Our earth is an interesting place where we live. We see
high mountains, lush green valleys, deep oceans, sea, river, ponds, as well as
Our earth is one of the eight planets that revolve
around the sun in the solar system. Eight planets of the solar system are:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The largest
planet in the solar system is Jupiter, smallest planet is mercury, brightest
planet is Venus and coldest planet is Neptune.
Earth is the fifth-largest planet in the solar
system and the third-closest planet to the sun. Earth is about 150
million km away from the sun. It is just at right distance from the sun, have
liquid water and layer of air to sustain life.
the earth really round?
The earth seems to be flat to us and it is difficult to believe that earth
is sphere with a bulge at its equator and flattened at its top. Long back,
people believed that earth was flat that’s why they fear to sail far out to
sea, as they may fell off the edge of the earth! Then some sailor sailed around
the earth and came back to the same place from where they have started. Now it has
been seen by astronauts from the space that earth is round, flattened from the
top and swelled at the equator.
Rotation of the earth
Spin a bangle on any table top. Do you see any imaginary line in the
spinning bangle? This imaginary line that we see is called axis.
The earth also spins on its axis. This movement is called rotation.
The earth spins from west to east and complete its one rotation in approximately
24 hours. We don’t feel earth spinning because everything including us is
spinning along the earth at the same speed. It is the earth's rotation that causes
day and night.
do we have day and night?
Earth is always moving on its axis which allows sunlight
to shine on different parts of the earth. The area of the earth facing the
sun receives sunlight, experiences day and the area of the earth which does not
receive sunlight, experiences night. At all time, half portion of the earth
is lighted by the sun and half of the earth remains in darkness.
Let’s understand this with an activity.
Take a globe and fix it on table. Now light a torch
from front of the globe.
do you observe?
We can see that half portion of the globe is lit by the
torch represents day and the darker portion of the globe represents night.
we can say that the earth turns around like a top?
Place long stick in the ground in the sunlight. We can
see the shadow on the ground. Mark the shadow. Observe the shadow after of an
hour. We can see that this time size and direction of the shadow is different.
Repeat this observation for next 2 to 3 hour. We will find that the size and
direction of the shadow keeps on changing every hour. Change in shadow position
shows that the earth is constantly moving.
of the earth
As the earth rotates, it also moves around the sun in a
fixed path. This fixed path in which earth moves around the sun is called Orbit.
Movement of the earth around the sun in its fixed orbit is called revolution.
Earth takes one year to complete one revolution. Earth is slightly
tilted from its axis. Earth tilt’s and its movement around the sun in its fixed
path causes seasons.