The document provides information about the universe, what composes the universe, constellations, units of measurement used by astronomers, and details about the solar system. It explains that the universe is made up of galaxies, nebulas, stars, planets, and other celestial bodies. It describes the geocentric and heliocentric models of the solar system and notes that Galileo proved the heliocentric model. It provides details about the sun, planets, dwarf planets, comets, asteroids, and satellites that make up the solar system. Finally, it discusses the difference between natural and artificial satellites and defines key terms.

1. UNIDAD: 1.- El universo
¿CÓMO ES EL UNIVERSO?
Los científicos desarrollaron dos teorías diferentes para explicar como era el Universo.
• Teoría geocéntrica: En el siglo Segundo AC, Ptolomeo propuso que la Tierra era el centro
del universo. El Sol, la Luna y los planetas giran alrededor de la Tierra.
• Teoría heliocéntrica: En 1.542, Nicolás Copérnico propuso que el Sol era el centro del
universo. La Tierra, la Luna y el resto de los planetas orbitaban el Sol.
En 1.610, Galileo Galilei inventó el telescopio y comprobó el modelo heliocéntrico.
¿QUÉ COMPONE EL UNIVERSO?
El universo es toda la materia, energía y espacio que existe. El universo está compuesto por:
• Galaxias: Son grandes cantidades de estrellas, polvo y gases, que permanecen juntas por la
atracción gravitacional. Aparecen en grupos llamados grupo de galaxias. Los científicos
creen que el vasto espacio entre galaxias está vacío. Nuestra galaxia se llama Vía Láctea.
• Nebulosas: Son enormes nubes de gases y polvo en el espacio.
• Estrellas: Son inmensas bolas de gases calientes. Hay tanto calor en su interior que emiten
calor y luz. Su energía viene de reacciones en el interior. Una galaxia puede tener quinientos
mil millones de estrellas.
• Planetas: Son cuerpos celestes que orbitan una estrella. No emiten luz, ellos reciben luz de
una estrella. Los planetas forman sistemas planetarios. Nuestro sistema planetario es el
Sistema Solar. Está formado por ocho planetas, y una estrella, el Sol, así como satélites,
cometas, y asteroides.
¿QUÉ SON LAS CONSTELACIONES?
Si miras al cielo de noche, puedes ver muchas estrellas. Si tu imaginación une las estrellas
con líneas, puedes imaginar figuras en el cielo. Las Constelaciones son imaginarios dibujos de
brillantes estrellas.
Los antiguos griegos inventaron las constelaciones que nosotros llamamos ‘los doce signos
del zodíaco’.
El cielo de noche es diferente en los hemisferios norte y sur, por lo tanto las constelaciones
son diferentes también.
Hay 88 constelaciones oficiales. Sin embargo, la mayoría de ellas no parecen realmente las
míticas figuras que representan.
¿QUÉ UNIDADES DE MEDIDA USAN LOS ASTRÓNOMOS?
• Unidades Astronómicas (UA): Es la distancia desde la Tierra al Sol. Aproximadamente 150
millones de kilómetros.
• Año-luz: Es la distancia que recorre la luz en un año. La luz viaja a 300.000 km en un
segundo, por esto un año-luz es aproximadamente 9,500,000,000,000 km.

