Stars and the Solar System Class 8 Extra Questions and Answers

These AP 8th Class Physics Important Questions and 11th Lesson Stars and the Solar System Class 8 Extra Questions will help students prepare well for the exams.

Class 8 Science Stars and the Solar System Extra Questions

Stars and the Solar System Class 8 Important Questions

Question 1.
What causes the sky in the big cities rarely clear ?
Answer:
Due to bright light, smoke and dust, the sky in big cities is rarely clear.

Question 2.
How do you identify the planets in the night sky ?
Answer:
The objects which do not twinkle are planets in the sky.

Question 3.
Which is the brightest object in the night sky ?
Answer:
The moon is the brightest object in the night sky.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 4.
What are celestial objects ?
Answer:
The stars, the planets, the moon and many other objects in the sky are called celestial objects.

Question 5.
What is astronomy ?
Answer:
The study of celestial objects and associated phenomena is called astronomy.

Question 6.
What helped our ancestors to make devise calendars and almanacs ?
Answer:
Passage of the Sun, stars, moon and planets in the sky helped them to devise calendars and almanacs.

Question 7.
What is a full moon day ?
Answer:
The day on which the whple disc of the moon is visible is known as the full moon day.

Question 8.
What is the crescent moon ?
Answer:
The next day after a new moon day only a small portion of the moon appears in the sky. This is known as the crescent moon.

Question 9.
When does a new moon day come ?
Answer:
On the fifteenth day after the full moon day, the moon is not visible. This day is known as the ‘new moon day’.

Question 10.
What are the phases of the moon ?
Answer:
The various shapes of the bright part of the moon as seen during a month are called phases of the moon.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 11.
What is a month ?
Answer:
The time period between one full moon to the next full moon is slightly longer than 29 days. In many calendars, this period is called a month.

Question 12.
Can any life exist on the moon ? Why ?
Answer:
No, the moon has no atmosphere. It has no water on the surface. So, no life exists.

Question 13.
Can we hear any sound on the moon ? Why ?
Answer:
No, we cannot here because there is no medium to propagate the sound.

Question 14.
Who was the first astronaut to land on the Moon ?
Answer:
On July 21, 1969 (Indian time) the American astronaut, Neil Armstrong, landed on the moon for, the first time. He was followed by Edwin Aldrin.

Question 15.
Why does the sun appear so large compared to the other stars ?
(OR)
Why do the stars other than the sun appear as tiny points ?
Answer:
The stars are millions of times farther away than the Sun. Therefore, the stars appear to us like points. The sun is very nearer to the earth. So, it appears bigger.

Question 16.
What is a light year ?
Answer:
The distance travelled by light in one year is called a light year.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 17.
What is the next nearest star to the earth ?
Answer:
The next nearest star is Proxima Centauri. It is at a distance of about 40,000,000,000,000 km from the Earth.

Question 18.
What is the necessity of the unit light year ?
Answer:
Stars are even further away from the earth. We cannot read the large distances in kilometres conveniently. So, such large distances are expressed in the unit known as the light year.

Question 19.
Do you find any change in the positions of stars in the sky ?
Answer:
We will find that the stars appear to move from east to west. A star that rises in the east in the evening sets in the west in the early morning.

Question 20.
Why the Sun appears to rise in the east and set in the west ?
Answer:
As the Earth rotates from west to east on its axis the Sun appears to rise in the east and set in the west.

Question 21.
What are constellations ?
Answer:
The stars forming a group that has a recognizable shape is called a constellation.

Question 22.
What are the other names of the Ursa Major ?
Answer:
Ursa Major is also known as the Big Dipper, the Great Bear or the Saptarshi.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 23.
Which constellation is called Hunter ?
Answer:
Orion is also called the Hunter.

Question 24.
What is Sirius ?
Answer:
Sirius is a star, which is the brightest star in the sky, is located close to Orion.

