NCERT Solutions Class 8 Science Chapter 17 Stars and The Solar System
1. Which of the following is NOT a member of the solar system?
(a) An asteroid
(b) A satellite
(c) A constellation
(d) A comet
Solution:
Answer is (c) A constellation
Explanation:
A constellation is not a member of the solar system. These are the group of stars that forms a recognizable shape and is known as Constellation.
2. Which of the following is NOT a planet of the sun?
(a) Sirius
(b) Mercury
(c) Saturn
(d) Earth
Solution:
Answer is (a) Sirius
Explanation:
Sirius is a star, not the planet of the solar system.
3. Phases of the moon occur because
(a) we can see only that part of the moon which reflects light towards us.
(b) our distance from the moon keeps changing.
(c) the shadow of the Earth covers only a part of the moon’s surface.
(d) the thickness of the moon’s atmosphere is not constant.
Solution:
Answer is (a) we can see only that part of the moon which reflects light towards us.
Explanation:
Moon does not have its own light. It is only be seen by us when sunlight falls on the moon and gets reflected towards us. So, we can only see the part of the moon on which the sunlight falls and reflects towards us.
4. Fill in the blanks.
(a) The planet which is farthest from the Sun is ____________ .
(b) The planet which appears reddish in colour is ____________ .
(c) A group of stars that appear to form a pattern in the sky is known as a ____________ .
(d) A celestial body that revolves around a planet is known as __________.
(e) Shooting stars are actually not ____________.
(f) Asteroids are found between the orbits of _________ and _________ .
Solution:
(a) The planet which is farthest from the Sun is Neptune.
(b) The planet which appears reddish in colour is Mars.
(c) A group of stars that appear to form a pattern in the sky is known as a Constellation.
(d) A celestial body that revolves around a planet is known as satellite.
(e) Shooting stars are actually not stars.
(f) Asteroids are found between the orbits of Mars and Jupiter .
5. Mark the following statements as true (T) or false (F).
(a) Pole star is a member of the solar system. ( )
(b) Mercury is the smallest planet of the solar system. ( )
(c) Uranus is the farthest planet in the solar system. ( )
(d) INSAT is an artificial satellite. ( )
(e) There are nine planets in the solar system. ( )
(f) Constellation Orion can be seen only with a telescope. ( )
Solution:
(a) False
Concept Insight: Pole Star is not a member of the Solar System.
(b) True
(c) False
Concept Insight: Neptune is the farthest planet in the solar system.
(d) True
(e) False
Concept Insight: There are eight planets in the Solar System. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
(f) False
Concept Insight: Constellation Orion can be seen during winters around late evenings. It is one of the most magnificent constellations in the sky, visible to the naked eyes.
6. Match items in column A with one or more items in column B.
A |
B |
(i) Inner planets |
(a) Saturn |
(ii) Outer planets |
(b) Pole star |
(iii) Constellation |
(c) Great Bear |
(iv) Satellite of the Earth |
(d) Moon |
|
(e) Earth |
|
(f) Orion |
|
(f) Orion |
Solution:
A |
B |
(i) Inner planets |
(g) Mars, (e) Earth |
(ii) Outer planets |
(a) Saturn |
(iii) Constellation |
(c) Great Bear, (f) Orion |
(iv) Satellite of the Earth |
(d) Moon |
7. In which part of the sky can you find Venus if it is visible as an evening star?
Solution:
The planet Venus is found in the western part of the sky after sunset and is said to be known as an evening star.
8. Name the largest planet of the solar system.
Solution:
Jupiter is the largest planet of the solar system.
9. What is a constellation? Name any two constellations.
Solution:
The group of stars that forms a recognizable pattern in the sky is known as a constellation.
Two constellations are; Ursa Major and Orion
10. Draw sketches to show the relative positions of prominent stars in (a) Ursa Major and (b) Orion
Solution:
a) Orion seems to be like a hunter. The three bright stars appear in the belt, while four bright stars are arranged in the form of a quadrilateral.
b) Ursa Major seems to be like a big dipper. There are four stars in the bowl of the dipper and three bright stars in the handle.