1. Answer the following questions briefly.
(a) How does a planet differ from a star?
Answer
Planet differs from star in the following manner:
• Planet does not have its own light while star emits their own light.
• Planet revolves around a star while star does not revolve around any celestial bodies.
• Planet does not twinkle while star does.
(b) What is meant by the ‘Solar System’?
Answer
The system formed by the sun, eight planets, satellites, asteroids and various other celestial bodies is called the Solar System.
(c) Name all the planets according to their distance from the sun.
Answer
Planets according to their distance from the sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
(d) Why is the Earth called a unique planet?
Answer
Earth is called a unique planet because this is the only planet where life exists. It has conditions for supporting life. 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.
(e) Why do we see only one side of the moon always?
Answer
The moon moves around the earth in about 27 days. It takes exactly the same time to complete one spin. Therefore, only one side of the moon is visible to us on the earth.
(f) What is the Universe?
Answer
The universe consists of billions of galaxies.
2. Tick the correct answer.
(a) The planet known as the “Earth’s Twin” is
(i) Jupiter
(ii) Saturn
(iii) Venus
► (iii) Venus
(b) Which is the third nearest planet to the sun ?
(i) Venus
(ii) Earth
(iii) Mercury
► (ii) Earth
(c) All the planets move around the sun in a
(i) Circular path
(ii) Rectangular path
(iii) Elongated path
► (i) Elongated path
(d) The Pole Star indicates the direction to the
(i) South
(ii) North
(iii) East
► (ii) North
(e) Asteroids are found between the orbits of
(i) Saturn and Jupiter
(ii) Mars and Jupiter
(iii) The Earth and Mars
► (ii) Mars and Jupiter
3. Fill in the blanks.
(a) A group of ________ forming various patterns is called a ________.
► stars, constellation
(b) A huge system of stars is called________.
► galaxy
(c) ________is the closest celestial body to our earth.
► The Moon
(d) ________is the third nearest planet to the sun.
► Earth
(e) Planets do not have their own________ and _________.
► heat, light