Worksheet solutions for chapter: Stars and the Solar System for class 8 are provided below.
(1) Write the differences between the new moon day and full moon day.
Differences between the full moon day and new moon day are listed below-
|New Moon Day||Full Moon Day|
|The Moon is not visible.||The Moon is visible.|
|The Earth comes inbetween the Moon and Sun.||The Moon comes in between the the Earth and the Sun.|
|The Moon begins to glow Dy by day after new moon day and fully grows on the fifteenth day.||The Moon begins to thin after full moon day and disappear completely on fifteenth day after full moon day.|
(2) There is no life on the Moon. Give reason.
Water and oxygen are very necessary for the life. Both are not find on the Moon. Therefore, no life is possible on the Moon.
(3) Why we can not see the back side of the Moon from the Sun?
The time taken in one rotation by the Moon on its axis is almost equal to time taken to complete one revolution around the earth. It means we are seeing same side of the Moon every time. Therefore, we can not see the back side of the Moon from the Earth.
(4)Why stars are only visible at the night?
The stars are very far from our earth and always present in the sky. The Sun is the only star near to us. It produces bright sunlight. Therefore, we can not able to watch other stars in bright light of the Sun.
(5)Why the Sun appears to rise in the east and set in the west?
The stars including the Sun appears to move from east to west. It happens because of the rotation of the Earth on its axis. It rotates from west to east. It completes one rotation in 24 hours. Therefore, after every 24 hours, the Sun appears to rise in the east and set in the west.
(6) Planets revolve around the Sun. But they do not collide. Why?
The gravitational attraction between the Sun and the planets keep planets revolving around the Sun. Hence, planets never collide.
(7) Is the Earth a satellite or planet?
The Earth is a planet because it revolves around the Sun. Satellites are those celestial body which revolves around the planets. The Sun is a star and planets revolves around the Sun. Therefore, The Earth is a planet.
(8) Why the Venus planet is called morning or evening star.
Sometimes Venus appears in the eastern sky before sunrise. Sometimes it appears in the evening sky just after sunset. Hence, the Venus is called as a morning or evening star.
(9)If I am 13 years old, how many times have I gone round the Sun?
The Earth completes one resolution around the Sun in 365 days or in one year. Therefore, if you are 13 years old you must have gone around the Sun 13 times.
(10) Write differences between outer planet and inner planet.
Differences between the inner and outer planet are listed below-
|Inner Planet||Outer Planet|
|These are first four planet of the solar system.||These are last four planet of the solar system.|
|These planets are very close to the Sun.||These planets are far away from the Sun.|
|These planets have very few moons.||These planets have large number of moons.|
|These planets do not have rings around them.||These planets have ring system around them.|
|Eg:- Mercury, mars, earth , Venus.||Eg:- Jupiter, Saturn, Uranus and Neptune.|