3.2   Text Questions :

Answer the following questions briefly :

1. How does a planet differ from a star?
Ans: Planets do not have their own light while stars emit their own light. Planets revolve round a star while stars do not revolve around any celestial bodies. Planets do not twinkle but stars do.

2. What is meant by ‘Solar System’ ?
Ans: The system formed by the sun, eight planets , satellites ,asteroids and other celestial bodies are called the solar system.

3. Name all the planets according to their distance from the sun.
Ans: The planets according to their distance from the sun are Mercury ,Venus ,Earth ,Mars , Jupiter , Saturn , Uranus , Neptune.

4. Why is the earth called a unique planet?
Ans: The earth is called a unique planet because this is the only planet where life exists. It has conditions for supporting life. It is neither too hot nor too cold. It has water and air which is needed for survival. There is oxygen in the air.

5. Why do we see only one side of the moon always ?
Ans: The moon moves round the earth in about 27 days. It takes exactly the same time to complete one spin. Therefore we see only one side of the moon always.

6. What is the universe?
Ans: Billions of galaxies together make the universe.

Tick the correct answers :

a) The planet known as the “ Earth’s Twin” is __________.
i) Jupiter                        ii) Saturn                           iii) Venus √

b) The third nearest planet to the sun is____________.
i) Venus                         ii) Earth √                             iii) Mercury

c) All the planets move around the sun in a ___________.
i) Circular path             ii) Rectangular path           iii) Elliptical path √

d) The pole star indicates the direction to the ___________.
i) South                        ii) North √                             iii) East

e) Asteroids are found because the orbits are  ___________.
i) Saturn and Jupiter               ii) Mars and Jupiter √                   iii) The Earth and Mars

Answer :
a) Venus                 b) Earth              c) Elliptical path             d) North                e) Mars and Jupiter

 Fill in the blanks:

i) On a ______ moon night we cannot see the moon.

ii) The sun is the ultimate source of _______ and _______ for the solar system.

iii) A group of ________forming various patterns is called a __________.

iv) A huge system of stars is called _________.

v)  __________ is the closest celestial body of our earth.

vi) _________ is the third nearest planet to the sun.

vii) Planets do not have their own _______and__________.

Answers :
i) New                    ii) Heat, light                  iii) Stars ,constellation                        iv) Galaxy
v) The moon        vi) The earth                   vii) Heat, light

What are the following :

a) Asteroids     –  Asteroids are tiny bodies that move round the sun.

b) Meteoroids –  Meteoroids are small pieces of rock which move around the sun.

c) Galaxy           –  Galaxy is a huge system of billion of stars and clouds of dust and gases.

d) The Sun       –  The Sun is in the centre of the solar system, It is huge and made up of extremely hot gases.