Class–VIII (CHAPTER-17) Stars and the Solar System
Questio
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
2. Which of the following is NOT a planet of the sun? (a) Sirius
(b) Mercury (c) Saturn (d) Earth
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
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 a
.
(e) Shooting stars are actually not .
(f) Asteroids are found between the orbits of and .
5. Mark the following statement 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. ( )
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 (g) Mars
7. In which part of the sky can you find Venus if it is visible as an evening star?
8. Name the largest planet of the solar system.
9. What is a constellation? Name any two constellations.
10. Draw sketches to show the relative position of prominent stars in
(a) Ursa Major
(b) Orion
11. Name two objects other than planets which are members of the solar system.
12. Explain how you can locate the Pole Star with the help of Ursa
Major.
13. Do all the stars in the sky move? Explain.
14. 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?
15. 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?
16. Boojho made the following sketch (Fig.) of the solar system. Is the sketch correct? If not, correct it.
Class–VIII (CHAPTER-17) Stars and the Solar System
Answers
1. (c) Constellation
Constellations are group of stars that forms some definite recognizable shapes.
2.
(a) Sirius
Sirius is a star and not a planet of the sun.
3. (a) we can see only that part of the moon which reflects light towards us.
Moon does not has its own light but it reflects the light coming
from the sun.
4.
(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 a
satellite.
(e) Shooting stars are actually not stars.
(Shooting stars are not stars, they are meteors).
(f) Asteroids are found between the orbits of Mars and Jupiter.
(Asteroids occupy a large gap between the orbits of Mars and
Jupiter)
5.
(a) T
(Pole star is a member of solar system.) (b) T
(c) T (d) T (e) F
There are eight planets in our solar system. (f) F
The constellation Orion is visible to the naked eyes during
Winters.
6.
A B
(i) Inner planets (g), (e) Mars, Earth
(ii) Outer planets (a) Saturn
(iii) Constellation (c), (f) Great Bear, Orion
(iv) Satellite of the Earth (d) Moon
7. Venus can be found on the west side of the sky. It is also known as evening star.
8. Jupiter is the largest planet of the solar system.
9. A group of stars which has a recognizable shape is called a constellation. Two well-known constellations are great Bear and
Orion.
10.
(a) The constellation Ursa Major contains the group of stars commonly called the Big Dipper. The handle of the Dipper is the Great Bear's tail and the Dipper's
(b) Orion is a prominent constellation which appears like a hunter and is visible throughout the world. It is one of the most recognizable constellations in the night sky.
11.
(i) Comet
Comets are cosmic snowballs of frozen gases, rock and dust that orbit the Sun.
(ii) Asteroids
Asteroids are small, rocky objects that orbit the sun. Although asteroids orbit the sun like planets, they are much
smaller than planets.
12. Pole star can be located with the help of the three stars at the end of Ursa Major. We can imagine a straight line passing through these stars and extend the imaginary line in north direction. A star is to be seen in this direction. This is pole star.
. No, all the stars do not move in the sky. They appear to move from east to west due to the rotation of earth. Pole star does not appear to move and remains stationary.
14. Stars are very far away from each other. The distance between sun and earth is 150,000,000 km, whereas the distance of alpha century is 40,000,000,000,000 km. It is not convenient to write in
km. So, it is expressed in light year. One light year is equal to
9.46 ×10^12 km.
A light year is the distance covered by light in one year. Eight light year means the distance covered by light in eight years.
15. Let the radius of Earth and Jupiter be R and R'.
