CHAPTER 13
The Earth And Beyond
Submitted by:
Sarita Karki
VIII ‘C'
"Earth and Beyond" is a fascinating
topic that explores the universe
beyond our planet.
Now lets
start
■ Gravity: Gravity is the force that keeps us and everything
on Earth grounded. It also keeps the Moon in orbit around
our planet.
■ Planets: Planets are large objects that orbit the Sun. Earth
is just one of them, and there are eight others in our solar
system.
■ Stars: Stars are big, hot balls of gas that produce light and
heat. The Sun is our closest star, and it provides us with
light and warmth.
■ Moon Phases: The Moon changes shape in the sky
throughout the month, showing different phases like
crescents, half-moons, and full moons.
■ Space Missions: Scientists and astronauts travel to space
on missions to learn more about the planets, stars, and
galaxies. They use special spacecraft to explore.
■ Telescopes: Telescopes are like super binoculars that
help us see distant objects in space, like other planets
and faraway galaxies.
■ Space Travel: Humans have been to the Moon, and there
are plans to go to Mars in the future. Space travel is a
fascinating adventure.
■ Aliens and Life: Scientists are curious about whether life
exists on other planets. They search for clues that might
show us if there are aliens out there.
■ Our Galaxy: Our galaxy, the Milky Way, is like a giant city
of stars. It's just one of many galaxies in the universe.
■ Space Technology: Technology from space exploration
has given us things like GPS, weather forecasts, and
communication with satellites.
Luminous and Non Luminous
Objects
■Luminous object
■ Luminous object s are objects that has light of their
own.
■ For Example:
■ Sun: it has its own light and it Is a big ball of hot gases
which produces heat
■ Stars: it has its own light and it twinkles at the night
sky.
■Non- Luminous Objects
■ Non-luminous objects are objects that do not emit their
own light but can be seen because they reflect light
■ For Example:
■ Table: A table does not produce its own light. It is visible
because it reflects light from a light
■ Chair:chair is a non-luminous object. It appears visible
when light from a source
■ Book: Books are non-luminous objects as well.
Topic: Visibility of Heavenly Objects
■ Heavenly objects include stars, planets, moons, comets, and galaxies. They
are visible in the night sky due to the reflection of sunlight or their intrinsic
light.
■ Starry Sky: Stars are visible at night when the sky is dark. Light pollution
from cities can make it harder to see them. The patterns of stars are known
as constellations.
■ Planets: Some planets in our solar system are visible to the naked eye. They
don't twinkle like stars and move across the sky. Notable ones are Venus (the
evening or morning star), Mars, Jupiter, and Saturn.
■ Moon: The Moon is one of the brightest objects in the night sky. It goes
through phases, from a thin crescent to a full moon, and back again.
■ Meteor Showers: Occasionally, you can see meteor showers when the Earth
passes through a comet's debris field. Meteors (shooting stars) streak across
the sky.
■ Eclipses: Solar and lunar eclipses occur when the Earth, Moon, and
Sun align. Solar eclipses happen during the day, while lunar eclipses
occur at night.
■ Telescopes and Binoculars: Using these optical instruments can
enhance the visibility of heavenly objects. Telescopes can reveal
details of planets and galaxies.
■ Dark Skies: To see more celestial objects, it's best to observe from
locations with minimal light pollution, like rural areas or designated
dark sky sites
■ Time and Seasons: The visibility of heavenly objects changes with
time and seasons. Different constellations and planets become visible
at different times of the year.
■ Stargazing Tips: Patience, clear skies, and a basic understanding of
the night sky are important for successful stargazing.
Picture of heavenly objects
Topic :The Plantery Motion
■ Planetary motion refers to the movement of planets in our solar
system. It can be understood through the following key points:
■ Orbit: Planets orbit, or revolve around, the Sun. Each planet follows
an elliptical path, which is an elongated circle.
■ Rotation: Planets also rotate on their axes. This rotation causes day
and night on the planets. The time a planet takes to complete one full
rotation is its "day."
■ Revolution: The time a planet takes to complete one orbit around the
Sun is its "year." Different planets have different lengths of years. For
example, Earth takes approximately 365 days to complete one orbit.
■ Kepler's Laws: Johannes Kepler formulated three laws of planetary
motion.
Understanding planetry Motion
ACTIVITY TIME
■ Number the members in each group from 1 to 6
■ Will give 5 minutes to discuss..
■ Then will call the group number and member number
Question 1
■ What causes the changing of seasons on Earth?
Describe the tilt of the Earth's axis and its impact
on seasons."
Answer
■ The changing of seasons on Earth is caused by
the tilt of the Earth's axis. As the Earth orbits the
Sun, different parts of the Earth receive varying
amounts of sunlight due to this tilt. When one
hemisphere is tilted toward the Sun, it
experiences summer, while the other hemisphere
tilted away from the Sun experiences winter.
Question 2
■ How do we see different constellations in the
night sky throughout the year? Explain the
concept of apparent motion of stars."
Answer
■ We see different constellations in the night sky
throughout the year because of the Earth's orbit
around the Sun. The concept of apparent motion
of stars is due to this orbital motion. Stars appear
to move in the night sky, and this movement is a
result of the Earth's changing position as it orbits
the Sun.
Question 3
■ What is the name of the nearest star to Earth?
Answer
■ The nearest star to Earth is the Sun.
Question 4
■ Which planet in our solar system is known as the
"Red Planet"?
Answer
■ Mars is often referred to as the "Red Planet" due
to its reddish appearance.
Question 5
■ Who is known as the "father of modern
astronomy" and developed the laws of planetary
motion?
Answer
■ Johannes Kepler is known as the "father of modern
astronomy" and formulated Kepler's Laws of
Planetary Motion.
■THANK
YOU
