1. Answer the following questions briefly.

(a) How does a planet differ from a star?
Answer– A planet differs from a star because the stars have their own heat and light whereas the planets do have not their own heat and light. They receive heat and light from the stars.

(b) What is meant by the ‘Solar System’?
Answer– The sun, the eight planets, satellites, and some other celestial bodies known as asteroids and meteoroids form the solar system. We often call it the solar family, with the sun as its Head.

(c) Name all the planets according to their distance from the sun.
Answer– The planets according to their distance from the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

(d) Why is the Earth called a unique planet?
Answer– Conditions favorable to support life are probably found only on the earth. The earth is neither too hot nor too cold. It has water and air, which are very essential for our survival. The air has life-supporting gases like oxygen. Because of these reasons, the earth is a unique planet.

(e) Why do we see only one side of the moon always?
Answer– The moon moves around the earth in about 27 days and it takes almost the same time to rotate about its axis. Therefore, only one side of the moon is visible to us on the earth.

(f) What is the universe?
Answer– Millions of galaxies together form a universe. It is difficult to imagine how big the universe is. Scientists are still trying to find out more and more about it.

2. Tick the correct answer.

(a) The planet known as the “Earth’s Twin” is
(i) Jupiter (ii) Saturn (iii) Venus
Answer: (iii) Venus

(b) Which is the third nearest planet to the sun?
(i) Venus (ii) Earth (iii) Mercury
Answer: (ii) Earth

(c) All the planets move around the sun in a
(i) Circular path (ii) Rectangular path (iii) Elongated path
Answer: (iii) Elongated path

(d) The Pole Star indicates the direction to the
(i) South (ii) North (iii) East
Answer: (ii) North

(e) Asteroids are found between the orbits of
(i) Saturn and Jupiter (ii) Mars and Jupiter (iii) The Earth and Mars
Answer: (ii) Mars and Jupiter

3. Fill in the blanks:

(a) A group of _____________ forming various patterns is called a _____________ .
Answer: A group of stars forming various patterns is called a constellation.

(b) A huge system of stars is called____________.
Answer: A huge system of stars is called a galaxy.

(c) ____________ is the closest celestial body to our earth.
Answer: Moon is the closest celestial body to our earth.

(d) ___________is the third nearest planet to the sun.
Answer: Earth is the third nearest planet to the sun.

(e) Planets do not have their own____________ and ____________.
Answer: Planets do not have their own light and heat.