RBSE Solutions Class 6 Science Chapter 12 Beyond Earth

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Question 1. Which star is closest to us?
Answer: The Sun is the star that is closest to our Earth. This is why it appears so big and bright to us in the sky, much larger than any other star.
In simple words: The Sun is the nearest star to us.

🎯 Exam Tip: Always remember that the Sun is a star, not a planet, and it is the closest one to Earth.

Rbse Class 6th Science Chapter 12 Question Answer - Exercise

Question 2. Match the following:

🎯 Exam Tip: When matching columns, draw lines or write numbers to connect pairs you are sure about first, then fill in the rest.

Question 2. (i) Solve the following riddle.
My first alphabet is in MAN but not in CAN
My second alphabet is in ACE and also in FAN
My third alphabet is in RAT and not in CAT My fourth alphabet is in SUN but not in FUN I am a planet that
Answer:
(ii) (a) My first alphabet is in VAN but not in PAN - V
My second alphabet is in EARTH and also in HEAVEN - E
My third alphabet is in ONE and not in TWO My fourth alphabet is in SUN and also in FUN My last alphabet is in STAR but not in RADAR I am a planet that moves around the Sun. Answer is VENUS.
(b) My first alphabet is in MAN but not in CAN - M
My second alphabet is in ROSE and also in BOAT - O
My third alphabet is in OIL and not in LIME - O
My fourth alphabet is in SUN but not in SON Answer is MOON.
In simple words: This riddle uses clues about letters in words to spell out the names of celestial bodies. Following the clues, the answers are Venus and Moon.

🎯 Exam Tip: For riddles, break down each line and find the letter that fits all conditions. Combine these letters to form the answer.

Question 3. Which of the following is not a member of our Solar System?
(i) Sirius
(ii) Comets
(iii) Asteroids
(iv) Pluto
Answer: (i) Sirius
In simple words: Sirius is a star far away, not part of our Solar System. Comets, asteroids, and Pluto are all part of our Solar System.

🎯 Exam Tip: Understand the difference between stars (like Sirius) and objects within our Solar System (like planets, dwarf planets, comets, and asteroids).

Question 4. Which of the following is not a planet of the Sun?
(i) Jupiter
(ii) Pluto
(iii) Neptune
(iv) Saturn
Answer: (ii) Pluto
In simple words: Pluto is a dwarf planet, not one of the main eight planets that orbit the Sun. Jupiter, Neptune, and Saturn are all main planets.

🎯 Exam Tip: Remember that Pluto was reclassified as a dwarf planet, distinguishing it from the eight major planets.

Question 5. Which is the brighter star, the Pole Star or Sirius?
Answer: Sirius is the brighter star when compared to the Pole Star. Even though the Pole Star is important for navigation, Sirius shines much more brightly in the night sky.
In simple words: Sirius is brighter than the Pole Star.

🎯 Exam Tip: Brightness of a star depends on its actual luminosity and its distance from Earth.

Question. State the correct order of planets from the Sun as shown in Fig. 12.12.
Answer: The planets in their correct order from the Sun are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. The corresponding numeric order is 1, 3, 2, 4, 5, 7, 6, 8. This order is based on their distance, starting from the closest to the Sun.
In simple words: The planets, from closest to furthest from the Sun, are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

🎯 Exam Tip: Memorize the order of the planets from the Sun. A common mnemonic like "My Very Eager Mother Just Served Us Noodles" can help.

Question 7. A portion of night sky with stars is shown in Fig. Look carefully and identify the groups of stars that form the patterns-the Big Dipper and the Little Dipper. Draw lines to connect the stars for these patterns and label them. Also, identify and label the Pole Star. You may refer to Fig. for help.
Answer: The image below shows how to connect the stars to form the patterns of the Big Dipper and the Little Dipper, and also identifies the Pole Star. The Big Dipper has a bowl and a handle, while the Little Dipper is smaller and also has a bowl and a handle, with the Pole Star at the end of its handle.
In simple words: The Big Dipper looks like a large spoon, and the Little Dipper looks like a smaller spoon. The last star in the handle of the Little Dipper is the Pole Star, which stays in the same place in the sky.

🎯 Exam Tip: Practice identifying these constellations in the night sky. The two stars at the end of the Big Dipper's bowl point directly to the Pole Star.

