1. The Earth in the Solar System (Universe and Earth)

How wonderful it is to watch the sky after sunset! One would first notice one or two bright dots shining in the sky. Soon you would see the number increasing. You cannot count them any more. The whole sky is filled with tiny shining objects – some are bright, others dim. It seems as if the sky is studded with diamonds. They all appear to be twinkling. But if you look at them carefully you will notice that some of them do not twinkle as others do. They simply glow without any flicker just as the moon shines. 

Full Moon and New Moon

Along with these bright objects, you may also see the moon on most of the days. It may, however, appear at different times, in different shapes and at different positions. You can see the full moon only oncein about a month’s time. It is Full moon night orPoornima. A fortnight later, you cannot see it at all. It is a New moon night or Amavasya. On this day, you can watch the night sky best, provided it is a clear night. ❓Different Phases of the Moon 

Do you wonder why can’t we see the moon and all those bright tiny objects during day time? It is because the very bright light of the sun does not allow us to see all these bright objects of the night sky. 

The sun, the moon and all those objects shining in the night sky are called celestial bodies. 

Stars and Constellations

Some celestial bodies are very big and hot. They are made up of gases. They have their own heat and light, which they emit in large amounts. These celestial bodies are called stars. The sun is a star. 

Countless twinkling stars in the night sky are similar to the sun. But we do not feel their heat or light, and they look so tiny because they are very very far from us.