Stars and the Solar System Class 8 Science chapter 17 Extra Questions and Answers are provided here. We prepared these extra questions based on the latest NCERT Class 8 Science Book. CBSE Class 8 Science Chapter 17 Stars and the Solar System Extra Questions will help you to properly understand a particular concept of the chapter.

Class 8 Science Chapter 17 Stars and the Solar System Extra Questions

Very Answer Type Question

Question 1: Which is the nearest planet to the Sun?

Answer: Mercury is the planet nearest to the Sun.

Question 2: What is a satellite?

Answer: A body revolving around another body is called a satellite.

Question 3: Which is the farthest planet to the Sun?

Answer: Neptune is the farthest planet to the Sun.

Question 4: Which two planets show phases like the Moon?

Answer: Mercury and Venus show phases like the Moon.

Question 5: Which planet has large number of satellites?

Answer: Jupiter has a large number of satellites.

Question 6:  Which was the first artificial satellite launched by India?

Answer: Aryabhatta was the first Indian satellite.

Question 7: Which two planets have asteroids between them?

Answer: Mars and Jupiter have asteroids between them.

Question 8: Which is the only natural satellite of Earth?

Answer: Moon is the only natural satellite of the Earth.

Question 9: Name some artificial satellites of the Earth.

Answer: INSAT, IRS, Kalpana-1, EDUSAT

Question 10: What is a light year?

Answer: Light year is the distance travelled by light in one year.

Question 11: What is the speed of light?

Answer: The speed of light is about 300,000 km per second.

Question 12: What time of year is the constellation Ursa Major visible?

Answer: Ursa Major can be seen during summer time.

Question 13: What is the smallest planet in the solar system?

Answer: Mercury is the smallest planet in the solar system.

Question 14: Which planet is the biggest planet in the solar system?

Answer: Jupiter is the biggest planet in the solar system.

Question 15: Name the largest planet of the solar system.

Answer: Jupiter is the largest planet of the solar system.

Question 16: How large is Jupiter compared to Earth?

Answer: The mass of Jupiter is about 318 times that of our Earth.

Question 17: What is a star?

Answer: Stars are celestial bodies that emit light of their own.

Question 18: How many planets are there in the Solar System?

Answer: There are eight planets in the solar system.

Question 19: How many prominent stars are present in the Orion constellation?

Answer: It has seven or eight bright stars.

Question 20: How long does it take light to travel from Alpha Centauri to Earth?

Answer: It takes sunlight 4.3 years to travel from the Sun to the Earth.

Question 21: What is Ursa Major also known as?

Answer: It is also known as the Big Dipper, the Great Bear or the Saptarshi.

Question 22: Which is the smallest planet of the solar system?

Answer: Mercury is the smallest planet of our solar system.

Question 23: Which constellation appears to have the shape of a hunter?

Answer: Orion is the constellation which appears to have the shape of a hunter.

Question 24: How many prominent stars are present in the Ursa Major constellation?

Answer: There are seven prominent stars in the Ursa Major constellation.

Question 25: What is the ultimate source of heat and light for the solar system?

Answer: Sun is the ultimate source of heat and light for the solar system.

Question 26: In which season of the year is the Cassiopeia constellation visible in the night sky?

Answer: Cassiopeia is visible during winter in the early part of the night.

Question 27: Name two objects other than planets which are members of the solar system.

Answer: Asteroids and Meteors

Question 28: Name one constellation which is visible in the sky in the summer season.

Answer: Ursa Major

Question 29: Name two constellations which are visible in the sky in the winter season.

Answer: Orion and Cassiopeia

Question 30: Which celestial body is seen as a bright streak of light coming down the night sky?

Answer: Meteor is seen as a bright streak of light coming down the night sky.

Question 31: Which constellation appears to have the shape of a big lion?

Answer: Leo Major is the constellation which appears to have the shape of a big lion.

Question 32: How many planets are between Earth and the Sun? Name them.

Answer: Mercury and Venus are the planets which lie between the Sun and the Earth.

Question 33: Which comet was last seen in 1986 after a period of 76 years?

Answer: Halley’s comet, which appears after nearly every 76 years was last seen in 1986.

Question 34: Which planet is known as the red planet and why?

Answer: Mars is known as the red planet because it appears slightly reddish in colour.

Question 35: What do we call the heavenly bodies in the sky which orbit the planets?

Answer: The heavenly bodies in the sky which orbit the planets are called satellites.

Question 36: Which member of the Solar System appears in the sky like a bright ball of light with a long glowing tail?

Answer: A Comet appears in the sky like a bright ball of light with a long glowing tail.

Question 37: Name the constellation which appears to have the shape of a distorted W or M.

Answer: Cassiopeia is the constellation which appears to have the shape of a distorted W or M.

Question 38: Which constellation appears to have the shape of a big ladle or a question mark?

Answer: Ursa Major is the constellation appears to have the shape of a big ladle or a question mark.