Question 8. A portion of the night sky is shown in Fig. Draw lines to connect the stars for Orion and label the star Sirius. You may refer to Fig. for help.
Answer: The figure below shows the constellation Orion with its characteristic belt of three stars, and Sirius, which is one of the brightest stars in the night sky, located near Orion.
Major Taurus
In simple words: Orion looks like a hunter with a belt of three bright stars in the middle. Sirius, a very bright star, can be found close to Orion.

🎯 Exam Tip: Orion is one of the easiest constellations to spot due to its bright "belt" stars. Sirius, being the brightest star, is also easy to find by looking near Orion.

Question 9. You can see stars fading away at dawn and appearing at dusk. During the day we do not see the stars. Explain, why?
Answer: During the day, we cannot see other stars because the Sun's light is too bright. The Sun's rays scatter in our atmosphere, making the sky appear blue and hiding the much fainter glow of distant stars. It's like a bright light making small lights invisible.
In simple words: The Sun's bright light during the day makes it impossible for us to see the much dimmer stars in the sky.

🎯 Exam Tip: Understand that stars are always in the sky, but their light is overpowered by the Sun's brightness and scattered sunlight in the atmosphere during the day.

Multiple Choice Questions

Question 1. The brightest star in the night sky is-
(a) Pole Star
(b) Orion
(c) Sirius
(d) Taurus
Answer: (c) Sirius
In simple words: Sirius is the brightest star we can see in the night sky.

🎯 Exam Tip: Knowing the brightest stars helps with general astronomy knowledge. Sirius is known for its intense brightness.

Question 2. The entire sky has been divided into how many constellation regions-
(a) 78
(b) 18
(c) 36
(d) 88
Answer: (d) 88
In simple words: The International Astronomical Union has officially divided the whole sky into 88 separate areas, each called a constellation.

🎯 Exam Tip: Remember that constellations are not just star patterns, but defined regions of the sky used by astronomers.

Question 3. Which star is known as Saptarishi in India?
(a) Big Dipper
(b) Little Dipper
(c) Aldebaran
(d) Pleiades
Answer: (a) Big Dipper
In simple words: In India, the Big Dipper constellation is commonly known as Saptarishi.

🎯 Exam Tip: Be aware of different cultural names for common constellations, especially those prominent in Indian astronomy.

Question 4. The Pole Star is a part of which constellation?
(a) Big Dipper
(b) Little Dipper
Answer: (b) Little Dipper
In simple words: The Pole Star, also known as Polaris, is found at the end of the handle of the Little Dipper constellation.

🎯 Exam Tip: The Pole Star's position in the Little Dipper makes it easy to locate, as it remains almost stationary in the northern sky.

Question 5. Which of the following is not an inner planet?
(a) Venus
(b) Earth
(c) Saturn
(d) Mars
Answer: (c) Saturn
In simple words: Saturn is an outer planet, not an inner planet. The inner planets are Mercury, Venus, Earth, and Mars.

🎯 Exam Tip: Know the division of planets into inner (rocky) and outer (gas giants) for quick identification.

Question 6. Is called 'Dwarf Planet'-
(a) Venus
(b) Mercury
(c) Uranus
(d) Pluto
Answer: (d) Pluto
In simple words: Pluto is classified as a dwarf planet because it does not clear its orbit of other objects.

🎯 Exam Tip: Understand the criteria for a dwarf planet, which includes orbiting the Sun, being nearly round, but not clearing its orbital path.

Question 7. How many moons does Mars have-
(a) One
(b) Two
(c) Three
(d) Many
Answer: (b) Two
In simple words: Mars has two small moons orbiting it.

🎯 Exam Tip: Remember that not all planets have many moons; some, like Mars, have only a few or none at all (like Mercury and Venus).

Question 8. How many days does the Moon take to complete one revolution around the Earth-
(a) 27
(b) 24
(c) 30
(d) 26
Answer: (a) 27
In simple words: The Moon takes about 27 days to travel once around the Earth.

🎯 Exam Tip: The Moon's orbital period is approximately 27.3 days, which is also roughly its rotation period, leading to one side always facing Earth.

Question 10. When is National Space Day celebrated-
(a) 28 September
(b) 23 August
(c) 14 November
(d) 16 July
Answer: (b) 23 August
In simple words: National Space Day is celebrated on August 23rd each year.

🎯 Exam Tip: Keep up-to-date with important national and international science dates.

Fill In The Blanks

Question 1. The night sky is best viewed from ............... and ............... areas.
Answer: The night sky is best viewed from **open** and **dark** areas. For clear viewing, it's important to be away from city lights.
In simple words: You see stars best in open, dark places.