Question 25.
What is meant by the Solar system ?
Answer:
The Sun and the celestial bodies which revolve around it form the solar system.

Question 26.
What is an orbit ?
Answer:
A planet has a definite path in which it revolves around the Sun. This path is called an orbit.

Question 27.
What is a period of rotation ?
Answer:
The time taken by a planet to complete one rotation is called its period of rotation.

Question 28.
What is a satellite ?
Answer:
Any celestial body revolving around another celestial body is called its satellite.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 29.
The Earth revolves around the Sun. Does it make Earth a satellite of the Sun ?
Answer:
The Earth can be said to be a satellite of the Sun.

Question 30.
What is the satellite of the earth ?
Answer:
Moon is a satellite of the Earth.

Question 31.
What are the artificial satellites ?
Answer:
There are many man-made satellites revolving around the Earth. These are called artificial satellites.

Question 32.
What is the smallest planet in the solar system ?
Answer:
Venus is the smallest planet of our solar system.

Question 33.
How does the appear from the space ? Why ?
Answer:
From space, the Earth appears blue-green due to the reflection of light from water and landmass on its surface.

Question 34.
What is responsible for the formation of seasons on the earth ?
Answer:
The axis of rotation of the Earth is not perpendicular to the plane of its orbit. The tilt is responsible for the change of seasons on the Earth.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 35.
Which planet in our solar system is the largest planet ?
Answer:
Jupiter is the largest planet in the solar system. It is so large that about 1300 earths can be placed inside this giant planet.

Question 36.
What are the inner planets ?
Answer:
The first four planets, Mercury, Venus, Earth and Mars are much nearer the Sun than the other four planets. They are called the inner planets.

Question 37.
What are the outer planets ?
Answer:
The planets outside the orbit of Mars, namely Jupiter, Saturn, Uranus and Neptune are much farther off than the inner planets. They are called the outer planets.

Question 38.
What are asteroids ?
Answer:
There is a large gap in between the orbits of Mars and Jupiter. This gap is occupied by a large number of small objects that revolve around the Sun. These are called asteroids.

Question 39.
What are comets ?
Answer:
Comets revolves around the sun in an particular orbit with as a bright head with a long tail.

Question 40.
What are meteors ?
Answer:
A meteor is usually a small object that occasionally enters the earth’s atmosphere.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 41.
What are meteor showers ?
Answer:
When the Earth crosses the tail of a comet, swarms of meteors are seen. These are known as meteor showers.

Question 42.
What are Artificial satellites ?
Answer:
Artificial satellites are man-made. They are launched from the Earth. They revolve around the Earth much closer than earth’s natural satellite, the moon.

Question 43.
Give examples to artificial satellites of India.
Answer:
Aryabhatta was the first Indian satellite. Some other Indian satellites are INSAT, IRS, Kalpana-1, EDUSAT, etc.

Question 44.
What is meant by remote sensing ?
Answer:
Remote sensing mean collecting information from a distance.

Question 45.
We know that the moon does not produce its own light. How can we see the moon?
Answer:

  1. The moon does not produce its own light, whereas the Sun and other stars do.
  2. We see the moon because the sunlight falling on it gets reflected towards us.
  3. We, therefore, see only that part of the moon, from which the light of the Sun is reflected towards us.

Question 46.
How the size of the illuminated part of the moon visible from the Earth each day ?
Answer:

  1. The illuminated part of the moon visible from the Earth increases each day after the new moon day.
  2. After the full moon day, the sunlit part of the moon visible.from the Earth decreases in size every day.

Question 47.
I have heard that we never see the back side of the moon from the Earth. Is it true? Why?
Answer:
Yes, because the moon rotates around the Earth at the exact same speed as it rotates around its own axis so that the same side of the moon is constantly facing the surface of the earth.