Question 39: What are the celestial objects that we can see in the sky?

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

Question 40: What is full moon?

Answer: The day on which the whole disc of the moon is visible is known as the full moon day.

Question 41: Which is the brightest star in the sky?

Answer: The star Sirius is the brightest star in the sky. It is located close to Orion.

Question 42: What are ‘celestial objects’?

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

 Question 43: Which planet has a well-developed system of rings around it?

Answer: Saturn has a well-developed system of rings around it. These rings are not visible with the naked eye.

Question 44: Which star always remains in the same position in the sky in the north?

Answer: The pole star is the star which remains in the same position in the sky in the north.

Question 45: Which unit is used to measure the distance between celestial bodies?

Answer: Light year is the unit used to measure the distance between the various celestial bodies.

Question 46: What causes day and night on earth?

Answer: The change between day and night is caused by the rotation of the Earth on its axis.

Question 47: What time of year is the constellation Orion visible?

Answer: Orion is well-known constellation that can be seen during winter in the late evenings.

Short Answer Type Questions

Question 1: How will our Earth look when seen from a space and why?

Answer: From space, the Earth appears blue-green due to the reflection of light from water and landmass on its surface.

Question 2: What causes the change in seasons?

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.

Question 3: What is meteorite?

Answer: Some meteors are large so that they can reach the Earth before they evaporate completely. The body that reaches the Earth is called a meteorite.

Question 4: Who landed on the moon for the first time?

Answer: On July 21, 1969 (Indian time), the American astronaut Neil Armstrong landed on the moon for the first time followed by Edwin Aldrin.

Question 5: Why are stars not visible during the daytime?

Answer: In fact, the stars are present in the sky during the day-time also. However, they are not visible then because of the bright sunlight.

Question 6: Why the Sun appears to rise in the east and set in the west?

Answer: The Sun appears to rise in the east and set in the west because the Earth rotates from west to east on its axis.

Question 7: Which is the star nearest to the Earth?

Answer: The Sun is the star nearest to the Earth. It is nearly 150,000,000 kilometres (150 million km) away from the Earth.

Question 8: Why does Pole Star appear to be stationary in the sky?

Answer: The pole star appears to be stationary from the Earth, because it is situated close to the direction of the axis of rotation of the Earth.

Question 9: How long does it take sunlight to reach the Earth?

Answer: It takes sunlight an average of 8 minutes and 20 seconds to travel from the Sun to the Earth.

Question 10: What characteristics of Mars distinguish it from other planets?

Answer: Mars appears slightly reddish and, therefore, it is also called the red planet. Mars has two small natural satellites.

Question 11: Which constellation appears like a big ladle or a question mark?

Answer: Ursa Major appears like a big ladle or a question mark. It is also known as the Big Dipper, the Great Bear or the Saptarshi.

Question 12: Which is the nearest star to earth, after the sun?

Answer: Alpha Centauri is the nearest star to earth, after the sun. It is at a distance of about 40,000,000,000,000 km from the Earth.

Question 13: What is a constellation? Name any two constellations.

Answer: The stars forming a group that has a recognisable shape is called a constellation. Two constellations are Ursa Major and Orion.

Question 14: Name the constellation which appears to have the shape of a big bear.

Answer: Ursa Major is the constellation which appears to have the shape of a big bear. It is also known as the Big Dipper, the Great Bear or the Saptarshi.

Question 15: In which part of the sky can you find Venus if it is visible as an evening star?

Answer: Sometimes Venus appears in the western sky just after sunset. Therefore it is often called an evening star, although it is not a star.

Question 16: Which agency is responsible for the development of space science programs in India?

Answer: Indian Space Research Organization (ISRO) is the agency responsible for the development of space science programs in India.

Question 17: What is solar system?

Answer: The Sun and the celestial bodies which revolve around it form the solar system. It consists of large number of bodies such as planets, comets, asteroids and meteors.

Question 18: What is the simplest method of identifying planets from stars?

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

Question 19: What are planets?

Answer: The planets look like stars, but they do not have light of their own. They merely reflect the sunlight that falls on them. A planet has a definite path in which it revolves around the Sun.

Question 20: What are meteors?

Answer: At night, when the sky is clear and the moon is not there, we may sometimes see bright streaks of light in the sky. These are commonly known as shooting stars, although they are not stars. They are called meteors.

Question 21: Which star has a system of planets with life on one of its planets?

Answer: The Sun is the star which has a system of planets with one planet called Earth with life on it. The Earth is the only planet on the solar system on which life is known to exist.

Question 22: What are uses of artificial satellites?

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

Question 23: What are 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. The inner planets have very few moons.

Question 24: What is a Meteor Shower?

Answer: When the Earth crosses the tail of a comet, swarms of meteors are seen. These are known as meteor showers. Some meteor showers occur at regular intervals each year.

Question 25: Why does the Sun appear to be bigger and brighter than all other stars?

