Chapter 1 – The Earth in the Solar System

Page No 7:

Question 1:

Answer the following questions briefly.

(a) How does a planet differ from a star?

(b) What is meant by the ‘Solar System’?

(c) Name all the planets according to their distance from the Sun.

(d) Why is the Earth called a unique planet?

(e) Why do we see only one side of the Moon always?

(f) What is the Universe?

Answer:

(a) Stars are big and hot celestial bodies made up of gases. They have their own heat and light, which they emit in large amounts. Planets are also celestial bodies, but they do not have their own heat and light. They are lit by the light of stars.

(b) The Sun, eight planets, satellites and some other celestial bodies known as asteroids and meteoroids form the solar system.

(c) In order of their distance from the sun, the eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

(d) Conditions favourable to support life are probably present only on 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 in the solar system.

(e) The Moon moves around the Earth in about 27 days. It takes exactly the same time to complete one spin. As a result, only one side of the Moon is visible to us on the Earth.

(f) A galaxy is a huge system of billions of stars, and clouds of dust and gases. Millions of such galaxies make up the universe.

Question 2:

Tick the correct answers.

(a) The planet known as the “Earth’s Twin” is

(i) Jupiter

(ii) Saturn

(iii) Venus

(b) Which is the third nearest planet to the Sun?

(i) Venus

(ii) Earth

(iii) Mercury

(c) All the planets move around the Sun in a

(i) Circular path

(ii) Rectangular path

(iii) Elongated path

(d) The Pole Star indicates the direction to the

(i) South

(ii) North

(iii) East

(e) Asteroids are found between the orbits of

(i) Saturn and Jupiter

(ii) Mars and Jupiter

(iii) The Earth and Mars

Answer:

(a) The planet known as the “Earth’s Twin” is

(i) Jupiter

(ii) Saturn

(iii) Venus

(b) Which is the third nearest planet to the Sun?

(i) Venus

(ii) Earth

(iii) Mercury

(c) All the planets move around the Sun in a

(i) Circular path

(ii) Rectangular path

(iii) Elongated path

(d) The Pole Star indicates the direction to the

(i) South

(ii) North

(iii) East

(e) Asteroids are found between the orbits of

(i) Saturn and Jupiter

(ii) Mars and Jupiter

(iii) The Earth and Mars

Page No 8:

Question 3:

Fill in the blanks.

(a) A group of ________ forming various patterns is called a ________.

(b) A huge system of stars is called _________.

(c) ________ is the closest celestial body to our Earth.

(d) ________ is the third nearest planet to the Sun.

(e) Planets do not have their own _________ and __________.

Answer:

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

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

(c) The Moon is the closest celestial body to our Earth.

(d) Earth is the third nearest planet to the Sun.

(e) Planets do not have their own heat and light.

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