the sun’s light as
it strikes the earth.
Earth also revolves, or moves in a circular path
around the Sun. The path that Earth follows
around the Sun is its orbit. It takes 365 ¼
days for Earth to travel around the Sun.
One complete revolution is 365 ¼ days.
The Earth revolves around the Sun once a
year. To revolve means to move its
position around the Sun. Rotating is
turning on an axis, revolving is moving
around the Sun. The Earth makes one
complete rotation every 24 hours. The
Earth is both rotating and revolving all the
time.
Because Earth’s axis is tilted, the North Pole and South Pole usually
do not receive the same amount of sunlight at the same time. This
causes the seasons. When the North Pole is tilted toward the Sun,
the Sun’s rays strike that part of Earth directly. When this happens, it
is summer in the northern part of Earth. When the North Pole is tilted
away from the Sun, the Sun’s rays do not strike that part of Earth as
directly. When this happens, it is winter in the northern part of Earth.
In summer, your part of Earth is tilted toward the Sun. This makes
the Sun appear high in the sky. In winter, the Sun appears lower in the
sky.
North American
Summer
Winter
Revolution and Rotation
Earth revolves once a year around the Sun.
Earth rotates once every 24 hours on its axis.
rotation
revolution
Earth is both rotating and
revolving all the time.
Shadows show us that the Earth is
changing positions.