Answer: The Sun is the nearest star from us and it is continuously emitting huge amounts of heat and light. Thus, the Sun appear to be bigger and brighter than all other stars.

Question 26: What is an artificial satellite? Name any two artificial satellites launched by India.

Answer: There are many man-made satellites revolving round the Earth. These are called artificial satellites. Artificial satellites launched by India are INSAT, IRS, Kalpana-1, EDUSAT, etc.

Question 27: Why the planets do not collide while revolving around the Sun?

Answer: Planets do not collide while revolving around the Sun because each planet has a definite path in which it revolves around the Sun. This path is called an orbit.

Question 28: Which planet is known as evening and morning star and why?

Answer: 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, although it is not a star.

Question 29: Name the eight planets of the Solar System in the order of their increasing distances from the Sun.

Answer: Our Solar System has eight planets which orbit the sun. In order of distance from the sun they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Question 30: What are asteroids? Where are most of them located?

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. Asteroids can only be seen through large telescopes.

Long Answer Type Questions

Question 1: How do the planets stay in orbit around the sun?

Answer: The Sun and the celestial bodies which revolve around it form the solar system. It consists of large number of bodies such as planets, comets, asteroids and meteors. The gravitational attraction between the Sun and these objects keeps them revolving around it.

Question 2: How long does it take for a full moon to change to new moon?

Answer: The day on which the whole disc of the moon is visible is known as the full moon day. Thereafter every night the size of the bright part of the moon appears to become thinner and thinner. On the fifteenth day the moon is not visible. This day is known as the new moon day.

Question 3: Why Pluto is not considered as a planet anymore?

Answer: Till 2006 there were nine planets in the solar system. Pluto was the farthest planet from the Sun. In 2006, the International Astronomical Union (IAU) adopted a new definition of a planet. Pluto does not fit this definition. It is no longer a planet of the solar system.

Question 4: What are 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. They have a ring system around them. The outer planets have large number of moons.

Question 5: Why does the Moon shine?
Or
If the Moon does not have its own light, how are we able to see the moon?

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

Question 6:  Do all the stars in the sky move? Explain.

Answer: No, all the stars in the sky does not move. The earth rotates on its axis from west to east. Therefore, all the stars in the sky seem to move from east to west. The pole star appears to be stationary from the Earth, because it is situated close to the direction of the axis of rotation of the Earth.

Question 7: What are comets?

Answer: Comets are also members of our solar system. They revolve around the Sun in highly elliptical orbits. However, their period of revolution round the Sun is usually very long. A Comet appears generally as a bright head with a long tail. 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 8: What are some unique characteristics of Saturn?

Answer: Saturn appears yellowish in colour. It has a well-developed system of rings around it. These rings are not visible with the naked eye. We can observe them with a small telescope. It also has a large number of satellites. One interesting thing about Saturn is that it is the least dense among all the planets. Its density is less than that of water.

Question 9: Draw a diagram of Cassiopeia constellation to show the position of main stars in it.

Answer:

Question 10: Draw a diagram to show the position of main stars in Leo Major constellation.

Answer:

Question 11: How is the surface of the moon?

Answer: The moon is a fascinating object for poets and story-tellers. But when astronauts landed on the moon, they found that the moon’s surface is dusty and barren. There are many craters of different sizes. It also has a large number of steep and high mountains. Some of these are as high as the highest mountains on the Earth.

Question 12: What factors make life possible on Earth?

Answer: The Earth is the only planet in the solar system on which life is known to exist. Some special environmental conditions are responsible for the existence and continuation of life on the Earth. 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.

Question 13: What is meant by the phases of the Moon? Why phases of the moon occur?
Or
Why does the moon change its shape every day?

Answer: The various shapes of the bright part of the moon as seen during a month are called phases of the moon. The moon does not produce its own light, whereas the Sun and other stars do. We see the moon because the sunlight falling on it gets reflected towards us. We, therefore, see only that part of the moon, from which the light of the Sun is reflected towards us. This is how phases of the moon occur.

Question 14: Why is it difficult to observe the planet Mercury?

Answer: The planet mercury is nearest to the Sun. It is the smallest planet of our solar system. Because Mercury is very close to the Sun, it is very difficult to observe it, as most of the time it is hidden in the glare of the Sun. However, it can be observed just before sunrise or just after sunset, near the horizon. So it is visible only at places where trees or buildings do not obstruct the view of the horizon.

Question 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?

Answer:

Question 16: 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: The Sun is nearly 150,000,000 kilometres (150 million km) away from the Earth. We cannot read this distance in kilometres conveniently. Some stars are even further away. Thus, such large distances are expressed in another unit known as light year. It means the distance between the star and the Earth is equal to the distance travelled by light in eight years.

1 light year= 9.46 × 10¹² Km. 

Therefore, the star is located 8 × 9.46 × 10¹² Km = 75.68 × 10¹² Km away from the Earth.

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