NCERT Solutions for Class 8 Science Chapter Stars and the Solar System 17 - Free PDF Download
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
Ans: (c) A constellation
A constellation is not a member of the solar system because it is a group of stars forming a definite shape whereas an asteroid, satellite, and comet are a part of the solar system.
2. Which of the following is NOT a planet of the sun?
a) Sirius
b) Mercury
c) Saturn
d) Earth
Ans: (a) Sirius
Sirius is not a planet of the sun but a star. The planets of the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
3. Phases of the moon occur because
a) we can see only that part of the moon that 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.
Ans: (a) we can see only that part of the moon that reflects light towards us.
Phases of the moon occur because the source of light of the moon is the Sun, it does not have its light and hence, it reflects the light coming from the sun and we can only see that part of the moon that reflects light towards us.
4. Fill in the blanks:
a) The planet which is farthest from the sun is _________.
Ans: The planet which is farthest from the sun is Neptune.
b) The planet which appears reddish in colour is _________.
Ans: The planet which appears reddish in color is Mars.
c) A group of stars that appear to form a pattern in the sky is known as a _________.
Ans: 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 _______.
Ans: A celestial body that revolves around a planet is known as a satellite.
e) Shooting stars are actually not _________.
Ans: Shooting stars are actually not stars.
f) Asteroids are found between the orbits of ____ and _____.
Ans: Asteroids are found between the orbits of Mars and Jupiter.
5. Mark the following statement as true (T) or false (F).
a) Pole star is a member of the solar system.
Ans: True
Stars are a member of the solar system.
b) Mercury is the smallest planet in the solar system.
Ans: True
Mercury is the smallest planet and all other planets are larger than mercury.
c) Uranus is the farthest planet in the solar system.
Ans: False
Neptune is the farthest planet in the solar system.
d) INSAT is an artificial satellite.
Ans: True
INSAT is a man-made satellite.
e) There are nine planets in the solar system.
Ans: False
There are eight planets in the solar system. The planets of the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
f) Constellation Orion can be seen only with a telescope.
Ans: False
During winters, the constellation Orion is visible with naked eyes.
6. Match items in column A with one or more items in column B.
Ans: Inner planets are the first four planets closest to the Sun-Mercury, Venus, Earth, and Mars.
Therefore, (i) Inner planets – e) Earth, g) Mars
Outer planets are the last four planets closest to the Sun – Jupiter, Saturn, Uranus, and Neptune
Therefore, (ii) Outer planets – a) Saturn
A constellation is a group of stars forming a definite shape.
Therefore, (iii) Constellation – c) Great Bear, f) Orion
A satellite of the earth is the moon.
Therefore, (iv) Satellite of earth – d) Moon
7. In which part of the sky can you find Venus if it is visible as an evening star?
Ans: The part of the sky where we can find Venus if it is visible as an evening star is the west side of the sky.
8. Name the largest planet of the solar system.
Ans: The largest planet of the solar system is Jupiter and the smallest planet is Mercury.
9. What is a constellation? Name any two constellations.
Ans: A constellation is a group of stars forming a definite shape. The two constellations are:
i) Orion: It is located on the celestial equator and is visible throughout the world. It is a constellation in the night sky.
ii) Great Bear: It is located in the northern sky.
10. Draw sketches to show the relative position of prominent stars in
a) Ursa Major
Ans: Ursa major is located in the northern sky.
The sketch of the Ursa Major is:
b) Orion
Ans: Orion is located on the celestial equator and is visible throughout the world. It is a constellation in the night sky.
The sketch of the Orion is:
(Image Will Be Updated Soon)
11. Name two objects other than planets that are members of the solar system.
Ans: The two other objects other than planets that are members of the solar system are:
i) Stars: Stars are celestial bodies made up of gases; they are huge in size and have very high temperatures
ii) Asteroid: Asteroids are small, rocky objects that orbit the sun.
12. Explain how you can locate the Pole Star with the help of Ursa Major.
Ans: We locate the Pole Star with the help of Ursa Major with the help of the three stars at the end of Ursa Major. To do so, create a straight line passing through the last three stars and extend that line in the north direction. The star seen in that direction is the Pole star.
