UNIT 5: THE UNIVERSE AND THE EARTH

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UNIT 5: THE UNIVERSE AND THE EARTH 1. THE EARTH, A PLANET IN THE SOLAR SYSTEM The Universe is enormous and contains billions of galaxies, stars, planets, satellites, asteroids and comets.

1 UNIT 5: THE UNIVERSE AND THE EARTH 1. THE EARTH, A PLANET IN THE SOLAR SYSTEM The Universe is enormous and contains billions of galaxies, stars, planets, satellites, asteroids and comets. It is thought that the Universe was created after the Big Bang, circa 14 billions years ago. The Earth is the only known inhabited planet. It is located in the Solar System, which belongs to the Milky Way galaxy. Our closest galaxy is called Andromeda, which is around 2.2 million light-years. A light -year is the distance covered by light in a year at the speed of km per second. Within the Milky Way there are more than 250 Solar Systems. A star is a huge ball of gas that gives out light and heat Stars can be different sizes, colours and temperatures.

2 Our Solar System was created when the big cloud of gas and dust reached 11,000,000ºC, which permitted the formation of a star, the Sun. In our Solar System there are eight planets and five dwarf planets. They have different sizes and satellites revolving around. Planets and satellites are celestial bodies that do not produce their own lights. Satellites revolve around planets. Planet Inner planets Asteroids belt Outer planets Distance Diameter Satellites Orbit s Rotation s to the (thousand period period sun km) (years) (days) (million km) Mercury Venus Earth Mars Jupiter Saturn 1, Uranus 2, Neptune 4, All the planets of the Solar System revolve around an only star. The orbits on which they revolve are elliptical. The inner planets are mostly rocky and small, whereas the outer planets are gaseous, big and they have many satellites revolving around them. The Earth s only satellite is called the Moon. 2. PLANET EARTH The Earth is not a perfect sphere, because it is slightly flattened at the poles. Some scientists say its shape is similar to an irregular geometric shape called a geoid. If you cut our planet in half, it would be divided into two hemispheres of equal size, the Northern Hemisphere and the Southern Hemisphere.

The 70% consists of water (oceans, seas, rivers, and lakes). The Southern Hemisphere is known as the maritime hemisphere because it is mostly made up of huge oceans.

There is liquid water on the surface. Our atmosphere contains the vital gases we need (21% oxygen, 78% nitrogen and 1% of other gases).

3 The 70% consists of water (oceans, seas, rivers, and lakes). The Southern Hemisphere is known as the maritime hemisphere because it is mostly made up of huge oceans. The 30% consists of land (continents and islands). The most of them are in the Northern Hemisphere. Life can exist on the Earth thanks to several factors: Mild temperature (around 15ºC average). There is liquid water on the surface. Our atmosphere contains the vital gases we need (21% oxygen, 78% nitrogen and 1% of other gases). It avoids excessive cooling and heating of the Earth and it filters the harmful solar radiations (UVA Rays and X Rays). Without the atmosphere it would be impossible the life on the Earth. 3. THE MOVEMENTS OF THE EARTH The Earth has two kinds of movements: Earth s orbit around the sun (revolution movement). Our planet moves at 30 km/sec following its elliptical orbit around the sun, which takes 365 days and 6 hours (that explains the leap years every four years, which have 366 days). It provokes the seasonal change due to the axial tilt. Rotation. The Earth spins on its own axis, which takes 24 hours: It moves from west to east. Therefore day and night are caused by the rotation since the sun just lights half of the Earth.

4. PARTS OF THE EARTH It is said that the Earth is composed by three different layers: the Atmosphere, the Hydrosphere and

It contains the ozone layer (25-40 km), which protects us from any radiations. - Mesosphere (50-85 km).

It is composed of seas, rivers, lakes, ice, and subterranean waters. It is more than 70% of the world.

