Beyond Earth – Important Questions and Answers
CBSE Class 6 Science Curiosity based on the chapter Beyond Earth. Includes stars, constellations, Pole Star, Big Dipper, Little Dipper, Orion, Sirius, night sky watching, light pollution, Solar System, Sun, planets, Moon, natural satellites, asteroids, comets, Milky Way Galaxy, Universe, case studies, HOTS questions, diagram-based questions, FAQs, and an interactive quiz.
Short Introduction
The chapter Beyond Earth takes students on a journey from the night sky to the Solar System and beyond. It explains stars, constellations, the Pole Star, night sky watching, the Sun, planets, natural satellites, the Moon, asteroids, comets, the Milky Way Galaxy and the Universe. The chapter also teaches students how humans observe the sky, how ancient people used star patterns for navigation, and how curiosity helps us explore the world beyond Earth.
Chapter Overview
Stars
Stars shine with their own light. The Sun is also a star and is the closest star to Earth.
Constellations
Constellations are defined regions of the sky that often include groups of stars forming patterns.
Pole Star
The Pole Star appears nearly stationary in the North direction and helps locate North in the Northern Hemisphere.
Night Sky Watching
Dark, open and cloudless places away from light pollution are best for observing stars and constellations.
Solar System
The Sun, eight planets, their moons, asteroids and comets together form the Solar System.
Planets
A planet is a large, nearly spherical object that revolves around the Sun.
Moon and Satellites
The Moon is Earth’s natural satellite. It revolves around Earth in about 27 days.
Milky Way and Universe
Our Solar System is part of the Milky Way Galaxy. The Universe contains many galaxies.
Important Concept Flow
Stars shine because they produce their own light.
Ancient travellers and sailors used star patterns to find directions.
The Pole Star helps locate North in the Northern Hemisphere.
Most objects of the Solar System move around the Sun.
The Moon revolves around the Earth and is our nearest neighbour in space.
Our Solar System is part of the Milky Way Galaxy, and the Universe contains many galaxies.
Important Keywords with Meanings
| Keyword | Meaning |
|---|---|
| Star | A celestial object that shines with its own light. |
| Sun | The star closest to Earth and the main source of heat and light for Earth. |
| Constellation | A defined region of the sky that often includes a group of stars appearing to form a pattern. |
| Orion | A famous constellation often represented as a hunter. |
| Canis Major | A constellation that contains Sirius, the brightest star in the night sky. |
| Taurus | A constellation that contains Aldebaran and the Pleiades star group. |
| Sirius | The brightest star in the night sky. |
| Big Dipper | A star pattern in the constellation Ursa Major; known in India as Saptaṛiṣhi. |
| Little Dipper | A star pattern in the constellation Ursa Minor. |
| Pole Star | Also called Polaris or Dhruva tārā; it appears nearly stationary in the North direction. |
| Light pollution | Excessive artificial light at night that reduces visibility of stars. |
| Solar System | The Sun, eight planets, their moons and smaller objects such as asteroids and comets. |
| Planet | A large, nearly spherical object that revolves around the Sun. |
| Revolution | The movement of an object around another object, such as Earth around the Sun. |
| Rotation | The spinning of an object about its own axis. |
| Astronomical unit | A unit approximately equal to the distance between the Sun and Earth. |
| Inner planets | Mercury, Venus, Earth and Mars; smaller planets with solid rocky surfaces. |
| Outer planets | Jupiter, Saturn, Uranus and Neptune; giant planets mostly made of gas and ice. |
| Venus | A planet commonly called the Morning Star or Evening Star, although it is not a star. |
| Mars | The Red Planet because its soil appears reddish. |
| Earth | The Blue Planet because a large part of its surface is covered with water. |
| Dwarf planet | A smaller object such as Pluto that revolves around the Sun but is not classified as a planet. |
| Satellite | An object that moves around a planet or a larger object. |
| Natural satellite | A naturally occurring satellite, such as the Moon. |
| Moon | Earth’s natural satellite and our nearest neighbour in space. |
| Crater | A circular bowl-like structure on the Moon’s surface, usually formed by impacts from space rocks. |
| Asteroid | A rocky, irregularly shaped small object in the Solar System. |
| Asteroid belt | A region between Mars and Jupiter where many asteroids revolve around the Sun. |
| Comet | An icy-rocky object made of dust, gases, rocks and ice, often seen with a long tail near the Sun. |
| Milky Way Galaxy | Our home galaxy, also called Ākāśha Gangā. |
| Galaxy | A huge collection of millions to billions of stars. |
| Universe | The vast space containing galaxies, stars, planets and all celestial objects. |
| Exoplanet | A planet discovered revolving around a star other than the Sun. |
Very Short Answer Questions
1. What is a star?
Answer: A star is a celestial object that shines with its own light.
