Content: 1. The solar system.
2. Rotation, evolution of the earth and moon.
3. The place beyond the atmosphere which is extremely large is called space.
Sub-Topic 1: The Solar System
The planet earth, on which we live, is moving through space all the time. It is going round the sun. In doing this it carries us all through space. The earth travels through the space but we do not realize this because the air around the earth is carried along with it. The sun together with all the bodies which revolves round it makes up the solar system. The solar system consists of the sun, nine planets, 32 moons which revolve round some of the planets, many comets and asteroids.
The planets are:
- Define the solar system?
- List the nine planets.
Sub-topic 2: Rotation, evolution of the earth and moon.
Rotation of the Earth:
The earth rotates about an axis through the north and south poles. As the earth rotates different parts of its surface come into the light from the sun. The area that
is receiving light from the sun has day, and that which is away from the sun has night. The time it takes to rotate round its own axis is one day (24 hours).
Rotation of the Moon:
The moon is a satellite of the earth and revolves round it once in about 29 days. Five phases occur during the rotation of the moon. They are as follows:
- New moon
- Quarter moon
- Half moon
- Three quarter moon
- Full moon.