🎯 Exam Tip: To get the best view of the night sky, avoid light pollution and choose locations with clear, wide views.

Question 2. The Sun is about ............... times bigger than the Earth in diameter.
Answer: The Sun is about **100** times bigger than the Earth in diameter. This shows how massive and large the Sun truly is compared to our planet.
In simple words: The Sun is 100 times wider than Earth.

🎯 Exam Tip: Understand the scale of the Sun compared to Earth; its huge size explains its gravitational dominance in the solar system.

Question 3. The movement of an object around the Sun is called ............... .
Answer: The movement of an object around the Sun is called **revolution**. This is the orbital motion that planets and other celestial bodies undertake.
In simple words: Moving around the Sun is called revolution.

🎯 Exam Tip: Differentiate between 'revolution' (orbiting around another body) and 'rotation' (spinning on its own axis).

Question 4. ............... are natural satellites of planets.
Answer: **Moons** are natural satellites of planets. They are celestial bodies that orbit planets.
In simple words: Moons are planets' natural helpers.

🎯 Exam Tip: Remember that while Earth has only one Moon, other planets can have many natural satellites.

Question 5. The Sun is a star which produces ............... and ............... .
Answer: The Sun is a star which produces **heat** and **light**. These two forms of energy are crucial for life on Earth.
In simple words: The Sun is a star that gives off heat and light.

🎯 Exam Tip: Understand that the Sun generates its own heat and light through nuclear fusion, unlike planets which reflect light.

Question 1. The constellation Orion is often depicted as a hunter. (True/False)
Answer: True. Orion is commonly seen as a hunter figure in the night sky, a widespread cultural representation.
In simple words: It is true that Orion looks like a hunter.

🎯 Exam Tip: Many constellations have mythological or cultural figures associated with them that help in their recognition.

Question 2. Light pollution is decreasing globally. (True/False)
Answer: False. Light pollution is actually increasing globally, making it harder to observe the night sky in many areas.
In simple words: It is false; light pollution is getting worse, not better.

🎯 Exam Tip: Be aware of environmental issues like light pollution and their impact on scientific observation and natural ecosystems.

Question 3. While revolving around the Sun, the Earth is also rotating about its axis. (True/False)
Answer: True. The Earth both orbits the Sun (revolves) and spins on its own axis (rotates) at the same time, causing years and days respectively.
In simple words: It is true; Earth spins and also travels around the Sun.

🎯 Exam Tip: Remember that Earth's rotation causes day and night, while its revolution around the Sun causes the change in seasons.

Question 4. The sizes of asteroids are from 10 m to about 500 km. (True/False)
Answer: True. Asteroids vary widely in size, from small rocks just a few meters across to much larger bodies hundreds of kilometers in diameter. This statement accurately reflects their size range.
In simple words: It is true; asteroids can be as small as 10 meters or as big as 500 kilometers.

🎯 Exam Tip: Understand that asteroids are diverse in size and composition, and they are mostly found in the asteroid belt between Mars and Jupiter.

Match The Words Given In Column-I With Column-II

🎯 Exam Tip: Understanding the connection between Indian and Western astronomical terms for stars and constellations is important.

Question 2. Match the following:

🎯 Exam Tip: Learn the common names and classifications of various celestial objects to accurately match them.

Very Short Answer Type Questions

Question 2. The diameter of the Sun is about 100 times larger than that of the Earth, yet why does it appear so small to us?
Answer: Even though the Sun is about 100 times wider than Earth, it appears small to us because it is very, very far away. Objects look smaller the further they are from us. This vast distance makes its immense size seem manageable from Earth.
In simple words: The Sun looks small because it is very far from Earth.

🎯 Exam Tip: Remember the inverse relationship between an object's perceived size and its distance from the observer.

Question 3. Which is the closest star to us after the Sun?
Answer: The closest star to us after our Sun is Proxima Centauri. It is extremely far, roughly 269,000 times the distance from Earth to the Sun. This star is part of a three-star system called Alpha Centauri.
In simple words: Proxima Centauri is the closest star after the Sun.

🎯 Exam Tip: Know that Proxima Centauri is part of the Alpha Centauri system and is the nearest star beyond our Solar System.

Question 4. What is called a 'planet'?
Answer: A planet is a large, nearly round object that orbits the Sun. It must also have cleared its orbital path of other debris, distinguishing it from dwarf planets. Planets are typically massive enough for their own gravity to pull them into a spherical shape.
In simple words: A planet is a big, round object that circles the Sun and has a clear path.

