30.
E. Answer the following questions in detail.
1. How is a planet different from a star?
2. Describe the third planet of the solar system.
3. What are the two types of movement shown by the planets? Describe.
4. What are the conditions that support life on earth?
5. What is the difference between a natural and a man-made satellite?
Think Deep and Respond
Answers
Answer:
1) Here are the reasons why a planet is different from a Star:
A planet( Example : Earth) has no light of its own whereas in a star( Example: Sun) we can see that it has light of its own.
A star is a ball of energy, but in case of planets , they are made up of different substances ; like clay , gravel, lava,etc.
2) The name of the third planet in the solar system is the Earth. It consists of humans, plants, animals, microorganisms,etc. In this planet , we can see that only 1/4th is land and remaining 3/4th is water.
3) The two types of movements are there namely rotation and revolution.
In rotation, the planet rotates on its axis.
In revolution, the planet revolves round a star .
4) The conditions which are needed to support life on Earth are
* It has atmosphere of its own .
* It has its own magnetic field which helps to deflect asteroids and meteoroids from coming to the Earth.
* It has water which is a vital element to support life.
* It is in such a position in the solar system where there is neither too hot nor too cold. Thus supporting the existence of life.
* It has its own natural satellite , the moon which also prevents the Earth from getting hit by asteroids and meteoroids.
These are some of the conditions needed to support life on Earth.
5) A natural satellite is formed by collision of planets or stars. Example : The moon
A man - made satellite is formed by humans in laboratories . Example : Sputnik.