2. Which star is closest to Earth?
Answer: The Sun is the closest star to Earth.
3. What are constellations?
Answer: Constellations are defined regions of the sky that often include groups of stars forming patterns.
4. How many constellations are officially listed by the IAU?
Answer: 88 constellations.
5. Which constellation is often represented as a hunter?
Answer: Orion.
6. Which is the brightest star in the night sky?
Answer: Sirius.
7. In which constellation is Sirius found?
Answer: Sirius is found in Canis Major.
8. What is the Big Dipper called in India?
Answer: The Big Dipper is known as Saptaṛiṣhi in India.
9. What is the Pole Star called in India?
Answer: The Pole Star is known as Dhruva tārā.
10. What direction does the Pole Star help us locate?
Answer: The Pole Star helps us locate the North direction.
11. What is light pollution?
Answer: Excessive artificial light at night is called light pollution.
12. Which app is mentioned for identifying stars and planets?
Answer: Sky Map and Stellarium are mentioned.
13. What is the Solar System?
Answer: The Sun, eight planets, their moons, asteroids and comets together form the Solar System.
14. What is a planet?
Answer: A planet is a large, nearly spherical object that revolves around the Sun.
15. How many planets are there in the Solar System?
Answer: There are eight planets in the Solar System.
16. Name the first planet from the Sun.
Answer: Mercury.
17. Which planet is called the Red Planet?
Answer: Mars.
18. Which planet is called the Blue Planet?
Answer: Earth.
19. Which planet is called the Morning Star or Evening Star?
Answer: Venus.
20. What is Earth’s natural satellite?
Answer: The Moon.
21. How long does the Moon take to revolve around Earth?
Answer: About 27 days.
22. What are craters?
Answer: Craters are circular bowl-like structures on the Moon’s surface.
23. What are asteroids?
Answer: Asteroids are small rocky and irregularly shaped objects in the Solar System.
24. Where is the asteroid belt located?
Answer: The asteroid belt lies between Mars and Jupiter.
25. What is our home galaxy called?
Answer: Our home galaxy is called the Milky Way Galaxy or Ākāśha Gangā.
Short Answer Questions
1. Why do stars appear bright in the night sky?
Answer: Stars appear bright because they shine with their own light. Some stars appear bright and some appear dim depending on their distance, size and brightness.
2. Why were star patterns useful in ancient times?
Answer: Star patterns helped people recognise stars and find directions. Before modern technology and the magnetic compass, sailors and travellers used stars for navigation at sea and on land.
3. What is the difference between a constellation and a star pattern?
Answer: Earlier, groups of stars forming patterns were called constellations. Now, constellations are defined regions of the sky that often include these star patterns. The star pattern is the visible arrangement of stars inside or near that region.
4. Write two facts about Orion.
Answer: Orion is a constellation often represented as a hunter. It has three bright stars in the middle that are imagined as the belt of the hunter.
5. How can Sirius be located using Orion?
Answer: First identify the three middle stars of Orion. Imagine a straight line passing through these stars and look along the line towards the east. This leads to Sirius.
6. How can the Pole Star be located using the Big Dipper?
Answer: Identify the two stars at the end of the Big Dipper’s cup. Imagine a straight line passing through them towards the north. At about five times the distance between these two stars, the line leads to the Pole Star.
7. Why are fewer stars visible in big cities?
Answer: Fewer stars are visible in big cities due to light pollution, smoke and dust. Tall buildings and trees may also block the view of the sky.
8. What precautions should be taken during night sky watching?
Answer: Night sky watching should be done with adults. Choose a dark open area away from lights, buildings and trees. Avoid unsafe places and allow the eyes about half an hour to adjust to darkness.
9. Why does the Sun appear larger than other stars?
Answer: The Sun appears larger because it is much closer to Earth than other stars. Other stars are very far away, so they look like tiny bright dots.
10. Why are stars not visible during daytime?
Answer: During daytime, the Sun is extremely bright. Its brightness lights up the sky, so other stars cannot be seen from Earth.
11. Why is Venus called the Morning Star or Evening Star?
Answer: Venus is usually seen shining brightly at dawn or dusk, so it is commonly called the Morning Star or Evening Star. However, Venus is a planet, not a star.