🎯 Exam Tip: Remember the three main criteria for a celestial body to be classified as a planet: it must orbit the Sun, be massive enough to be nearly round, and have cleared its orbital neighborhood.

Question 5. From where do planets get their energy?
Answer: Planets get almost all their energy from the Sun. The Sun emits light and heat, which are absorbed by the planets, providing warmth and powering atmospheric processes.
In simple words: Planets get most of their energy from the Sun.

🎯 Exam Tip: Understand that the Sun is the primary source of energy for most processes in our Solar System, including a planet's temperature.

Question 6. Which planet is the easiest to identify and why?
Answer: Venus is the easiest planet to identify because it is very bright. Its thick atmosphere reflects a lot of sunlight, making it stand out in the sky, often visible in the morning or evening. This makes it easily distinguishable from stars.
In simple words: Venus is the easiest planet to spot because it is very bright.

🎯 Exam Tip: Venus is known as both the "Morning Star" and "Evening Star" due to its brightness and visibility at dawn and dusk.

Question 7. Which planets can be seen without the help of any optical instrument?
Answer: Venus, Mercury, Mars, Jupiter, and Saturn can all be seen without the need for a telescope or binoculars. They are bright enough to be visible to the naked eye under clear sky conditions.
In simple words: You can see Venus, Mercury, Mars, Jupiter, and Saturn without a telescope.

🎯 Exam Tip: These five planets have been observed since ancient times because of their naked-eye visibility, unlike Uranus and Neptune which require optical aid.

Question 9. How far is the moon from the earth?
Answer: The Moon is approximately 384,000 kilometers away from the Earth. This distance can vary slightly as the Moon's orbit is not perfectly circular.
In simple words: The Moon is about 384,000 kilometers from Earth.

🎯 Exam Tip: Knowing the approximate distance to the Moon helps in understanding its orbital dynamics and apparent size in the sky.

Question 10. What do you know about Halley's Comet?
Answer: Halley's Comet is a very famous comet that appears in our sky roughly every 76 years. Its last appearance was in 1986, making its next expected visit around 2061. It is a periodic comet, meaning it returns regularly.
In simple words: Halley's Comet is a famous comet that shows up every 76 years. It was last seen in 1986.

🎯 Exam Tip: Halley's Comet is a well-known example of a periodic comet with a predictable return schedule.

Question 11. What is beyond the Milky Way galaxy?
Answer: Beyond our Milky Way galaxy, there are countless other galaxies in the vast expanse of outer space. Our galaxy is just one of billions in the observable universe. These other galaxies contain billions of stars, planets, and other celestial bodies.
In simple words: Outside the Milky Way galaxy, there are many, many other galaxies.

🎯 Exam Tip: Understand that the universe is made up of numerous galaxies, and our Milky Way is just one among them, often grouped into larger structures called galaxy clusters.

Question 12. What is the best time to see the Saptarishi?
Answer: The best time to see the Saptarishi constellation (Big Dipper) is usually around 9 pm during the summer months. During summer evenings, it is high in the northern sky and clearly visible. Its position changes slightly with seasons.
In simple words: You can best see Saptarishi in summer, around 9 at night.

🎯 Exam Tip: Seasonal and time-of-night observations are important for locating specific constellations in the sky.

Question 13. By whose light do the stars shine?
Answer: Stars shine by their own light. They produce light and heat through nuclear reactions happening in their core, which is what makes them luminous. Unlike planets, they do not simply reflect light.
In simple words: Stars make their own light.

🎯 Exam Tip: Distinguish between stars (which generate their own light) and planets (which reflect light from a star).

Question 14. When can Orion be seen best in India?
Answer: In India, the Orion constellation can be seen best in the months from December to April, typically after sunset. During these months, it is prominent in the night sky, making it easy to spot.
In simple words: Orion is best seen in India from December to April after sunset.

🎯 Exam Tip: Knowing the optimal viewing seasons and times for constellations helps in practical stargazing.

Question 15. How big is the moon in comparison to the earth?
Answer: The Moon is about a quarter (one-fourth) the size of Earth in diameter. This means Earth is four times wider than the Moon. Despite its relatively small size, it plays a vital role in Earth's tides.
In simple words: The Moon is about one-fourth the size of Earth.

🎯 Exam Tip: Remember the relative size of the Moon to Earth; it's quite large for a natural satellite compared to its parent planet.

