7. Learning Objectives
After completing this chapter students may be able to:-
Explain the concepts of:-
• The shape of the Earth
• The Earth’s
movements and its effect.
• locate the position of
the Earth in space.
• define key terms such
as orbit, axis, equator,
and hemisphere.
9. Where does the planet Earth was
according to the people in old
times?
Most of the people in old times
believed that the Earth was at the
centre of the Universe.
• The sun and other planets moved
around the Earth.
10. COMMUNICATIONS ANTENNAS
On-board the Hubble telescope are two identical
S-Band transmitters. In 1998 one of the transmitters
failed, however the secondary transmitter has kept
up with the extra load by rotating the telescope to
maintain communication. The radio waves
converted from the solid-state recording system are
sent to a NASA communication satellite, which in-
turn relays the information to Earth.
• Can you tell the
name of the thing
shown in this
picture?
Satellite.
11. •Orbit:-
The orbit is
the name of the
path on which
Earth or any other
planet revolves
around sun.
Earth & its Movements
12.
13. What is the movement of Earth around sun
called?
Revolution
What is the name of imaginary line that joins
the North and South Pole through the center of
the Earth ?
Axis
14. Effects of Rotation and Revolution
•Rotation cause day and night.
•Revolution Cause different
seasons.
Tell the names of the seasons?
Summer, winter, autumn, spring.
15.
16. • What divides the Earth into northern
and southern hemisphere?
Equator
• What causes day and night?
Rotation
• What is the shape of the Earth?
A Sphere
17. APERTURE DOOR
• The adaptive optics on the Hubble telescope allow it to conduct high-
resolution optical visualization over a wide field of view. The aperture
door itself can be closed if needed, to prevent light from external
sources from entering the telescope.