12. Why is Mars called the Red Planet?
Answer: Mars is called the Red Planet because its soil is reddish in colour, which makes the planet appear red.
13. Why is Earth called the Blue Planet?
Answer: A large part of Earth’s surface is covered with water. Therefore, Earth appears blue from space and is called the Blue Planet.
14. How can planets be distinguished from stars?
Answer: Stars appear to twinkle a lot, while planets generally do not twinkle as much. Planets shine by reflecting sunlight.
15. What are comets made of?
Answer: Comets are made of dust, gases, rocks and ice. When they come close to the Sun, frozen material evaporates and forms a tail.
Long Answer Questions
1. Explain stars and constellations.
Answer: Stars are celestial objects that shine with their own light. At night, some stars look bright and some look dim. Some groups of stars appear to form patterns like animals, objects or characters. Ancient people gave names and stories to these patterns. These star patterns helped people recognise stars and find directions. Today, constellations are defined regions of the sky. The International Astronomical Union officially listed 88 constellations.
2. Explain the importance of the Pole Star.
Answer: The Pole Star, also called Polaris or Dhruva tārā, appears nearly stationary in the North direction. It is part of the Little Dipper. Since it appears fixed in the North, it helps people locate the North direction in the Northern Hemisphere. It can be found using the Big Dipper by extending an imaginary line through the two stars at the end of the Big Dipper’s cup.
3. Write a note on night sky watching.
Answer: Night sky watching is best done on a clear, cloudless night from a dark open area away from city lights, tall buildings and trees. Light pollution, smoke and dust reduce the number of visible stars. For observing dim stars such as the Pole Star, it is better to choose a night without the Moon and clouds. Sky mapping apps such as Sky Map and Stellarium can help identify stars, constellations and planets. Students should always go with adults for safety.
4. Explain the Sun and its importance.
Answer: The Sun is a star and the closest star to Earth. It is an extremely hot spherical ball of gases. It produces heat and light and is the main source of energy on Earth. Sunlight helps plants grow and prepare food. Plants provide food and oxygen to animals and humans. The Sun is responsible for climate, seasons, weather, water cycle and winds. Life on Earth is possible because of the Sun’s energy.
5. What is the Solar System? Name the planets in correct order.
Answer: The Solar System consists of the Sun, eight planets, their moons and many smaller objects such as asteroids and comets. Most objects in the Solar System move around the Sun. The eight planets in increasing order of distance from the Sun are:
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
6. Differentiate between inner planets and outer planets.
| Inner Planets | Outer Planets |
|---|---|
| Mercury, Venus, Earth and Mars are inner planets. | Jupiter, Saturn, Uranus and Neptune are outer planets. |
| They are closer to the Sun. | They are farther from the Sun. |
| They are smaller in size. | They are much larger in size. |
| They have solid rocky surfaces. | They are mostly made of gas and ice. |
7. Explain the Moon as Earth’s natural satellite.
Answer: The Moon is Earth’s natural satellite. It revolves around Earth in about 27 days. It is our nearest neighbour in space and is about 3,84,000 km away from Earth. The Moon is about one-quarter the diameter of Earth. There is hardly any atmosphere on the Moon. Its surface has circular bowl-like structures called craters, mainly formed due to impacts of asteroids or rocks from space.
8. Explain asteroids and comets.
Answer: Asteroids are small rocky objects in the Solar System. They are irregular in shape and many of them revolve around the Sun between Mars and Jupiter in a region called the asteroid belt. Comets are icy-rocky objects made of dust, gases, rocks and ice. When a comet approaches the Sun, its frozen material starts evaporating and forms a long tail. Halley’s Comet is a famous comet that appears every 76 years.
9. What is the Milky Way Galaxy?
Answer: The Milky Way Galaxy is our home galaxy. It is also called Ākāśha Gangā. On a moonless night from a dark location away from city lights, it may appear as a faint band of light across the sky. A galaxy contains millions to billions of stars. Our Solar System is part of the Milky Way Galaxy.
10. What is the Universe? Is there life beyond Earth?
Answer: The Universe contains galaxies, stars, planets and all celestial objects. There are many galaxies beyond the Milky Way Galaxy. Scientists study them to understand stars, galaxies and the Universe. We do not yet know if life exists elsewhere in the Universe. Scientists are searching for life mostly on exoplanets, which are planets revolving around stars other than the Sun. Till now, no evidence of life elsewhere has been found.