13. Do all the stars in the sky move? Explain.
Ans: No, the stars in the sky do not move because the Pole star is located above the axis of rotation of the Earth in the north direction. And hence it appears to be stationary and all other stars in the sky appear to move from East to West.
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?
Ans: Stars are very far away from each other and the standard km notation of the distance seems unrealistic to use for denoting the distance between stars and hence, a much convenient and larger unit is used for expressing these distances which are known as light-years. It helps to make calculations and imagination easy.
One light-year denotes the distance traveled by light in one year.
$1\text{ Light Year = 9}\text{.46}\times {{10}^{\text{12}}}\text{ }km$
A star is eight light-years away from the Earth means that a star is $\text{8}\times \text{ 9}\text{.46}\times {{10}^{\text{12}}}=7.568\times {{10}^{\text{13}}}\text{ }km$ 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?
Ans: The shape of Earth and Jupiter is a sphere. Let the radius of Earth be ${{R}_{E}}$ and the radius of Jupiter be ${{R}_{J}}$.
Given, ${{R}_{J}}=11\cdot {{R}_{e}}$ …..(1)
We know that the volume of a sphere of the radius $r$ is $\dfrac{4}{3}\pi {{r}^{3}}$. Therefore,
The volume of Earth, ${{V}_{E}}=\dfrac{4}{3}\pi R_{E}^{3}$ …… (2)
The volume of Jupiter, ${{V}_{J}}=\dfrac{4}{3}\pi R_{J}^{3}$
But from (1), ${{R}_{J}}=11\cdot {{R}_{e}}$. Hence, Volume of Jupiter, ${{V}_{J}}={{\left( 11 \right)}^{3}}\dfrac{4}{3}\pi R_{E}^{3}$ ...(3)
From (2) and (3), the ratio of the volumes of Jupiter and the Earth is
$\dfrac{{{V}_{J}}}{{{V}_{E}}}=\dfrac{{{\left( 11 \right)}^{3}}\dfrac{4}{3}\pi R_{E}^{3}}{\dfrac{4}{3}\pi R_{E}^{3}}$
$\Rightarrow \dfrac{{{V}_{J}}}{{{V}_{E}}}={{\left( 11 \right)}^{3}}$
$\therefore \dfrac{{{V}_{J}}}{{{V}_{E}}}=1331$
This means that Jupiter can accommodate $1331$ earth.
16. Boojho made the following sketch of the solar system. Is the sketch correct? If not, correct it.
Ans: The figure of the solar system is incorrect because
a) The positions of Mars and Venus are interchanged.
b) The positions of Uranus and Neptune are interchanged.
c) The asteroid belt which is between Mars and Jupiter should be present between Jupiter and Saturn.
The correct figure is:
NCERT Solutions for Class 8 Science Chapter 17 - Stars and The Solar System
NCERT Solutions Class 8 Chapter 17 is a click away to get explanations to all sorts of problems a student might face when they have an exam or test ahead. These solutions act as a guide for students. NCERT Solutions explain the entire chapter to students in a systematic manner and contribute to making students conceptually strong. With our learning packages, you will study the topics and its concept with more interest and involvement. NCERT Solutions Class 8 Science Chapter 17 come with important points and act as an instrumental tool for students who want to score more marks in the exam.
NCERT Solutions for Class 8 Science Chapter 17
Chapter-17 Stars And The Solar System
In the curriculum of Class 8 Science, Chapter 17 is Stars and the Solar System. Chapter 17 in the Science textbook takes students to outer space and in the universe where they will get to know about different planets in the solar system, celestial objects like the moon, stars, etc., constellations like Orion, the sun, asteroids, meteors, different planets, comets and artificial satellites.
Our highly qualified subject matter experts have prepared these NCERT Solutions for Class 8 Chapter 17 Science in an efficient manner. Through this, they explain the chapter and its concepts with ease. With these NCERT Solutions in hand, cracking the exam is very easy. Our guide also helps to lay a strong foundation for Science fundamentals.