Question 17. What is called 'Solar System'?
Answer: The Solar System is made up of the Sun, the eight planets, their moons, and many smaller objects such as asteroids and comets. All these celestial bodies are gravitationally bound to the Sun. Our Solar System is a small part of the vast Milky Way galaxy.
In simple words: The Solar System includes the Sun, all the planets and their moons, and other small space objects like asteroids and comets.

🎯 Exam Tip: Make sure to include all key components (Sun, planets, moons, asteroids, comets) when defining the Solar System.

Short Answer Type Questions

Question 1. What is nakshatral Explain.
Answer: In Indian astronomy, a "nakshatra" refers to a specific star or a group of stars. For example, Ardra is the star Betelgeuse in the Orion constellation, Krittika is the Pleiades star cluster in the Taurus constellation, and Rohini is the star Aldebaran, also in Taurus. Nakshatras are used in traditional Indian calendars and astrology, often associated with lunar mansions.
In simple words: A nakshatra is an Indian name for a special star or group of stars, like Ardra or Krittika.

🎯 Exam Tip: When explaining 'nakshatra', provide examples of specific stars or groups of stars to illustrate the concept clearly.

Question 2. What do you mean by Big Dipper and Little Dipper?
Answer: The Big Dipper is a well-known star pattern found within the Ursa Major constellation. In India, it is called Saptarishi. The Little Dipper is a smaller pattern located in the Ursa Minor constellation, and its handle ends with the Pole Star (Dhruva Tara). Both are useful for finding directions in the northern sky. The Big Dipper's two "pointer" stars can guide you to the Pole Star.
In simple words: The Big Dipper (Saptarishi) is a large star pattern in Ursa Major, and the Little Dipper is a smaller one in Ursa Minor that contains the Pole Star.

🎯 Exam Tip: Distinguish between the Big Dipper and Little Dipper by their size and their associated constellations (Ursa Major and Ursa Minor, respectively), and remember that the Pole Star is part of the Little Dipper.

Question 3. What are the stories of Indian tribal and forest dwellers about the stars in constellations?
Answer: Many Indian tribal and forest communities have their own unique stories about stars and constellations, separate from common regional tales. For instance, some Central Indian tribes see the four stars forming the rectangle of the Big Dipper as a "grandmother's cot," with the other three stars being "thieves" stealing it. Fishermen on the Konkan coast imagine these four stars as a boat, with the last three stars as the neck of the boat, reflecting their daily lives and connection to the sea. These stories are passed down through generations.
In simple words: Indian tribes tell unique stories about star patterns; for example, some see the Big Dipper as a grandmother's cot being stolen, or as a fishing boat.

🎯 Exam Tip: When asked about cultural stories, provide specific examples to make your answer more detailed and interesting, showing the diversity of human interpretation of the night sky.

Question 5. What will you do to know in which part of the sky and when a constellation will be visible according to your position?
Answer: To find out which constellation is visible and when, we can use special sky map apps on our phones. These apps, like Sky Map or Stellarium, help us find constellations and are free to download. They show us where to look in the night sky, often in real-time.
In simple words: We can use mobile apps like Sky Map to find constellations. These apps show where and when to look for them.

🎯 Exam Tip: To score full marks, mention using technology (apps) as a modern way to locate constellations.

Question 6. What is Astronomical Unit (au)?
Answer: An Astronomical Unit (au) is a special way to measure distances in our solar system. It is roughly the distance from the Sun to the Earth, which is about 150 million kilometers. This unit makes it easier to talk about very large distances in space, preventing huge numbers.
In simple words: An Astronomical Unit (au) is a unit of distance. It is equal to the distance between the Sun and the Earth, which is about 150 million kilometers.

🎯 Exam Tip: Define 'Astronomical Unit' clearly and state its approximate value or what it represents.

Question 7. How is it that the Sun appears big to us while other stars appear like bright points in the night sky and they are not even visible during the day?
Answer: The Sun looks big to us because it is very close to Earth compared to other stars. Other stars are much, much farther away, so they look like tiny bright dots, even if some are actually bigger than our Sun. During the day, the Sun is so bright that its light spreads in our atmosphere, making the sky blue and hiding the fainter light of other stars, a phenomenon known as atmospheric scattering.
In simple words: The Sun looks big because it is close. Other stars are far, so they look tiny. During the day, the Sun's bright light makes them invisible.

🎯 Exam Tip: Explain both reasons: distance for apparent size, and the Sun's brightness (with atmospheric scattering) for daytime invisibility.