Case-Study Based Questions
Case Study 1: Night Sky in Ladakh
Yangdol and Dorjay live in Nubra, Ladakh. The sky there is almost cloudless and has very little air or light pollution. They can see thousands of stars at night.
Q1. Why are many stars visible from Nubra?
Answer: Because Nubra has clear skies with very little air and light pollution.
Q2. Why are fewer stars visible in cities?
Answer: Due to light pollution, smoke, dust, tall buildings and trees.
Q3. What is the best place for night sky watching?
Answer: A dark open area away from lights, buildings and trees.
Case Study 2: Finding North
A traveller sees the Big Dipper in the northern sky. He uses the two stars at the end of its cup to locate another star that appears almost fixed.
Q1. Which star is he locating?
Answer: The Pole Star or Polaris.
Q2. Which direction does it indicate?
Answer: North direction.
Q3. What is the Big Dipper called in India?
Answer: Saptaṛiṣhi.
Case Study 3: Orion and Sirius
A student observes three bright stars in a short straight line in the middle of a constellation during December after sunset.
Q1. Which constellation is likely being observed?
Answer: Orion.
Q2. What do the three stars represent?
Answer: The belt of the hunter Orion.
Q3. Which bright star can be located near Orion?
Answer: Sirius.
Case Study 4: Planet or Star?
At dusk, a child sees a very bright object near the western direction. It is not twinkling much and looks brighter than nearby stars.
Q1. Which planet may it be?
Answer: Venus.
Q2. Why is Venus often called the Evening Star?
Answer: Because it is seen shining brightly at dusk, although it is a planet, not a star.
Q3. How can planets be distinguished from stars?
Answer: Stars twinkle a lot, while planets generally twinkle much less.
Case Study 5: Moon Surface
A telescope shows circular bowl-like structures on the Moon’s surface. The teacher explains that these structures remain visible for a very long time.
Q1. What are these structures called?
Answer: Craters.
Q2. How were most craters formed?
Answer: By impacts of asteroids or rocks from space hitting the Moon.
Q3. Why do these features stay for a long time?
Answer: Because the Moon has hardly any atmosphere, water or life to erase them quickly.
Assertion-Reason Questions
Choose the correct option:
A. Both Assertion and Reason are true and Reason is the correct explanation.
B. Both Assertion and Reason are true but Reason is not the correct explanation.
C. Assertion is true but Reason is false.
D. Assertion is false but Reason is true.
1. Assertion: Stars shine with their own light. Reason: The Sun is also a star.
Answer: B
2. Assertion: Star patterns were useful for navigation. Reason: They helped sailors and travellers find directions.
Answer: A
3. Assertion: The Pole Star helps locate North. Reason: It appears nearly stationary in the North direction.
Answer: A
4. Assertion: The night sky is best viewed from bright city markets. Reason: Light pollution helps us see dim stars clearly.
Answer: Both Assertion and Reason are false.
5. Assertion: The Sun appears bigger than other stars. Reason: The Sun is much closer to us than other stars.
Answer: A
6. Assertion: Earth is a planet. Reason: Earth revolves around the Sun.
Answer: A
7. Assertion: Venus is called the Morning Star or Evening Star. Reason: Venus is actually a star that produces its own light.
Answer: C
8. Assertion: Mars is called the Red Planet. Reason: The soil on Mars is reddish in colour.
Answer: A
9. Assertion: The Moon is Earth’s natural satellite. Reason: It revolves around Earth.
Answer: A
10. Assertion: Comets may develop long tails near the Sun. Reason: Frozen material in comets starts evaporating near the Sun.
Answer: A
Competency-Based and Critical Thinking / HOTS Questions
1. Why does the Sun look big while other stars look like tiny dots?
Answer: The Sun is much closer to Earth than other stars. Other stars may be very large, but they are extremely far away, so they appear like tiny bright dots.
2. Why is it better to observe the Pole Star on a moonless night?
Answer: The Pole Star is not very bright. Moonlight can make dim stars harder to see, so a moonless night is better for observing it.
3. Why is Venus hotter than Mercury although Mercury is closer to the Sun?
Answer: Venus has an atmosphere that traps heat. This makes Venus hotter than Mercury even though Mercury is closer to the Sun.
4. Why is Pluto not counted among the eight planets?
Answer: After the IAU redefined the requirements for an object to be called a planet in 2006, Pluto and similar smaller objects were classified as dwarf planets.
5. Why can we see the Moon though it does not produce its own light?
Answer: The Moon reflects sunlight from its surface. That reflected light reaches our eyes, so we can see the Moon.
