Solar System Class 4 Science

A. Which one is correct?

1. There are eight planets that revolve around the Sun.

Ans: b. eight

2. Mars is also known as the red planet.

Ans: a. red

3. Big Dipper is a group of seven stars.

Ans: b. seven

4. The Moon is the natural satellite of the Earth.

Ans: a. moon

5. Rotation causes day and night.

Ans: b. Rotation

B. Fill in the blanks:

1. A group of stars is called a constellation.

2. The Moon reflects the light of the Sun.

3. Earth completes one revolution in 365 days.

4. Moon is also called a satellite.

5. The fixed path taken by a planet to revolve around the Sun is called an orbit.

C. Write ‘T’ for true or ‘F’ for false:

1. The Sun is the centre of the solar system. T

2. Venus is the planet closest to the Sun. F

3. Jupiter is the smallest planet in our solar system. F

4. Saturn has a magnificent set of large gleaming rings. T

D. Match the columns:

1. Equator — c. hemispheres

2. Satellite — d. moon

3. North Star — a. direction

4. Rotation — e. day and night

5. Axis — f. imaginary line on which the Earth rotates

6. Sun and eight planets — b. solar system

E. Answer the following questions:

1. Only planet Earth has life on it. Why?

Ans:

Earth has air, water, suitable temperature and land, which support life.

2. Why does the Sun look so big and the other stars look so small?

Ans:

The Sun looks big because it is very close to the Earth, while other stars are very far away.

3. Why don’t you feel hot when you stand outside in moonlight?

Ans:

Because the Moon does not have its own heat; it only reflects the light of the Sun.

4. Write the differences between:

a. Inner planets and outer planets

Ans:

Inner planets: Mercury, Venus, Earth, Mars (close to the Sun)

Outer planets: Jupiter, Saturn, Uranus, Neptune (far from the Sun)

b. Rotation and revolution

Ans:

Rotation: Movement of Earth on its axis (causes day and night)

Revolution: Movement of Earth around the Sun (causes year)

c. Axis and equator

Axis: An imaginary line on which the Earth rotates

Equator: An imaginary line that divides the Earth into two hemispheres