Question 8. What do you mean by a day of the Earth?
Answer: A day on Earth is the time it takes for our planet to spin around once on its own axis. This rotation causes day and night. It usually lasts about 24 hours, forming the basis of our timekeeping.
In simple words: An Earth day is how long it takes for our planet to spin once. This gives us day and night, lasting about 24 hours.

🎯 Exam Tip: Define 'day' in terms of Earth's rotation and mention its duration.

Question 9. How can we observe objects in the sky, and what instruments help us?
Answer: Many sky objects can be seen with just our eyes. But to see them brighter and bigger, or to see faint objects we can't see normally, we use binoculars or a telescope. Telescopes especially help us observe many dim things in space that our eyes alone cannot spot, revealing details invisible to the naked eye.
In simple words: We can see some sky objects with our eyes. Binoculars and telescopes help us see them brighter, bigger, and also reveal faint objects we can't see otherwise.

🎯 Exam Tip: When describing observation, mention both naked-eye viewing and the role of optical instruments like binoculars and telescopes.

Question 10. What are natural satellites? Explain.
Answer: Natural satellites are objects that orbit around planets. They are usually smaller than the planets they circle. For example, moons are natural satellites. Earth has one Moon, Mars has two, and big planets like Jupiter, Saturn, Uranus, and Neptune have many moons orbiting them, some even larger than Mercury.
In simple words: Natural satellites are objects that go around planets. Moons are an example. Earth has one, and other planets have more.

🎯 Exam Tip: Define natural satellites, mention their relationship to planets, and give examples like Earth's Moon.

Question 11. What do you mean by Asteroids and asteroid belt?
Answer: Asteroids are small, rocky objects found in our Solar System, and they often have uneven shapes. The asteroid belt is a special region in space located between the orbits of Mars and Jupiter. In this belt, many of these asteroids orbit the Sun together, acting as a boundary between the inner and outer planets.
In simple words: Asteroids are small, rocky space objects, often oddly shaped. The asteroid belt is an area between Mars and Jupiter where many asteroids orbit the Sun.

🎯 Exam Tip: Clearly define asteroids (rocky, irregular) and the asteroid belt (location, what it contains).

Question 12. Is there life anywhere else in the Universe?
Answer: Currently, we don't know for sure if there is life anywhere else in the Universe. Scientists are actively searching, especially by looking at 'exoplanets', which are planets orbiting stars outside our own Solar System. So far, no direct proof of life has been found, but the search continues with new technologies like the James Webb Space Telescope.
In simple words: We don't know if life exists outside Earth. Scientists are looking for it, mainly on planets around other stars, but haven't found any proof yet.

🎯 Exam Tip: State that the existence of extraterrestrial life is unknown but that scientists are actively searching, especially on exoplanets.

Long Answer Type Questions

Question 1. Do we find patterns among the stars just for fun or is there some use of these patterns?
Answer: People long ago enjoyed watching stars and found patterns among them. These patterns were not just for fun; they helped sailors and travelers find their way on both land and sea. Even today, these star patterns can still be used as a backup way to find directions if other methods fail, illustrating the enduring practicality of celestial navigation.
In simple words: Star patterns were not just for fun. Long ago, they helped sailors and travelers find directions. Even now, they can be used as a backup way to navigate.

🎯 Exam Tip: Emphasize the practical uses of star patterns for navigation and time-keeping, both historically and as a backup.

Question 2. What are constellations? How are the constellation boundaries set?
Answer: Constellations were originally groups of stars that formed recognizable patterns. Today, a constellation officially refers to a specific region of the sky that contains one of these star patterns. Because different cultures had their own ways of drawing these patterns, the International Astronomical Union (IAU) set clear, agreed-upon boundaries in the early 20th century. They officially listed 88 constellations, dividing the entire sky into 88 distinct areas, each considered a constellation, ensuring a consistent map for astronomers worldwide.
In simple words: Constellations are star patterns in specific sky regions. Long ago, cultures drew them differently. So, the International Astronomical Union (IAU) officially set 88 constellation boundaries, dividing the whole sky.

🎯 Exam Tip: Define constellations, mention their historical context, and then explain the role of the IAU in standardizing the 88 constellation boundaries.

