The document discusses the Earth and its movement. It begins by explaining how the universe formed over 13.7 billion years and includes celestial bodies, galaxies, and planetary systems with a star and objects orbiting it. The Earth formed 4.6 billion years ago and is the only planet that supports life. It can support life because it has a moderate temperature, an atmosphere with oxygen, water, and its shape is spherical. The Earth rotates on its axis, causing day and night, and it orbits the sun over 365 days, causing seasons. Its rotation and orbit are responsible for its climate zones and the length of days and nights changing over the year.

1. 1º B
Unit 1: The Earth, the living planet

2. The universe, the solar system and the Earth
The universe has begun 13.700 milion of years
ago.
includes:
●celestial bodies (stars, planets, satellites...)
●intergalactic matter (dust and gas)
●intergalactic space

3. The celestial bodies form Galaxies
Each galaxy
contains milions
of milions of stars
and many
planetary
systems

4. The planetary systems
consists of
●A star
●the celestial bodies that go
around it (planets, satellites,
asteroids and comets).

5. The Earth, the living planet
- was formed 4.600 milions of
years ago, like the Sun and all
the solar system.
- is the only planet with life

6. Why the Earth is the only planet with life?
1. Temperature is moderate.
2. The atmosphere contains essential
gases for human life, as oxygen. Besides,
the atmosphere protects us from unhealthy
solar radiations and it helps us keeping its
temperature.
3. The Earth has plenty of liquid water.
This water is a large part of the Earth's
surface, forming oceans and seas, for this
reason, we see the Earth from space blue.

7. Shape and dimensions of the Earth
-The Earth' shape is almost spherical which is
why it is represented by a globe.
-The Earth has 510 milions of km2, a thousand
times Spain' surface.
-The Earth is a small celestial body in the whole
universe.

8. The Earth in motion
The universe and its asteroids are constantly moving.
The Earth is constantly moving
Rotation
Orbiting

9. Rotation
Rotation is the turning of the Earth
around its imaginary axis; at either
end of the axis are the poles. A
full rotation takes 24 hours (a day)
The main consequences of the Earth’s movement are
the change from day to night and vice versa.

10. Whats happen if the Earth doesn’t rotate?
I f t h e E a r t h d o e s n o t r o t a t e , h a l f o f t h e p l a n e t w o u l d a l w a y s
b e l i g h t a n d t h e t e m p e r a t u r e w o u l d b e e x t r e m e l y h o t w h i l e
t h e o t h e r h a l f w o u l d b e i n d a r k n e s s a n d w o u l d b e e x t r e m l y
c o l d .

11. Orbiting
The orbit is the movement of the Earth around the Sun.
It takes 365 days, 6hours and 9 minutes.

12. Consequences of the Earths' orbit
● The season of the year: Due to orbiting and the inclination of the Earth's
axis, each of the two hemispheres has a different exposure (exposición) to
the Sun's rays.
- In summer the rays fall directly on one hemisphere, while the other
receives them with a strong inclination, making winter.
- In spring and autumn the rays fall on both hemispheres with the
same inclination. When it is spring in one hemisphere it is autumn in the
other.
● Different duration of night and days.
●The different climate zones: depending on the latitude, the Sun's rays
fall with a different inclination. We can distinguish:
- One warm zone
-Two temperate zones.
Cold zone
- Two cold zones.
Warm zone
Temperate zone
Cold zone