Class 8 Science Chapter-Wise Marks Weightage
Chapter 17 Stars and the Solar System is a part of the Science curriculum. Many questions of the Science section are formed from this chapter. Going through these NCERT Solutions will help the student score better in their exams. The topics covered in the chapter Stars and the Solar System are:
Ex. 17.1 The Moon
Ex. 17.2 The Stars
Ex. 17.3 Constellations
Ex. 17.4 The Solar System
From a competitive exam point of view, the chapter is important. Be it a civil services exam or any Olympiad exam, NCERT Solutions are integral to students.
Why are NCERT Solutions for Class 8 Science Chapter 17 Important?
Preparing from our NCERT Solutions Class 8 is a great way for students to understand the chapter in less time.
These solutions also help in strategy formation for students to excel in exams.
Here, you can read Chapter 17 of Class 8 Science NCERT Book and get important links.
Highly simplified language is used by our experts to prepare these NCERT Solutions which makes it understandable for students.
Students without any hesitation can rely upon these NCERT answers as most of the questions in the CBSE exam are asked from NCERT textbooks.
Important Points
The practice of gathering data from afar using satellites is known as remote sensing.
The Sun is a star because it constantly emits light and heat. It appears larger than other stars because it is closer to Earth.
Mercury, Venus, Earth, Mars, Jupiter, and Saturn were the planets known to ancient astronomers.
Swarms of meteors are seen when the earth passes through the comet's tail, which is known as a meteor shower.
The Sun is a star because it constantly emits light and heat. It appears larger than other stars because it is closer to Earth.
Asteroids are small rock and metal planets that orbit the Sun, mostly between Mars and Jupiter.
Benefits of Using Vedantu for Class 8 Science Chapter 17 - Stars and the Solar System
Key Features of NCERT Solutions, These solutions are designed to help students achieve proficiency in their studies. They are crafted by experienced educators who excel in teaching class 8 Science. Some of the features include:
Comprehensive explanations for each exercise and questions, promoting a deeper understanding of the subject.
Clear and structured presentation for easy comprehension.
Accurate answers aligned with the curriculum, boosting students' confidence in their knowledge.
Visual aids like diagrams and illustrations to simplify complex concepts.
Additional tips and insights to enhance students' performance.
Chapter summaries for quick revision.
Online accessibility and downloadable resources for flexible study and revision.
Conclusion
The NCERT Solutions for Class 8 science Chapter 17 - Stars and the Solar System, provided by Vedantu, is a valuable tool for Class 8 students. It helps introduce Science concepts in an accessible manner. The provided solutions and explanations simplify complex ideas, making it easier for Class 8 Students to understand the material. By using Vedantu's resources, Students can develop a deeper understanding of NCERT concepts. These solutions are a helpful aid for grade 8 students, empowering them to excel in their studies and develop a genuine appreciation for the chapter “Stars and the Solar System”.
Chapter-wise NCERT Solutions for Class 8 Science
Chapter 17 - Stars and The Solar System
Along with this, students can also view additional study materials provided by Vedantu, for Class 8 :
FAQs on NCERT Solutions for Class 8 Science Chapter 17 - Stars And The Solar System
1. How do you solve the problem calculating the ratio of Jupiter's volume to Earth's in NCERT Class 8 Science Chapter 17?
To solve this, you must follow the correct method as per the CBSE 2025-26 syllabus. First, understand that both planets are considered spheres. The solution involves these steps:
- State the formula for the volume of a sphere: V = (4/3)πr³.
- Use the given information: Jupiter's radius (Rj) is 11 times Earth's radius (Re), so Rj = 11 * Re.
- Write the volumes for both planets: V(Jupiter) = (4/3)π(11Re)³ and V(Earth) = (4/3)πRe³.
- Calculate the ratio V(Jupiter)/V(Earth). The term (4/3)πRe³ cancels out, leaving you with 11³.
- The final ratio is 1331:1, meaning Jupiter can accommodate 1331 Earths.
