NCERT Book Class 6 Social Science (Geography) Chapter 1 The Earth in the Solar System

1
THE EARTH IN THE SOLAR SYSTEM

How wonderful it is to watch the sky after sunset! One Let’s Do
would first notice one or two bright dots shining in
You’ll need : 1 torch,
the sky. Soon you would see the number increasing. 1 sheet of plain
You cannot count them any more. The whole sky is paper, pencil and a
filled with tiny shining objects – some are bright, others needle.
dim. It seems as if the sky is studded with diamonds. Step :
They all appear to be twinkling. But if you look at 1. Place the torch in the centre
of the paper with its glass
them carefully you will notice that some of them do front touching the paper.
not twinkle as others do. They simply glow without 2. Now draw a circle around
any flicker just as the moon shines. the torch.
Along with these bright objects, you may also see 3. Perforate the paper with the
needle within the circled
the moon on most of the days. It may, however, appear
area.
at different times, in different shapes and at different 4. Now place the perforated
positions. You can see the full moon only once in about circle part of the paper on
a month’s time. It is Full moon night or Poornima. A the glass front and wrap the
fortnight later, you cannot see it at all. It is a New paper around the torch
with a rubber band.
moon night or Amavasya. On this day, you can watch
5. Take care that the switch
the night sky best, provided it is a clear night. of the torch is not covered.
Do you wonder why can’t we see the moon and all 6. In a dark room, stand at
those bright tiny objects during day time? It is because some distance facing a
the very bright light of the sun does not allow us to see plain wall. Switch off all
other lights. Now flash the
all these bright objects of the night sky.
torch light on the wall. You
The sun, the moon and all those objects shining in will see numerous dots of
the night sky are called celestial bodies. light on the wall, like stars
Some celestial bodies are very big and hot. They shine in the night.
are made up of gases. They have their own heat and 7. Switch on all the lights in
the room. All dots of light
light, which they emit in large amounts. These celestial
will be almost invisible.
bodies are called stars. The sun is a star. 8. You may now compare the
Countless twinkling stars in the night sky are situation with what happens
similar to the sun. But we do not feel their heat or to the bright objects of the
light, and they look so tiny because they are very very far night sky after the sun rises
from us. in the morning.