3rd Class Science Earth, Moon and Sun Notes - The Earth and The Moon

The Earth and the Moon

1. We all live on the Earth. Earth is a big, round and slightly flattened at the poles. Our Earth consists of three things: land, water and air.

2. During eclipse, Earth casts round shadow on the Moon. If we observe ship sailing away from us, the hull disappears first, then the top of the mast. These two things tell us that the Earth is round in shape.

3. There are nine planets revolving around the sun in the order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Planets do not glow on their own but stars like sun glow. The Earth is about 150 million kilometres away from the Sun.

4. The Earth has two types of movements: rotation and revolution.

5. The Earth spins around itself on an axis. This motion around its own axis is called the rotation of the earth. The Earth completes one rotation in 24 hours. It spins from west to east.

6. The rotation of Earth produces day and night. The part of the Earth which faces the Sun and gets light has a day while the other half of the Earth which is away from the Sun and does not get the light has a night.

7. The Earth rotates around the Sun in 365. days. This motion is called revolution. The revolution of earth gives rise to different seasons.

8. Sun is a big ball of burning gases which is very hot. Sun looks small because it is 150 million kilometres away from us but actually it is very very bigger than the Earth. All planets revolve around sun.

9. Moon is a natural satellite of the Earth. It is smaller than the Earth and takes about 28 days to complete one revolution around the Earth. It is about 384,400 km away from us. It has no light of its own but reflects the light of the Sun.

10. We see different shapes of the Moon. When we See the complete Moon like a round ball we call it full moon. The full moon day is called purnima. When we do not see the lighted face of the Moon, it is the new moon. The new moon day is called amavasya. When it is a crescent moon we see only a part of its lighted face.

11. It is a full moon when the Earth lies between the Sun and the Moon. It is a new Moon when the Moon lies between the Sun and the Earth.

12. Stars are big heavenly objects which can emit heat and light on their own. Some stars occur in groups and interesting shapes. Such groups are called constellations.