2. What is the correct method to locate the Pole Star using Ursa Major, as explained in the NCERT textbook?
The correct procedure described in the NCERT solutions for finding the Pole Star involves using the Ursa Major constellation, also known as the Saptarishi or Big Dipper. Imagine a straight line connecting the last two stars at the end of Ursa Major's bowl. If you extend this imaginary line towards the North direction, it will point directly to a bright star that is not very bright. This star is the Pole Star or Dhruva Tara.
3. According to the NCERT solutions, what are the key corrections for the incorrect diagram of the solar system in the textbook exercise?
The provided sketch in the NCERT exercise has several errors. The correct solution requires making the following adjustments to the planetary positions:
- The positions of Venus and Mars must be interchanged. The correct order from the Sun is Mercury, Venus, Earth, Mars.
- The positions of Uranus and Neptune must also be swapped. The correct order is Jupiter, Saturn, Uranus, Neptune.
- The asteroid belt is incorrectly placed. It should be located in the large gap between the orbits of Mars and Jupiter.
4. Why do the phases of the moon occur? How does the NCERT solution explain this phenomenon?
The phases of the moon occur because the moon does not produce its own light. It is a non-luminous body that only reflects sunlight. From Earth, we can only see the part of the moon's surface that is illuminated by the Sun and facing us. As the moon revolves around the Earth, the portion of its sunlit side that is visible to us changes continuously, creating the different phases like the crescent moon, half-moon, and full moon.
5. Why is the distance between stars expressed in light-years and not kilometres?
The distance between stars and other celestial objects is enormous. Using kilometres to measure these vast distances would result in extremely large and inconvenient numbers. Therefore, a much larger and more practical unit, the light-year, is used. A light-year is the total distance that light travels in one year. This unit simplifies calculations and makes it easier to comprehend the immense scale of the universe.
6. Do all the stars in the sky move? Why does the Pole Star appear stationary?
While it appears that stars move from east to west across the sky, this is actually due to the rotation of the Earth on its axis. The stars themselves are relatively fixed in their positions over human lifespans. The Pole Star, however, appears stationary because it is located directly above the Earth's axis of rotation in the northern hemisphere. As the Earth spins, the Pole Star remains in the same spot in the sky, while all other stars appear to revolve around it.
7. What is the fundamental difference between an asteroid and a comet as described in Chapter 17?
The NCERT solutions clarify the key differences. Asteroids are small, rocky, and metallic objects that orbit the Sun, mostly found in the asteroid belt between Mars and Jupiter. They do not have tails. Comets, on the other hand, are made of ice, dust, and rock. As they approach the Sun, the ice vaporises, creating a glowing head (coma) and a long, glowing tail that always points away from the Sun.
8. How does the NCERT solution define a constellation, and which two examples are given as easily recognisable?
A constellation is defined as a group of stars that appear to form a recognisable pattern or shape in the night sky. These patterns have been identified and named by ancient civilisations. The NCERT solutions highlight two major constellations visible from the Northern Hemisphere:
- Ursa Major: Also known as the Great Bear or Saptarishi, it looks like a big ladle or question mark. It is visible in the summer.
- Orion: Also known as the Hunter, it is visible during the winter. It has several bright stars, with three in the middle forming the 'belt'.
9. What is the correct answer for 'Shooting stars are actually not _________' in the fill-in-the-blanks exercise?
The correct answer for the NCERT exercise is that shooting stars are actually not stars. 'Shooting stars' is the common name for meteors. These are small pieces of rock or debris that enter the Earth's atmosphere at very high speed. They burn up due to friction with the air, creating a bright streak of light across the sky.
10. What distinguishes an artificial satellite like INSAT from a natural satellite like the Moon?
The key distinction is their origin. A natural satellite, like the Moon, is a celestial body that naturally orbits a planet. An artificial satellite, like INSAT (Indian National Satellite System), is a man-made object launched into orbit to perform specific tasks such as telecommunication, weather forecasting, and remote sensing. While both revolve around a planet, one is natural and the other is engineered and placed in orbit by humans.
