Class 6 Science Chapter 12 Beyond Earth Notes & Summary in English for CBSE students
CBSE Class 6 Science Chapter 12 Notes & Summary in English for “Beyond Earth” (based on NCERT textbook Curiosity ).
Chapter 12 – Beyond Earth Complete Notes
(Complete Notes + Concept-wise Explanation + Summary CBSE Class 6 Science – Curiosity Book)
1. Introduction to the Chapter
The chapter begins with the story of Yangdol and Dorjay, two children from Nubra in Ladakh. Living in a place with very clean skies, they observe thousands of stars every night. Their curiosity leads us to learn about stars, constellations, planets, the solar system, galaxies and the universe.
2. Stars and Constellations
What are Stars?
- Stars are large, hot balls of gases.
- They shine with their own light.
- Some stars are bright while others appear dim.
Patterns in the Sky
- Certain groups of stars form patterns that look like familiar shapes.
- These patterns are called constellations.
- Long ago, people used these patterns to find directions while travelling.
Constellations
- Earlier: only the patterns were called constellations.
- Today: the entire region of the sky is defined as a constellation.
- The International Astronomical Union (IAU) has listed 88 constellations.
Important Constellations
- Orion (The Hunter)
- Has three stars in the middle forming the “belt”.
- Contains the red giant star Betelgeuse.
- Canis Major
- Contains Sirius, the brightest star in the night sky.
- Taurus
- Contains Aldebaran (Rohini) and the Pleiades cluster (Krittika).
- Big Dipper & Little Dipper
- Big Dipper is part of Ursa Major (Sapta Rishi).
- Little Dipper is part of Ursa Minor.
- Pole Star (Polaris) is part of the Little Dipper and appears fixed in the sky.
Pole Star
- Appears stationary in the northern sky.
- Helps in identifying the North direction.
3. Night Sky Watching
Why can we see more stars in villages?
- Because of less light pollution.
- Smoke, dust, and bright artificial lights in cities hide stars.
Best Conditions to Watch the Sky
- Moonless night
- Open space without buildings or trees
- Clear sky without clouds
- After eyes adjust to darkness for 30 minutes
Tools to Identify Sky Objects
- Sky Map app
- Stellarium app
- Magnetic compass
- Printed sky charts
Visibility of Constellations
- Not every star or constellation is visible every night.
- Some stars (like Pole Star) cannot be seen from the Southern Hemisphere.
4. Solar System
Sun
- A star closest to the Earth.
- Extremely hot, glowing ball of gases.
- Main source of heat and light.
- About 100 times bigger than Earth in diameter.
- About 150 million km away (1 Astronomical Unit).
Why other stars are not visible in daytime?
- The Sun is too bright; it hides the light of other stars.
5. Planets
Definition
- Large, nearly spherical objects.
- Revolve around the Sun in fixed paths.
Eight Planets (in order of distance from Sun)
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
Inner (Rocky) Planets
- Mercury, Venus, Earth, Mars
- Smaller in size
- Have solid surfaces
Outer (Gas Giant) Planets
- Jupiter, Saturn, Uranus, Neptune
- Very large
- Mostly made of gases
- Have rings around them
Special Points
- Venus: brightest; called Morning/Evening Star (but not a star).
- Mars: Red Planet due to reddish soil.
- Earth: Blue Planet due to abundant water.
- Pluto: Now considered a dwarf planet (not a main planet).
How to identify planets in the sky?
- Planets do not twinkle, while stars do.
- Venus and Jupiter are easily seen with naked eyes.
6. Satellites
Natural Satellites
- Objects that revolve around planets.
- Earth has one Moon.
- Mars has two moons.
- Jupiter, Saturn, Uranus, Neptune have many moons.
The Moon
- Earth’s natural satellite.
- Takes 27 days to revolve around Earth.
- One-fourth the size of Earth.
- Has craters formed by asteroid impacts.
- No air, water or life.
India’s Moon Missions
- Chandrayaan-1 (2008)
- Chandrayaan-2 (2019)
- Chandrayaan-3 (2023): Successful soft landing near the south pole
- Chandrayaan-4: Planned sample return mission
7. Asteroids and Comets
Asteroids
- Rocky, irregular-shaped objects.
- Found mostly between Mars and Jupiter (Asteroid Belt).
Comets
- Icy, rocky objects with long glowing tails.
- Tail forms when they come close to the Sun.
- Famous comet: Halley’s Comet (seen every 76 years).
8. Beyond the Solar System
Milky Way Galaxy
- Our home galaxy.
- Appears as a faint glowing band across the sky.
- Contains billions of stars.
- The Solar System is part of the Milky Way.
Universe
- Contains countless galaxies.
- Scientists study galaxies to understand the Universe.
Life Beyond Earth
- Scientists search for life on exoplanets.
- No evidence found yet.
Summary of the Chapter
- Stars form patterns called constellations.
- Pole Star helps in finding direction.
- The Sun is a star and the main source of energy.
- A planet orbits the Sun; there are eight planets.
- The Earth takes one year to revolve around the Sun.
- Natural satellites move around planets; the Moon is Earth’s satellite.
- The Solar System includes the Sun, planets, moons, asteroids, and comets.
- Our Solar System lies within the Milky Way Galaxy.