Question 48.
Why we do not see the stars during the day. Why are they visible only at night ?
Answer:

  1. The stars are present in the sky during the day time also. However, they are not visible then because of the bright sunlight.
  2. At night they are visible because the sunlight does not interfere with our vision.

Question 49.
Name the star in the sky that does not move at all. How is it possible ?
Answer:

  1. The pole star, in the sky, does not move at all.
  2. It is situated in the direction of the earth’s axis. So it does not appear to move.

Question 50.
Do you find any change in the shape of a constellation? Do you find any change in its position ?
Answer:
We will observe that the shape of the constellation remains the same. We will also find tha the constellation appears to move in the sky from east to west.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 51.
Does Ursa Major appear to revolve around the Pole star ?
Answer:
All the stars in the Ursa Major appear to revolve around the Pole star.

Question 52.
What is Orion ?
Answer:
Orion is another well-known constellation that can be seen during winter in the late evenings. It is one of the most magnificent constellations in the sky. It also has seven or eight bright stars.

Question 53.
Write about Cassiopeia.
Answer:
Cassiopeia is another prominent constellation in the northern sky. It is visible during winter in the early part of the night. It looks like a distorted letter W or M.

Question 54.
What is a constellation ? Give examples.
Answer:

  1. Constellation is a group of stars that appears in the sky.
  2. Examples: Orion, Ursa Major, Cassiopeia.

Question 55.
How many planets are revolving around the sun?
Answer:

  1. There are eight planets that revolve around he Sun.
  2. The eight planets.in their order of distance from the Sun are Mercury; Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Question 56.
Write about the sun in the solar system.
Answer:
The Sun is the nearest star from us. It is continuously emitting huge amounts of heat and light. The Sun is the source of almost all energy on the Earth. In fact, the Sun is the main source of heat and light for all the planets.

Question 57.
What is a period of revolution? How does it change ?
Answer:

  1. The time taken by a planet to complete one revolution is called its period of revolution.
  2. The period of revolution increases as the distance of the planet increases from the sun.

Question 58.
Which planet is called as a morning or an evening star ? Why ?
Answer:
The planet, Venus appears in the eastern sky before sunrise. Sometimes it appears in the western sky just after sunset. Therefore, it is often called a morning or an evening star.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 59.
What is Halley’s comet ? When was it appeared ?
Answer:
Halley’s comet, which appears after nearly every 76 years. It was last seen in 1986.

Question 60.
What are meteorites ? How do they help ?
Answer:

  1. The body of the meteor that reaches the Earth is called a meteorites.
  2. Meteorites help scientists in investigating the nature of the material from which the solar system was formed.

Question 61.
Which planet is called a red planet ? Why ?
Answer:
Mars is called the red planet. It is slightly reddish and therefore, it is called the red planet.

Stars and the Solar System Extra Questions

Question 1.
How do you say that our ancestor’s knowledge of astronomy was highly advanced for their time ?
Answer:

  1. In ancient India our ancestors performed methodical observations of the sky.
  2. Their knowledge of astronomy was highly advanced for their time.
  3. Passage of the Sun, stars, moon and planets in the sky helped them to devise calendars and almanacs.
  4. These were often used by people in their day-to-day conduct and a better understanding of climate and rainfall patterns for timely sowing and choice of crops, fixing the dates of seasons and festivals.

Question 2.
Why does the moon change its shape every day ?
Answer:

  1. Half of the moon illuminates by reflecting the light of the sun light. Remaining part in the moon in the shadow.
  2. As the Earth along with the moon, revolves around the Sun, we can see some illuminated part and other shadow part of the moon from the earth.
  3. Every day, from the illuminated part increases from the new moon day and decreaes from full moon day and inreases from new moon day.

Question 3.
How is the moon’s surface ?
Answer:

  1. The moon’s surface is dusty and barren.
  2. There are many craters of different sizes.
  3. It also has a large number of steep and high mountains.
  4. Some of these are as the highest mountains on the Earth.

