Page 72 - Science class 4

ROLE OF THE SUN

The sun plays a major role in causing changes in
weather conditions :

± We all know that the Earth moves around the

sun. This movement is called revolution . The

Earth is tilted on its axis at such an angle that
one half of the Earth facing the sun has longer
Summer
and hotter days which is called summer

season. The other half of the Earth which is
away from the Sun has cooler and shorter

days and is called winter season . The Earth

also moves on its own axis. This movement is

called rotation .
Revolution causes changes in season, while

rotation causes day and night. Winter

Movement of the Eart around the Sun

± The Sun’s heat also causes winds to blow.

When the air gets heated up due to heat
of the Sun, it becomes lighter. The warm

air rises up. Cool air (which is heavier)
then comes in to take its place. This

movement of air causes winds. The Sun
has the ability to change the condition of

Revolution water which causes humidity and rain.