6. Why are craters on the Moon preserved for a very long time?
Answer: The Moon has hardly any atmosphere, water or life. Therefore, wind, rain or living activity do not erase the craters quickly.
7. How can light pollution affect humans and science?
Answer: Light pollution reduces our ability to see and study stars and other sky objects. It also reduces people’s chance to enjoy the natural night sky.
8. Why do planets generally look like stars to the naked eye?
Answer: Planets are very far away from Earth, so they appear as shining dots. However, unlike stars, they shine mainly by reflecting sunlight.
9. Why is the Solar System not the same as the Universe?
Answer: The Solar System is only the Sun, planets and smaller objects around the Sun. The Universe is much larger and contains many galaxies, including the Milky Way Galaxy.
10. Why is the search for life outside Earth mostly directed towards exoplanets?
Answer: Exoplanets are planets revolving around stars other than the Sun. Since planets may provide suitable conditions for life, scientists study exoplanets in the search for life beyond Earth.
Diagram-Based Questions
Diagram 1: Big Dipper to Pole Star
Question: Which star helps locate the North direction?
Answer: The Pole Star.
Diagram 2: Orion and Sirius
Question: Which is the brightest star in the night sky?
Answer: Sirius.
Diagram 3: Order of Planets
Question: Which planet comes after Earth?
Answer: Mars.
Diagram 4: Members of the Solar System
Question: Which is the largest and heaviest object in the Solar System?
Answer: The Sun.
Diagram 5: Beyond Earth
Question: What is our home galaxy called?
Answer: The Milky Way Galaxy or Ākāśha Gangā.
Quick Revision Box
- Stars shine with their own light.
- The Sun is the closest star to Earth.
- Constellations are defined regions of the sky that often include star patterns.
- The IAU officially listed 88 constellations.
- Orion is often represented as a hunter.
- Sirius is the brightest star in the night sky.
- The Big Dipper lies in Ursa Major and is called Saptaṛiṣhi in India.
- The Pole Star is also called Polaris or Dhruva tārā.
- The Pole Star helps locate North in the Northern Hemisphere.
- Light pollution means excessive artificial light at night.
- Dark open places are best for night sky watching.
- The Sun is an extremely hot spherical ball of gases.
- The Sun is about 150 million km away from Earth.
- The Sun is about 100 times bigger than Earth in diameter.
- A planet is a large, nearly spherical object that revolves around the Sun.
- The eight planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
- Mercury, Venus, Earth and Mars are inner rocky planets.
- Jupiter, Saturn, Uranus and Neptune are outer giant planets.
- Venus is called the Morning Star or Evening Star.
- Mars is called the Red Planet.
- Earth is called the Blue Planet.
- The Moon is Earth’s natural satellite.
- The Moon revolves around Earth in about 27 days.
- Asteroids are rocky irregular objects.
- Comets are made of dust, gases, rocks and ice.
- Our Solar System is part of the Milky Way Galaxy.
Important Exam Tips
Interactive Quiz
Choose the correct answer and click submit.
Frequently Asked Questions
1. What is a star?
A star is a celestial object that shines with its own light.
2. What is a constellation?
A constellation is a defined region of the sky that often includes groups of stars appearing to form patterns.
3. Which is the brightest star in the night sky?
Sirius is the brightest star in the night sky.
4. What is the Pole Star?
The Pole Star, or Polaris, appears nearly stationary in the North direction and helps locate North.
5. What is the Solar System?
The Solar System consists of the Sun, eight planets, their moons, asteroids and comets.
6. What are the eight planets in order?
The eight planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
7. Why is Earth called the Blue Planet?
Earth is called the Blue Planet because a large portion of its surface is covered with water, making it appear blue from space.
8. What is the Moon?
The Moon is Earth’s natural satellite and revolves around Earth in about 27 days.
9. What are asteroids?
Asteroids are small rocky and irregularly shaped objects in the Solar System.
10. What is the Milky Way Galaxy?
The Milky Way Galaxy, also called Ākāśha Gangā, is our home galaxy and contains millions to billions of stars.
Final Conclusion
The chapter Beyond Earth helps students understand the night sky, star patterns, constellations, the Sun, planets, the Moon, asteroids, comets, the Milky Way Galaxy and the Universe. It shows that the Sun is our nearest star and the main source of energy, Earth is one of eight planets, the Moon is Earth’s natural satellite, and our Solar System is only a small part of the Milky Way Galaxy. The chapter encourages students to observe, question and explore the universe with curiosity.
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