UNIT 9: THE SOLAR SYSTEM

UNIT 9: THE SOLAR SYSTEM

Index:

1.1.- The Solar System

1.2.-The Sun

1.3.- Planets and Satellites

1.4.- Other celestial bodies in the Solar System

1.1.- THE SOLAR SYSTEM

- The Solar System is made up of the Sun and all the stars that orbit around it.

- The Earth is also part of the Solar System.

1.2.- THE SUN

- The Sun is the closest star to the Earth.

- It is a huge mass of gasses made up of mainly hydrogen that is shaped like a sphere.

- Because its surface is very hot, it gives us energy in form

  of light and heat.

-       When the Sun is in the sky, it is day. When we cannot see the Sun, it is night.

1.3. PLANETS AND SATELLITES

- The planets of the Solar System do not have their own light.

- They spin around their own axes and orbit around the Sun.

- Almost all the planets have satellites. Satellites are celestial bodies without their

  own light that orbit around a planet.

The eight planets of the Solar System are classified into two groups:

Inner planets:	Outer planets:
-       They are the closest to the Sun.	-       They are the farthest from the Sun.
-       They are smaller than the outer planets.	-       They are much larger than the inner planets.
-       They have a solid rock surface.	-       They are made up of gasses like hydrogen and helium.
-       Their density is high.	-       Their density is low.
Inner planets are: Mercury, Venus, Earth and Mars.	Outer planets are:  Jupiter, Saturn, Uranus and Neptune. They are surrounded by many satellites.

1.4.- OTHER CELESTIAL BODIES IN THE SOLAR SYSTEM

Our solar system is also made up of asteroids, meteorites, comets and dwarf planets (planetas enanos).

·                     Asteroids:

-       They are fragments of rock or metal that move around the Sun.

-        They are smaller than planets.

-        Most of them are placed between Mars and Jupiter what is called asteroid belt.

·                     Meteorites:

-       They are craters formed on the surface when asteroids hit (impactan sobre) a planet or a satellite.

-       Small meteorites that disintegrate in our atmosphere are called shooting stars.

·                     Comets: 

-       They are made of rock and ice.

-       They come from two areas: The Oort Cloud (la Nube de Oort) and The Kuiper Belt (el Cinturón de Kuiper).

-       Solar energy evaporates the ice which forms the tail. This glowy path (estela luminosa) can have millions of kilometers.

·                     Dwarf planets: 

-       They are smaller than planets.

-       They orbit the Sun further away than Neptune.

-       Pluto is the most well known.

ACTIVITIES – SOLAR SYSTEM

·         1. Match the two columns.

·                                                               They are made up of gases.
Inner Planets                                   They are far from the Sun.
                                                      They are small (the Earth is one of them).
Outer Planets                                   They are very large.
                                                      They are close to the Sun.

·          

·         2. Write the names of the planets.

a) Inner planets: _______________________________________________________________
b) Outer planets: _______________________________________________________________