Question 3. Describe the constellation Orion.
Answer: The constellation Orion is usually seen as a mighty hunter in the night sky. It has three bright stars close together in the middle, which form what looks like the hunter's belt. Many people imagine Orion, with his loyal hunting dog (the constellation Canis Major) by his side, fighting against a bull (the constellation Taurus), a dramatic scene visible to observers.
In simple words: Orion is a constellation shaped like a hunter. Three stars form its belt. People imagine Orion and his dog (Canis Major) fighting a bull (Taurus).

🎯 Exam Tip: Mention Orion's appearance (hunter), key features (belt of three stars), and its mythological association with other constellations like Canis Major and Taurus.

Question 4. What is light pollution? How does it effects the night sky watching?
Answer: Light pollution is when too much artificial light is used at night. This is a growing problem worldwide. It makes it harder for us to see and study stars and other objects in the night sky. To help with this, special "dark sky reserves" have been created where light is controlled so that the night sky remains dark enough for stargazing and research, protecting our view of the cosmos.
In simple words: Light pollution is too much man-made light at night. It stops us from seeing stars well. Dark sky reserves protect night skies, and groups teach how to reduce light pollution.

🎯 Exam Tip: Define light pollution, explain its negative effect on night sky observation, and mention solutions like dark sky reserves and public awareness campaigns.

Question 5. In most ancient civilizations why the Sun is given the status of a deity?
Answer: In many ancient civilizations, the Sun was seen as a god because it is essential for life on Earth. Sunlight helps plants grow, which then provides food and oxygen for animals and people. The Sun also controls our climate, seasons, weather, the water cycle, and winds. All these things are vital for life, so ancient people revered the Sun as a powerful, life-giving deity, often incorporating it into their myths and calendars.
In simple words: Ancient people worshipped the Sun as a god because it brings light, warmth, and makes life on Earth possible. It helps plants grow and controls our weather.

🎯 Exam Tip: Connect the Sun's life-sustaining properties (light, warmth, food chain, climate control) to its deification in ancient cultures.

Question 6. What do you mean by inner and outer planets? Explain.
Answer: Our Solar System has eight main planets. They are divided into two groups: inner planets and outer planets.
(i) Inner Planets: These are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. They are smaller in size and have solid, rocky surfaces, making them terrestrial.
(ii) Outer Planets: These are the four planets farther from the Sun: Jupiter, Saturn, Uranus, and Neptune. They are much larger than Earth and are mostly made of gases. These gas giants often have prominent ring systems made of dust and ice, presenting a stark contrast to their inner counterparts.
In simple words: Inner planets (Mercury, Venus, Earth, Mars) are close to the Sun, small, and rocky. Outer planets (Jupiter, Saturn, Uranus, Neptune) are far from the Sun, big, and made of gas, often with rings.

🎯 Exam Tip: Clearly define and list both inner and outer planets, highlighting their key differences in size, composition (rocky vs. gaseous), and location relative to the Sun.

Question 7. Why Venus is hotter than Mercury, although it is farther from the Sun?
Answer: Even though Venus is farther from the Sun than Mercury, it is hotter. This happens because Venus has a very thick atmosphere, mainly made of carbon dioxide. This dense atmosphere acts like a blanket, trapping a lot of the Sun's heat, a process called the greenhouse effect, making its surface temperature incredibly high.
In simple words: Venus is hotter than Mercury because of its thick atmosphere. This atmosphere traps a lot of heat, making Venus hotter even though it is further from the Sun.

🎯 Exam Tip: Explain that while distance from the Sun generally affects temperature, the greenhouse effect caused by a thick atmosphere (like Venus's) can significantly increase a planet's temperature.

Question 8. What are Dwarf Planet? Explain.
Answer: A dwarf planet is a celestial body that orbits the Sun and is large enough to be rounded by its own gravity, just like a regular planet. However, unlike a true planet, a dwarf planet has not cleared its orbital path of other smaller objects. Pluto is a well-known example. It was once considered a full planet but was reclassified as a dwarf planet by the International Astronomical Union (IAU) in 2006 when similar small objects were found, leading to a new, stricter definition for planets.
In simple words: A dwarf planet orbits the Sun and is round, but it has not cleared its path around the Sun. Pluto is a dwarf planet; it was reclassified in 2006.

🎯 Exam Tip: Define dwarf planets by mentioning they orbit the Sun, are nearly spherical, but have not cleared their orbital neighborhood. Cite Pluto as the primary example and mention the IAU's role.

