Page 101 - Social Studies 4

Lesson 3 oriGin oF tHe eartH Unit 5

Objectives:

On completion of this lesson, students will be able to:
• Explain basic idea about the origin of universe and the earth.
• Identify the planets from the solar system.

The earth is about 4.54 billion years old.

Many of the scientists agree with the ‘Big Bang Theory’ where an expansion
of space occurs. As a result, the universe was formed about 13.8 billion
years ago. The solar system in which, the sun, the moon, and the planets
were formed about 4.54 billion years ago. Including the solar system, our
beautiful planet the earth is also a part of the universe.

The sun was made first through compression of materials (hydrogen
75%, helium 24% and oxygen, carbon, gold, silicon, uranium water
vapor, etc. 1% by mass by its own gravity and grew bigger. The sun
attractes the surrounding materials because of its gravity. But, those
materials around the sun that didn’t fall into the sun became different
planets. The moon was made from the same materials and the same
process. The Moon revolves round the Earth. So, it is called a ‘satellite’.

Megha's Integrated Social Studies - 4 97