2. EL SISTEMA SOLAR (I)
El Sistema Solar se formó hace aproximadamente cinco mil millones de años del gas y del
polvo de una nebulosa.
Nuestro Sistema Solar está formado por:
• El Sol: Compuesto principalmente de dos gases: hidrógeno y helio. La enorme presión y
temperatura en su interior, transforma el hidrógeno en helio, en este cambio se genera una
enorme cantidad de energía.
• Planetas: Son cuerpos esféricos que giran alrededor del Sol. Hay ocho planetas: Mercurio,
Venus, Tierra, Marte, Júpiter, Saturno, Urano y Neptuno.
• Planetas enanos: Son cuerpos esféricos que orbitan al Sol. Son más pequeños que los
planetas. Plutón, Ceres y Eris son planetas enanos.
• Pequeños cuerpos del Sistema Solar: Son otros cuerpos celestes pequeños que orbitan al
Sol.
EL SISTEMA SOLAR (II)
Además del Sol, los planetas, los planetas enanos, nuestro Sistema Solar está formado por los
Pequeños Cuerpos del Sistema Solar. Estos son otros cuerpos celestes pequeños que orbitan al
Sol. Incluyen:
• Satélites: Son cuerpos celestes que orbitan algunos planetas. El satélite natural de la Tierra
es la Luna. Si el satélite lo coloca el hombre, es un satélite artificial, se usa para recibir y
transmitir señales.
• Cometas: Son pequeños cuerpos que viajan alrededor del Sol en grandes orbitas elípticas.
Tienen forma irregular. El núcleo está constituido por una masa de hielo, polvo, y gas.
Cuando los cometas viajan cerca del Sol, parte del hielo se evapora, creando las largas y
brillantes colas de los cometas.
• Asteroides: Son objetos rocosos que tienen forma irregular. Pueden tener varios kilómetros
de diámetro, pero la mayoría tienen solo unos pocos de metros de ancho. Los asteroides
orbitan alrededor del Sol. La mayoría de ellos están entre las órbitas de Marte y Júpiter. Esta
zona se llama cinturón de asteroides.
¿CUÁLES SON LOS PLANETAS INTERIORES?
Los planetas interiores son los cuatro planetas más cercanos al Sol: Mercurio, Venus,
Tierra y Marte. En estos planetas la corteza y el manto están constituidos por rocas y el centro es
metálico.
CARACTERISTICAS
Mercurio Venus Tierra Marte
Diámetro (km) 4.000 12.000 12.740 6.794
Temperatura (ºC) - 180 a 430 ºC 465 ºC - 89 a 58 º C - 82 a 0 ºC
Atmósfera Ninguna CO2 N2 y O2 CO2
Satélites 0 0 1 2
¿CUÁLES SON LOS PLANETAS EXTERIORES?
Los planetas exteriores son: Júpiter, Saturno, Urano y Neptuno. Se llaman gigantes
gaseosos porque están compuestos principalmente de gases.
CARACTERÍSTICAS
Júpiter Saturno Urano Neptuno
Diámetro (km) 142.984 120.536 51.118 49.492
Temperatura (ºC) - 150 ºC - 170 ºC - 200 º C - 210 ºC
Atmósfera H2 y He H2 y He H2 y He H2 y He
Satélites 63 59 27 13

4. NAME: ___________________________________________ DATE: ________ 1º ___ (Bilingual)
UNIT: 1. – THE UNIVERSE
HOW IS THE UNIVERSE?
Scientists developed two different theories to
explain what the Universe was like.
• Geocentric theory: In the second century
BC, Ptolemy proposed that the Earth was the
centre of the universe. The Sun, Moon and
planets revolve around the Earth.
• Heliocentric theory: In 1,542, Nicolas
Copernicus proposed that the Sun was the
centre of the universe. The Earth, the Moon
and the rest of the planets orbited the Sun.
In 1,610, Galileo Galilei invented the telescope, and proved the
Heliocentric model.
1.- Copy this text in the box:
2.- Translate these words:
Universe: Geocentric theory:
The Earth: Heliocentric theory:
The Moon: The Sun: Planet:
3.- Write the symbol of each celestial body:
Sun Venus
Earth Mars
Moon Jupiter
Mercury Saturn
4.- a) Who was Ptolemy?:
b) Who was Galileo Galilei?:

5. 5.- Who was Nicolas Copernicus?
6.- Write the symbol of each celestial body:
Sun Venus
Earth Mars
Moon Jupiter
Mercury Saturn
7.- a) Label this picture:
b) Which model does this picture represent?
8.- Which theory does this picture represent?:__________________________
Why?: Because ________________________________________
______________________________________________________
______________________________________________________
9.- Look at both pictures carefully. What are the differences
between both theories?
10.- Look at both pictures carefully. What things are
common between both theories?

6. NAME: ___________________________________________ DATE: ________ 1º ___ (Bilingual)
WHAT MAKE UP THE UNIVERSE?
The universe is all the matter, energy and space that exist. The universe is made up of:
• Galaxies: They are large quantities of stars, dust and gases, held together by the gravitational
attraction. They appear in groups called galaxy cluster. Scientists think the vast spaces
between the galaxies are empty. Our galaxy is called Milky Way.
• Nebulas: They are enormous clouds of gases and dust in the space.
• Stars: They are immense balls of hot gasses. There are so hot inside that they emit heat and
light. Its energy comes from reactions in the interior. A galaxy can have up to five hundred
thousand millions stars.
• Planets: They are celestial bodies that orbit a star. They do not emit light; they receive light
from the star. The planets form planetary systems. Our planetary system is the Solar
System. It is made up of eight planet, and star, the Sun, as well as satellites, comets, and
asteroids.
1.- Copy this information:
2.- Translate these words:
Galaxies: Galaxy cluster: Nebula:
Star: Milky Way: Planet:
Sun: Planetary System: Satellite:
Comet: Energy and space: Asteroid:
3.- What are there between a galaxy and other galaxy?.
4.- What is a nebula?
5.- How many stars can a galaxy have?