Essay Type Questions

Question 1. Write a short note on the following :
(i) Sun (ii) Morning Star (iii) Red Planet (iv) Blue Planet
Answer:
(i) Sun: The Sun is a star, and it is the closest star to Earth. It is a giant, extremely hot ball of gases that produces a huge amount of energy, causing it to shine very brightly. The Sun provides all the heat and light that is essential for life on Earth, driving most ecological processes.
(ii) Morning Star: This is another name for the planet Venus. Venus is often seen shining brightly in the sky either at dawn (morning) or dusk (evening), which is why it gets these names. It is important to remember that Venus is a planet, not a star, and its brightness is due to its reflective clouds.
(iii) Red Planet: Mars is known as the Red Planet. Its reddish appearance comes from the iron-rich dust and rocks on its surface, which give its soil a distinctive red color, clearly visible even with small telescopes.
(iv) Blue Planet: Earth is called the Blue Planet. This is because a large part of its surface is covered by water, making it look blue when viewed from space. The presence of liquid water makes Earth unique in our solar system.
In simple words:
(i) The Sun is our closest star, a hot gas ball that gives Earth all its heat and light.
(ii) The Morning Star is actually Venus, a bright planet seen at dawn or dusk, not a real star.
(iii) Mars is the Red Planet because its soil has a reddish color due to iron.
(iv) Earth is the Blue Planet because much of its surface is covered by water.

🎯 Exam Tip: For each part, provide a clear definition or description and explain the reason for its name or key characteristic. Ensure to distinguish between stars and planets.

Question 2. Write a note on : (i) Moon (ii) Comet
Answer:
(i) Moon: The Moon is Earth's only natural satellite and our closest neighbor in space. It has a very thin atmosphere, unlike Earth. The Moon's diameter is about one-fourth the size of Earth's, making it a significant celestial body relative to its parent planet. Its gravity is much weaker, resulting in unique surface features like craters and maria.
(ii) Comet: Comets are icy, rocky objects in space. They are often called "dirty snowballs." As a comet gets close to the Sun, the ice heats up and turns into gas, creating a bright head and a long, glowing tail of gas and dust. These tails always point away from the Sun due to solar wind, making them spectacular sights. When comets move away from the Sun, they cool down and their tails disappear, making them hard to see without a telescope.
In simple words:
(i) The Moon is Earth's natural satellite, very close to us, with almost no air and about a quarter the size of Earth. It has craters on its surface.
(ii) Comets are icy rocks. When they get near the Sun, their ice turns to gas, forming a bright head and a long tail. Tails point away from the Sun.

🎯 Exam Tip: For the Moon, describe its nature as a satellite, atmosphere, size, and surface features. For a comet, explain its composition, how its tail forms near the Sun, and its appearance changes with distance from the Sun.

Question 3. Explain the Chandrayaan mission of India.
Answer: India's Chandrayaan missions are space projects aimed at studying the Moon. Chandrayaan-1 was launched in 2008, followed by Chandrayaan-2 in 2019. The most recent, Chandrayaan-3, successfully landed its Vikram lander and Pragyan rover near the Moon's south pole on August 23, 2023. This achievement made India the first country to successfully land near that unexplored region, showcasing advanced engineering capabilities. To celebrate this historic success, August 23 is now observed as 'National Space Day' in India. Plans are also underway for Chandrayaan-4, which aims to collect and return lunar soil and rock samples to Earth, continuing India's lunar exploration.
In simple words: India's Chandrayaan missions study the Moon. Chandrayaan-3 landed a rover near the Moon's south pole in 2023, making India the first to do so. August 23 is now 'National Space Day'. More missions are planned.

🎯 Exam Tip: Mention the purpose of the Chandrayaan missions, key launches (especially Chandrayaan-3 with its date and achievement), and the declaration of National Space Day.

Rbse Class 6 Science Chapter 12 Notes

Class 6 Science Chapter 12 Notes Rbse - Beyond Earth Class 6 Notes

• Those parts of the sky in which groups of stars are found are called constellations.
• In Indian astronomy, the term nakshatra is used to denote either a certain star or a group of stars.
• The Pole Star appears stationary in the North direction, which helps to locate the North direction in the Northern hemisphere.
• The night sky is best viewed from open dark areas.
• The Sun is our nearest star. The Sun produces heat and light, and is the main source of energy on the Earth.
• A planet is a large, nearly spherical object that revolves around the Sun.
• The eight planets, in order of their increasing distance from the Sun, are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
• Venus is called the Morning Star or the Evening Star. Mars is called the Red Planet, Earth is also called the Blue Planet.
• Our Solar System is part of the Milky Way Galaxy.