3. An Introduction to
EarthEarth, the planet on which we
live was formed about 4.5
billion years ago. It is fifth
largest in the solar system and
first largest in the inner
planets of the solar system. It
has the 3rd position from the
sun and 6th position from
outer planets. It is known as
the unique planet because
it is the only planet in the
universe which is known to
have life. 3
4. Motions of the Earth
The Earth is having two types of motions:-
4
Motions
Rotation Revolution
5. Rotation
Earth has an imaginary line on which
it rotates, known as Axis. Earth’s
orbit is slanting which makes unequal
days and nights on earth. When the
earth rotates on its axis, it is called
Rotation. Rotation causes days and
nights on earth. Earth takes 24 hours
to complete one rotation. Earth takes
rotation from west to east. Earth has
the speed of 30 km of rotation on
equator while on poles it has 0 km.
Earth completes one rotation in 23
hours, 56 minutes and 4.1 seconds. 5
6. Revolution
Earth has an imaginary line on
which it goes around the sun,
known as Orbit. Earth’s orbit is
oval which brings the earth near
the sun and far from the sun. when
the earth goes around the sun, it is
called Revolution. Revolution
causes changes in the seasons on
the earth. Earth takes 365 days, 5
hours, 48 minutes and 56 seconds
(3651/4 days) to complete one
revolution. Revolution also runs
from west to east. 6
7. Layers of the Earth
Earth has three types of layers, they are:-
7
Layers
Crust
Mantle
Core
8. Crust
The crust ranges from 5–70 km
(3–44 miles) in depth and is the
outermost layer. The crust is of
two types:-
8
Crust
Continental
Oceanic
9. Core
Core is the innermost layer of the earth. The core is
of two types:-
9
Core
Inner
Outer
10. The Story of Earth
As you know, the earth was formed about 4.6 billion
years ago, it’s story starts. The Earth will live 4.5
million years more. If you want to watch the story of
the earth, here’s a hyperlink.
10
11. EARTH
• Every day is about 55 billionths of a
second longer than the day before it
12. Earth
• Approximately 70 percent of the
earth is covered by water. Only 1
percent of this water is drinkable.