Earth in the Solar System | CBSE | NCERT

1. EARTH IN SOLAR SYSTEM

2. CELESTIAL BODIES
 The sun, moon, stars and planets and all those objects
shining in the night are called celestial bodies.
 Some celestial bodies are very big and hot. They are
made of gas, have their own heat and light. They emit
in large amounts. These celestial bodies are called stars.
The sun is a star.
 While watching the night sky, we notice various
patterns formed by different groups of stars. These are
called constellations. Ursa Major is one such
constellation.

4.  In ancient times, people used to determine directions
during the night with the help of stars. The North star
indicates the north direction. It is also called pole star.
 Some celestial bodies do not have their own heat and
light. They are lit by the light of the stars. Such bodies
are called planets.

5. THINK AND SHARE
 Think: Why ursa major is so important?
 Share: Share your thoughts in the class

6. PEER INSTRUCTIONS
 The following is (are) example(s) of celestial body
(ies).
1. Sun
2. Moon
3. Stars
4. Asteroids
a. 1 and 4
b. 2 and 3
c. 1 2 and 3
d. 1 2 3 and 4

7. The different group of stars is known as
a) Constellations
b) Celestial bodies
c) Asteroids
d) Comet
Dicky has lost her direction, so she can identify the
direction by looking at
1. Moon
2. Pole star
3. Ursa major
a. 1 and 3
b. 2 and 3
c. Only 2
d. Only 3

8. The ‘Pole star’ is
a) North star
b) South star
c) East star
d) West star
Pole star is a part of ursa major
True
False

9. THE SOLAR SYSTEM
‘Sol’ in Roman mythology is the ‘Sungod’. ‘Solar’ means
‘related to the sun’. The family of the sun is, therefore,
called the solar system. The sun, eight planets, satellites
and some other celestial bodies known as asteroids and
meteoroids form the solar system.
The Sun:
(i) The sun is the centre of solar system.
(ii) It is huge and made up of extremely hot gases. The
pulling force of the sun binds the entire solar system.
(iii) The sun is the ultimate source of heat and light for the
solar system.

11. PLANETS
(i) The word ‘planet’ comes from the Greek word ‘Planetai’ which
means wanderers.
(ii) There are eight planets in our solar system-Mercury, Venus,
Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
(iii) All the eight planets of the solar system move around the
sun in fixed paths. These paths are elongated. They are called
orbits.
(iv) Mercury is the nearst planet and Neptune is the farthest
planet from the sun.
(v) Venus because of its shape and size is similar to the earth is
considered as 'Earth's-twin'.
(vi) Till August 2006, Pluto was also a planet. But now it is
called only a celestial body.
(vii) Jupiter, Saturn and Uranus have rings around them. These
are belts of small debris. These rings may be seen from the
earth with the help of powerful telescopes.

12. PEER INSTRUCTIONS
 The following is (are) true about Sun.
I. It is made up of gases
II. It has its own heat and light
III. Sun is a star
a. I is true but II and III is false
b. I and III are true But II is false
c. II and III are True but I is false
d. All are true
e. All are false

13.  Neha is reading an article about ‘dwarf planet’,
So she is reading about
a) Saturn
b) Jupiter
c) Mars
d) Pluto
The following planet is nearest to the Sun.
a) Mars
b) Mercury
c) Venus
d) Saturn

14.  If a new planet “A” found between the Neptune and
Uranus, than
a. It one orbit around sun will be less than Uranus
b. It one orbit around sun will be less than Neptune
c. It one orbit around sun will be More than Neptune

15. THE EARTH
(i) The earth is the fifth largest planet in size while the
third nearest planet to the sun and is our home.
(ii) It is slightly flattened at the poles. That is why, its
shape is called Geoid.
(iii) Conditions favourable to support life are found only
on the earth which can be listed as follows-
(a) presence of air with life supporting gases like oxygen
(b) neither extremely hot nor extremely cold
(c) presence of water
(iv) From the outer space, the earth appears blue
because its 2/3rds surface is covered by water. It is,
therefore, called a blue planet.

16. THE MOON
(i) Our earth has only one natural satellite that is the
moon.
(ii) It appears so big because it is nearer to our planet than
other celestial bodies.
(iii) The moon moves around the earth in about 27 days
and 8 hours. It takes exactly the same time to complete
one spin of earth. This makes only one side of the moon
visible from the earth.
(iv) The moon does not have conditions favourable for life.
The surface of the moon is covered with plains,
mountains and depressions which is observable as
shadows on full moon day.

18. PEER INSTRUCTIONS
The following planet is known as blue planet.
a) Mars
b) Mercury
c) Venus
d) Earth
The moon moves around the earth in about _____
days.
a) 25
b) 26
c) 27
d) 28

19. The following planet has maximum number of
moons.
a) Jupiter
b) Saturn
c) Uranus
d) Neptune
The following planet takes maximum time for one
orbit around sun
a) Neptune
b) Mercury
c) Saturn
d) Uranus

20. ASTEROIDS
(i) There are numerous tiny bodies which also move
around the sun. These bodies are called asteroids.
(ii) They are found between the orbits of Mars and
Jupiter.
(iii) The scientists believe that these are the parts of a
planet, which are formed by the explosion of that
planet many years ago.
(iv) Ceres is the largest asteroids

21. METEOROIDS
(i) The small pieces of rocks which move around the
sun are called meteoroids.
(ii) Sometimes these objects come close to the earth
and drop upon it. While dropping on the earth
they get heated up and burn due to friction with
the air and appear as a flash of light. Meteors
sometimes do not get burnt completely and strike
the earth surface creating a hollow.

22. PEER INSTRUCTIONS
Asteroids are found between the orbit of
a) Mars and Saturn
b) Mars and Venus
c) Mars and Jupiter
d) Mars and Mercury