Our Earth
Our Earth
Our Earth - QuestionsPage
Our Earth
Our earth is an interesting place where we live. We see
high mountains, lush green valleys, deep oceans, sea,
river, ponds, as well as vast desert.
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.
Is 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.
Why 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.
What 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.
How 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.
Revolution 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.