Question 4.
What is Ursa Major ? What does its look like ?
Answer:

  1. The most famous constellations which we can see during summer time in the early part of the night is Ursa Major.
  2. It is also known as the Big Dipper, the Great Bear or the Saptarshi.
  3. There are seven prominent stars in this constellation.
  4. It appears like a big ladle or a question mark.
  5. There are three stars in the handle of the ladle and four in its bowl.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 5.
What is the brightest star in the night sky ? How do you locate it ?
(OR)
Write about Sirius.
Answer:

  1. The star Sirius, which is the brightest star in the sky, is located close to Orion.
  2. To locate Sirius, imagine a straight line passing through the three middle stars Orion.
  3. Look along this line towards the east. This line will lead you to a very bright star, is Sirius.

Question 6.
How does a constellation form?
Answer:

  1. A constellation does not have only 5 – 10 stars. It has a large number of stars.
  2. However, we can see only the bright stars in a constellation with our naked eyes.
  3. All the stars which make up a constellation are not at the same distance
  4. They are just in the same line of sight in the sky.

Quetsion 7.
What are celestial bodies contained in our solar system ? How do they revolve around the sun ?
Answer:

  1. The solar system consists of the large number of bodies such as planets, comets, asteroids and meteors.
  2. The gravitational attraction between the Sun and these objects keeps them revolving around it.

Question 8.
How do you identify both the planets and stars in the sky ?
Answer:

  1. The simplest method of identifying planets from stars is that stars twinkle, whereas planets do not.
  2. Also, the planets keep changing their positions with respect to the stars.

Question 9.
Write a difference between a period of revolution and a period of rotation.
Answer:

  1. The time taken by a planet to complete one revolution is called its period of revolution.
  2. The time taken by a planet to complete one rotation is called its period of rotation.

Question 10.
Write about the position of the earth in the solar system.
Answer:

  1. The Earth, revolves around the Sun.
  2. It is a member of the solar system.
  3. It is a planet.
  4. There are seven other planets that revolve around the Sun.
  5. The eight planets in their order of distance from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Question 11.
What conditions made the earth with living beings ?
(OR)
The Earth is the only planet in the solar system on which life is known to exist. Why?
Answer:

  1. The Earth is the only planet in the solar system on which life is known to exist.
  2. Some special environmental conditions are responsible for the existence and continuation of life on the Earth.
  3. These include just the right distance from the Sun, so that it has the right temperature range, the presence of water and suitable atmosphere and a blanket of ozone.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 12.
Write about comets.
Answer:

  1. Comets are also members of our solar system. They revolve around the Sun in highly elliptical orbits.
  2. However, their period of revolution around the Sun is usually very long.
  3. A Comet appears generally as a bright head with a long tail.
  4. The length of the tail grows in size as it approaches the Sun. The tail of a comet is always directed away from the Sun.

Question 13.
What are the uses of the artificial satellites ?
Answer:

  1. Artificial satellites have many practical applications,
  2. They are used for forecasting weather, transmitting television and radio signals.
  3. They are also used for telecommunication and remote sensing.

Question 14.
Write about Mangalyaan.
Answer:

  1. Indian Space Research Organisation (ISRO) launched India’s first Mars orbiter mission – Mangalyaan, on November 5, 2013.
  2. It was successfully placed into an orbit of Mars on September 24, 2014.
  3. With this India became the first country in the world to do so in its first attempt.

Extra Questions of Stars and the Solar System Class 8

Question 1.
How do you say taht the phases of the moon play an important role in our social life?
Answer:

  1. Phases of the moon play an important role in our social life.
  2. Almost all festivals in India are celebrated according to the phases of the moon.
  3. For example, Diwali is celebrated on the new moon day.
  4. Buddha Purnima and Guru Nanak’s birthdays are celebrated on full moon day.
  5. Maha Shivaratri is celebrated on the thirteenth night of the waning moon.
  6. Eid-ul-Fitr is observed on the day following the sighting of the crescent moon.