7. 6.- Match with arrows:
Spiral galaxy
Elliptical galaxy
Irregular galaxy
7.- a) What is a galaxy?:
b) What is the name of our galaxy?
8.- What is a star?
9.- a) What is a planet?
b) Which celestial bodies form the universe?:
10.- Match with arrows:
Galaxy
Star
Nebula
Planet
Comet
Asteroid
Satellite

8. NAME: ___________________________________________ DATE: ________ 1º ___ (Bilingual)
WHAT ARE CONSTELLATIONS?
If you look at the sky at night, you can see lots of stars. If your imagination joins stars with
lines, you can imagine figures in the sky. Constellations are imaginary patterns of bright stars.
The Ancient Greeks invented the constellations we call ‘the twelve signs of zodiac’.
The night sky looks different in the Northern and Southern hemispheres, therefore the
constellations are different too.
There are 88 official constellations. However, most of them do not really look like the
mythical figures they represent.
1.- Copy this information:
2.- Translate these words:
Constellation: Signs of zodiac:
Northern hemisphere: Southern hemisphere:
3.- What are constellations?:
4.- a) How many signs does ‘the zodiac
have?
b) Who invented ‘the zodiac’?
5.- a) Write the names of the zodiac
constellations:
6.- a) How many official constellations are
there?

9. b) Do the constellations look like the figures they represent?
WHAT UNITS OF MEASUREMENT DO ASTRONOMERS USE?
• Astronomical unit (AU): This is the distance from the Earth to the Sun. Approximately 150
million kilometres.
• Light-year: This is the distance light travels in one year. Light travels 300,000 km in one
second, for therefore one light-year is approximately 9,500,000,000,000 km.
7.- a) What is one Light-year?
b) What is one Astronomical unit?
8.- Complete:
a) 1 AU = ______________________________ km
b) 1 Light-year = ________________________ km
c) 5 AU = ______________________________ km
d) 10 Light-year = ________________________ km
9.- Complete:
a) Two stars are separated by 38,000,000,000,000 km. How many Light-years separate these
stars?
38,000,000,000,000 km = _____________________ Light-years
b) Two stars are separated by 38,000,000,000,000 km. How many AU separate these stars?
38,000,000,000,000 km = _____________________ UA
9.- Order from lower distance to higher distance:
a) From A to B there is 5,000,000,000 km
b) From C to D there is 0,5 AU
c) From E to F there is 0,5 Light-year
d) From G to H there is 500,000,000,000 m

10. NAME: ___________________________________________ DATE: ________ 1º ___ (Bilingual)
THE SOLAR SYSTEM (I)
The Solar System was formed approximately five thousand million years ago from the gas
and dust of a nebula.
Our Solar System is made up of:
• The Sun: It consists mainly of two gases: hydrogen and helium. The enormous pressure
and temperature inside transform the hydrogen into helium, in this change it generate a
enormous amount of energy.
• Planets: They are spherical bodies which revolve around the Sun. There are eight planets:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
• Dwarf planets: They are spherical bodies which orbit the Sun. They are smaller than
planets. Pluto, Ceres and Eris are dwarf planets.
• Small Solar System bodies: They are other little celestial bodies which orbit the
Sun.
1.- Copy this information:
2.- Translate these words:
Solar System: Hydrogen: Helium:
Dwarf planet: Planet: Sun:
Small Solar System body: Nebula:
3.- Write the planets’ names:
4.- Label this picture:

11. 5.- How does the Sun generate its energy?
6.- What is the difference between planet and dwarf planet?
7.-Match with arrows:
Mercury
Neptune
Venus
Jupiter
8.-Match with arrows:
Earth
Mars
Saturn
Uranus
9.- Order the planets from larger to smaller:
10.- Label each picture:

12. NAME: ___________________________________________ DATE: ________ 1º ___ (Bilingual)
THE SOLAR SYSTEM (II)
Beside of the Sun, planets, and dwarf planets, our Solar System is made up of Small Solar
System bodies. These are other little celestial bodies which orbit the Sun. They include:
• Satellites: They are celestial bodies that orbit some planets. The Earth’s natural
satellite is the Moon. If the satellite is placed by man, it is an artificial satellite, it is used
for receiving and transmitting signals.
• Comets: They are small bodies that travel around the Sun in highly elliptical orbits.
They are irregular in shape. The nucleus is made up of a mass of ice, dust and gas. When the
comets travel close to the Sun, some of the ice evaporates, creating the long, bright tail of
the comets.
• Asteroids: They are rocky objects which are irregular in shape. They can be several
hundred kilometres in diameter, but most are only a few metres wide. Asteroids orbit around
the Sun. Most of them are between the orbits of Mars and Jupiter. This area is called the
asteroid belt.
1.- Copy this information_
2.- Translate these words:
Asteroid belt: Comet:
Natural satellite: Artificial satellite:
Dwarf planet: nucleus:
3.- What is the difference between ‘natural satellite’ and ‘artificial satellite’?
4.- What is the ‘asteroid belt’
5.- Fill-in the blanks:
This celestial body is a: ____________. Its parts are:
The ____________ that is made up of:
_________________________________

13. and the ___________ that is made up of: ______________________________
6.- What is the Moon?
7.- What is an asteroid?
8.- Match with arrows:
Natural satellite of the Earth
Artificial satellite of the Earth
Satellites of Mars
Satellites of Jupiter
Satellites of Saturn
Satellites of Uranus
Satellites of Neptune
9.- Match with arrows:
Asteroid
Comet
Asteroid belt
10.- Label this picture

14. NAME: ___________________________________________ DATE: ________ 1º ___ (Bilingual)
WHICH ARE THE INNER PLANETS
The inner planets are the four planets closest to the Sun: Mercury, Venus, Earth and Mars.
In these planets the crust and mantle are made of rock and the core is metallic.
CHARACTERISTICS
Mercury Venus Earth Mars
Diameter (km) 4,000 12,000 12,740 6,794
Temperature (ºC) - 180 to 430 ºC 465 ºC - 89 to 58 º C - 82 to 0 ºC
Atmosphere None CO2 N2 and O2 CO2
Satellites 0 0 1 2
1.- Complete the chart:
CHARACTERISTICS
Satellites Atmosphere Temperature (ºC) Diameter (km)
Mercury
Venus
Earth
Mars
2.- Translate:
Mercury: Venus: Mars:
Core metallic: Diameter: Temperature:
Atmosphere: Satellite: Crust of rock:
3.- Order these planets from larger to smaller:
4.- a) Order the planets from higher temperature to lower temperature:
b) Order the planets from more number of satellites to less number of satellites:
5.- a) What planets have C02 in its atmosphere?
b) What planets have 02 in its atmosphere?
c) What planets have N2 in its atmosphere?
d) What planets do not have any atmosphere?

15. WHICH ARE THE OUTER PLANETS
The outer planets are: Jupiter, Saturn, Uranus and Neptune. They are called gas giants
because they consist mainly of gases.
CHARACTERISTICS
Jupiter Saturn Uranus Neptune
Diameter (km) 142,984 120,536 51,118 49,492
Temperature (ºC) - 150 ºC - 170 ºC - 200 º C - 210 ºC
Atmosphere H2 and He H2 and He H2 and He H2 and He
Satellites 63 59 27 13
6.- Complete this chart:
CHARACTERISTICS
Satellites Atmosphere Temperature (ºC) Diameter (km)
Jupiter
Saturn
Uranus
Neptune
7.- Translate:
Jupiter: Saturn: Uranus: Neptune:
8.- Order these planets from larger to smaller:
9.- a) Order the planets from higher temperature to lower temperature:
b) Order the planets from more number of satellites to less number of satellites:
10.- Match with arrows
The centre of the Solar System •
It rotates around the Sun • • Sun
It rotates around the Earth • • Moon
A star • • planet
Mercury, Venus… •
There are a lot of these objects between Mars and Jupiter • • Comet
An artificial object in space • • Satellite
It has a core and a tail • • Asteroid