Our solar system consists of nine planets. The Earth is the third planet from the Sun. The Earth is always rotating on its axis from the west to the east. An axis is an imaginary line that connects the North and South Poles. It takes 24 hours or one day to complete one rotation. The Earth also moves around the Sun at the same time.It revolves around the Sun in 365 ¼ days or one year.
The Moon is called a natural satellite of the Earth. The Moon rotates on its axis. It takes about 28 days to complete one rotation. At the same time,it also moves round the Earth. It takes about 28 days to complete one movement. The Earth moves around the Sun and the Moon moves round the Earth simultaneously.
The sumlight travels in a straight line. It cannot go around things. That is why there there are dark shadows behind objects that stand in its way.In early morning and evening, the Sun rises on the horizon and makes long shadows. At noon, the Sun is directly overhead and makes short shadows. When the Earth rotates eastward, the Sun looks as though it is moving to the west. The rotation of the Earth on its axis from the west to the east changes the length and the position of the shadow thoughtout the day.
Lesson 1: They Move!