Question 2.
Write about the Pole star.
Answer:

  1. Pole star appears on the north side.
  2. It seems to not move.
  3. It appears not a too bright star.
  4. It is located on the earth’s axis.
  5. It is very useful for navigators.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 3.
Write about Orion.
Answer:

  1. Orion is another well-known constellation that can be seen during winter in the late evenings.
  2. It is one of the most magnificent constellations in the sky.
  3. It also has seven or eight bright stars.
  4. Orion is also called the Hunter.
  5. The three middle stars represent the belt of the hunter.
  6. The four bright stars appear to be arranged in the form of a quadrilateral.

Question 4.
Write the greatness of the Aryabhatta.
Answer:

  1. One of the most well known astronomers is Aryabhatta.
  2. The work of Aryabhatta on astronomy can be found in his writing ‘Aryabhatiya’.
  3. He wrote it in 499 CE at the age of 23 years.
  4. The diameter of the Earth as stated by Aryabhatta is close to its presently known value stated that Earth is sphere and rotates on its own axis.
  5. His estimate about the side real period of Earth was 23 hours, 56 minutes and 4.1 seconds, which is very close to the presently known value.

Question 5.
Distinguish between planets and stars.
Answer:

Planets Stars
1) Planets illuminate by reflecting the light of the star. 1) Stars are self-luminous.
2) Planets revolve around a star. 2) Stars revolve around a galaxy.
3) The earth is an example of a planet. 3) The sun is an example of a star.
4) Planets are smaller than their central star. 4) Stars are larger than their planets.
5) Planets do not release heat and energy. 5) Stars always release heat and energy.

Question 6.
Differentiate inner and outer planets.
Answer:

Inner planets Outer planets
1) The first four planets, Mercury, Venus, Earth and Mars are much nearer the Sun than the other four planets. They are called the inner planets. 1) The planets outside the orbit of Mars, namely Jupiter, Saturn, Uranus and Neptune are much farther off than the inner planets. They are called the outer planets.
2) They have a ring system around them. 2) They have a ring system around them.
3) The inner planets have very few moons. 3) The outer planets have large number of moons.

Question 7.
What are the questions that engage your mind when you look at night sky ?
Answer:

  1. Is stars collide with each other ? ¦
  2. Where does the stars go in the morning ?
  3. Whether stars daily travel in the same path ?
  4. Why night sky is black and early morning sky is blue ?
  5. Whether we can count stars in the sky ?
  6. Why stars grouped to form constellations ?

Question 8.
What are the planets you have seen in the sky ? When do you observe those planets?
Answer:
The two planets observe in the sky are

  1. Venus : Sometimes Venus appears in the eastern sky before sunrise. Sometimes it appears in the western sky just after sunset. Therefore it is often called a morning or an evening star.
  2. Mars : It appears slightly reddish and therefore, it is also called red planet. It appears in the east.

Stars and the Solar System Class 8 Extra Questions and Answers

Question 9.
Study the table given below and answer the questions.

Name of the Planet Distance from the sun in crore km. Period of revolution No. of Satellites
Mercury 5.79 88 days 0
Earth 15 365 days 1
Mars 22.8 687 days 2
Jupiter 77.8 12 years 50
Saturn 142.7 29.5 years 53
Neptune 449.7 165 years 13

i) Name the planets with least and highest number of moons.
Answer:
Earth has only one moon. Hence it has least number of moons.
Saturn has highest number of moons.

ii) Which of tfye above planets is hottest ? Why ?
Answer:
Mercury is hottest, because it has very closer to the sun.

iii) Name any one of inner and outer planets.
Answer:
Inner planet is Mercury.
Outer planet is Mars.

iv) Which planet’s satellite is larger than the natural satellite of our earth ?
Answer:
Jupiter’s satellite (Ganymede) is larger than the natural satellite of our earth.

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