NCERT Solutions for Class 8 Science Chapter 17 - Stars and the Solar System

Question 1:

Which of the following is NOT a member of the solar system?

  1. An asteroid
  2. A satellite
  3. A constellation
  4. A comet
Answer:

A constellation

Question 2:

Which of the following is NOT a planet of the Sun?

  1. Sirius
  2. Mercury
  3. Saturn
  4. Earth
Answer:

Sirius

Question 3:

Phases of the Moon occur because

  1. we can see only that part of the Moon which reflects light towards us.
  2. our distance from the Moon keeps changing.
  3. the shadow of the Earth covers only a part of the Moon’s surface.
  4. the thickness of the Moon’s atmosphere is not constant.
Answer:

we can see only that part of the Moon which reflects light towards us.

Question 4:

The planet which is farthest from the Sun is ____________.

Answer:

Neptune

Question 5:

The planet which appears reddish in colour is ____________.

Answer:

Mars

Question 6:

A group of stars that appear to form a pattern in the sky is known as a ____________.

Answer:

Constellation

Question 7:

A celestial body that revolves around a planet is known as ___________.

Answer:

Satellite

Question 8:

Shooting stars are actually not ____________.

Answer:

Stars

Question 9:

Asteroids are found between the orbits of ___________and ___________.

Answer:

Mars, Jupiter

Question 10:

Pole Star is a member of the solar system.

  1. TRUE
  2. FALSE
Answer:

TRUE

Question 11:

Mercury is the smallest planet of the solar system.

  1. TRUE
  2. FALSE
Answer:

TRUE

Question 12:

Uranus is the farthest planet in the solar system.

  1. TRUE
  2. FALSE
Answer:

FALSE

Question 13:

INSAT is an artificial satellite.

  1. TRUE
  2. FALSE
Answer:

TRUE

Question 14:

There are nine planets in the solar system.

  1. TRUE
  2. FALSE
Answer:

FALSE

Question 15:

Constellation Orion can be seen only with a telescope.

  1. TRUE
  2. FALSE
Answer:

FALSE

Question 16:

Match the items in column A with one or more items in column B.

  1. TRUE
  2. FALSE
Answer:

FALSE

Question 17:

Match the items in column A with one or more items in column B.

  1. Inner planets
  2. Outer planets
  3. Constellation
  4. Satellite of the Earth
Answer:

(i). (b), (ii). (a), (iii). (c), (iv). (d)

Question 18:

In which part of the sky can you find Venus if it is visible as an evening star?

Answer:

Venus is visible as an evening star in the western part of the sky

Question 19:

Name the largest planet of the solar system.

Answer:

Jupiter

Question 20:

What is a constellation? Name any two constellations.

Answer:

A groups of stars that appear to form recognisable shapes/patterns are called constellations. The Great Bear and Orion are two constellations.

Question 21:

Draw sketches to show the relative positions of prominent stars in (a) Ursa Major and (b) Orion

Answer:

Question 22:

Name two objects other than planets which are members of the solar system.

Answer:

Asteroids and Meteors

Question 23:

Explain how you can locate the Pole Star with the help of Ursa Major.

Answer:

The Pole Star is located at the end of Ursa Major. A straight line from the last two stars when extended towards the north leads to the Pole Star.

Question 24:

Do all the stars in the sky move? Explain.

Answer:

No, all stars in the sky do not move. However, they appear to move from east to west due to the rotation of the Earth about its axis.

Question 25:

Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the Earth?

Answer:

Stars are situated very far (many millions of kilometres) away from the Earth. Such large distance cannot be conveniently expressed in kilometres. Hence, it is expressed in a unit called light year. One light year is the distance travelled by light in one year. One light year is equivalent to 9.46 × 1012 km. If we say that a star is eight light years away from earth, it means that the light from the star will reach the earth in eight years.

Question 26:

The radius of Jupiter is 11 times the radius of the Earth. Calculate the ratio of the volumes of Jupiter and the Earth. How many Earths can Jupiter accommodate?

Answer:

Question 27:

Boojho made the following sketch of the solar system. Is the sketch correct? If not, correct it.

Answer:

The sketch is not correct. The correct sketch is as follows: