The document discusses the structure of the universe including galaxies, the Milky Way galaxy, and our solar system. It describes how galaxies are vast collections of stars, dust, and gases that appear in clusters. It also provides details about the shape of the Milky Way galaxy and explains that we cannot see it from Earth as shown in images. Additionally, it summarizes the major components of our solar system, including the sun, inner and outer planets, dwarf planets, and small bodies like asteroids and comets that orbit the sun.

1. THE UNIVERSE

3. GALAXIES
•Galaxies are
a vast
collection of
stars, dust
and gases.
•They appear
in groups
called galaxy
clusters.
(Local Group
is our galaxy
cluster)
•Our galaxy is
the Milky
Way.

4. MILKY WAY

5.  What shape is the Milky Way?
Can we see the Milky Way from Earth as it is shown in the image?
Why or why not?

6. 1. WHAT IS THE UNIVERSE LIKE?
Geocentric theory
 2nd century B.C.
 Proposed by Ptolomy.
 The Earth was the
center of the
Universe.
 The Sun, Moon and
planets orbited the
Earth.

7. 1. WHAT IS THE UNIVERSE LIKE?
Heliocentric theory
 In 1542
 Proposed by Nicolaus
Copernicus
 The Sun was the
center of the
Universe

8. ¿ASTRONOMY OR ASTROLOGY?

11. WHEN DID THE UNIVERSE BEGIN?
BIG BANG
17.000 m.y. ago

12. IS THERE ANY EVIDENCE?

13. 2. HOW BIG IS THE UNIVERSE?

14. WHAT UNIT OF MEASUREMENT DO
ASTRONOMERS USE?
 Astronomical unit (AU) is the distance between
the Earth and the Sun= 150 million kilometres.
Express the distance of Mercury, Mars and Pluto
from the Sun in kilometres:
 Mercury: 0,4 AU =
 Mars: 1,5 AU=
 Pluto: 39,4 AU=
0,4 x 150.000.000 = 60.000.000 Km
1,5 x 150.000.000 = 225.000.000 Km
39,4 x 150.000.000 = 5.910.000.000 Km
 Light year. It is the distance light travels in a
year. Light travels 300,000 km per second.
This distance is equivalent to roughly
9,461,000,000,000

16. 4. WHAT MAKES UP THE SOLAR
SYSTEM…?

17. SUN
It’s a medium-sized
star.
The Sun consists mainly
of two gases: 75%
hydrogen (H) and 25%
helium (He).
Temperature of the
nucleus 15.000.000 ºC.
So hot inside that it
emits heat and light
through nuclear fusion.
It rotates on its axis in
an anticlockwise
direction (once every
25-30 days)
It was formed when clouds of gases pull together by gravitational forces.

18.  What is the name of the process that takes
place inside the Sun’s nucleus?
 What happens during this process?

20. PLANETS
Planets are
spherical bodies
which revolve
around the Sun.
They move in
elliptical orbits.
Mercury, Venus,
Earth and Mars
are made up
mainly of rock.
(Rocky planets)
Jupiter, Saturn,
Uranus and
Neptune are made
up mainly of
gases. (Gaseous
planets)
Rocky planets
or inner planets
have a crust and
a mantle made
of rock and a
metallic core.
Gaseous planets
or outer planets
are made up
mainly of gas.

21. Elliptical orbits

22. WHICH ARE THE INNER PLANETS?

23. Mercury
Mercury is the closest planet to the Sun
 It is the smallest planet in the Solar System
 It has no natural satellites.
 It has no atmosphere
 There are lots of craters on its surface
 Huge differences in night and day
temperatures (From -170ºC to 480ºC)

24. Venus
Venus is similar in size to Earth.
 It has an extremely dense atmosphere which
consists mainly of carbon dioxide (CO2). This
thick atmosphere makes it the hottest planet
of the planetary system, with surface
temperatures over 450°C.
Venus has no natural satellites.
One day in Venus lasts more than one Earth
year.

25. Earth
 Earth is the largest and densest of the inner
planets
 It’s the only planet known to have life.
 Its liquid hydrosphere is unique among the
inner planets. (Average surface temperature
= 15ºC)
 Earth's atmosphere has been altered by the
presence of life to contain 21% free
oxygen. (78% N2)
 It has one satellite, the Moon.

26. Mars
Mars is smaller than Earth and Venus.
 It has a thin atmosphere that contains 95%
carbon dioxide, so it’s not breathable.
 It’s surface resemble the Earth’s rocky
deserts.
Mars has two tiny natural satellites
(Deimos and Phobos).

27. WHICH ARE THE OUTER PLANETS?

28. Jupiter
 Jupiter is the largest planet of the Solar System.
 It is composed largely of hydrogen (90%) and
helium (10%).
 Jupiter has more than 60 known satellites.
 The four largest satellites are Ganymede, Callisto,
Io, and Europa.
 There are bands of different coloured clouds
around the planet, parallel to the equator.

29. Saturn
 Saturn, famous for its extensive ring
system made of ice, small rocks and dust
particles.
 Its composition is very similar to Jupiter’s.
(97% Hydrogen, 3% Helium)
 Saturn also has more than 60 known
satellites. The largest one is Titan.

30. Uranus
 Uranus is the lightest of the outer planets.
 It’s a frozen planet, with very low surface
temperatures.
One unique feature of Uranus is its axial tilt.
The planet rotates on its side with a tilt over
ninety degrees to the ecliptic.
 It also has a ring system
 Uranus has 27 known satellites.

31. Neptune
 Neptune is slightly smaller than Uranus.
 It has 13 known satellites. The largest one
is Triton.

33. Elliptical orbits

34. DWARF PLANETS
They are
spherical
bodies that
orbit the Sun.
They are
smaller than
planets.
They have not
cleared the
area in which
they orbit.
In the
Asteroid belt
Further than Pluto

35. DWARF PLANETS Asteroid belt

36. SMALL SOLAR SYSTEM BODIES
These are
other celestial
bodies that
orbit the Sun.
They include
asteroids,
comets and
satellites.

37. Asteroids
 Between the orbits of Mars and Jupiter is located
the Main Asteroid Belt. Asteroids are rocky
bodies that range in size from hundreds of
kilometres across to microscopic.

38. Comets
 Comets are composed largely of volatile ices,
dust and fragments of rock. When a comet
enters the inner Solar System, its proximity to the
Sun causes its icy surface to sublimate and
ionise, creating a coma, which is a long tail of
gas and dust often visible to the naked eye.
 Short-period comets, such as Halley's Comet,
are believed to originate in the Kuiper belt (30-
1.000 A.U. from the Sun), while long-period
comets, such as Hale-Bopp, are believed to
originate in the Oort cloud (60.000 A.U. from the
Sun)

39. Satellites or moons
They orbit
some planets.
The Earth’s
natural
satellite is the
Moon.

40. Trans neptunian regions:
Kuipert belt (30-1000 AU) and Oort cloud (60.000 AU)

41. PLAY THESE GAMES
http://www.educaplay.com/es/recursoseducativos/102
3849/solar_system.htm
http://www.educaplay.com/es/recursoseducativos/102
3852/classify_planets.htm
http://www.educaplay.com/es/recursoseducativos/102
3853/which_planet_.htm

42. HOW DO THE PLANETS MOVE?
 http://esminfo.prenhall.com/science/geoanimations/
animations/01_EarthSun_E2.html