4 4. PARTS OF THE EARTH It is said that the Earth is composed by three different layers: the Atmosphere, the Hydrosphere and the Lithosphere. Atmosphere. It has several layers: - Troposphere (<15 km). - Stratosphere (15-50 km). It contains the ozone layer (25-40 km), which protects us from any radiations. - Mesosphere (50-85 km). - Thermosphere ( km). - Exosphere (600-10,000 km). Hydrosphere. It is composed of seas, rivers, lakes, ice, and subterranean waters. It is more than 70% of the world. There are five oceans in the world: Atlantic, Pacific, Indian, Arctic and Antarctic Oceans. Lithosphere. It is composed of continents and the seabed. There are six continents in the world: Asia, America, Africa, Europe, Oceania and Antarctica.

5. REPRESENTATION OF THE EARTH: MAPS The way to represent the Earth has changed in the history. Until the 15th century it was thought that it was flat.

That was the origin of the cartography, the science in charge of representing the Earth. There are several ways to represent the Earth: It can be done through a terrestrial globe.

The most common way to represent the Earth is through maps. They are two-dimensional scale models of the Earth.

5 5. REPRESENTATION OF THE EARTH: MAPS The way to represent the Earth has changed in the history. Until the 15th century it was thought that it was flat. Christopher Columbus and other explorers proved that it was not such. Scientists helped measure the Earth and represent it. That was the origin of the cartography, the science in charge of representing the Earth. There are several ways to represent the Earth: It can be done through a terrestrial globe. It is the best way to represent the Earth because it is a three-dimensional scale model of the Earth. The main problem is that it cannot have many details. The most common way to represent the Earth is through maps. They are two-dimensional scale models of the Earth. They are done basing on mathematical formulas called projections, which adapt the geoidal shape of the Earth into a plan. There are several kinds of projections that depend on what we want to represent better, the most common ones are: Cylindrical projection. It represents the whole planet, taking the equator as its centre, so the farther the regions are from the equator the more distorted they are. The most known cylindrical projection is called Mercator, after its cartographer.

Conic projection. It represents high latitudes and the poles. The result is a map with semi-circular parallels and radial meridians.

The pole is the centre of the projection. That fact explains that the farther the region is from the pole the more distorted it is. Maps are an essential tool for studying the surface of our planet.

There are several kinds of maps: Topographic maps are general maps that show physical features (natural: relief, rivers ) and man-made features (artificial: cities, roads, crops ).

6 Conic projection. It represents high latitudes and the poles. The result is a map with semi-circular parallels and radial meridians. Distortion is minimal at the point where the cone intersects the globe but increases as we move away from that point. Azimuthal or planar projection. It just represents one hemisphere. The pole is the centre of the projection. That fact explains that the farther the region is from the pole the more distorted it is. Maps are an essential tool for studying the surface of our planet. A map is a two-dimensional representation of the Earth s surface. It has been reduced in size and shows information in a simplified, selective and conventional way. There are several kinds of maps: Topographic maps are general maps that show physical features (natural: relief, rivers ) and man-made features (artificial: cities, roads, crops ). - Thematic maps show information about a particular theme connected with a specific area. The most common thematic maps are: Climatic. They show information about different climates such temperature and precipitation. Political. They show political boundaries and administrative divisions of countries, cities and towns. Economic. These maps summarise information about activities such as agriculture, industry and tourism.

7 - Demographic. These maps show information about the population, for example, population density and migration. 6. GEOGRAPHICAL COORDINATES There are several major elements on a map or on a terrestrial globe: Cardinal Points. They help the orientation and can be known thanks to nature or to other artificial means, such as the compass: North, South, East and West.

Coordinates. They help find an exact point on a map through imaginary lines. The units taken for that measure are degrees (º), minutes ( ), and seconds ( ). Meridians.

8 Coordinates. They help find an exact point on a map through imaginary lines. The units taken for that measure are degrees (º), minutes ( ), and seconds ( ). Meridians. They are the imaginary lines that link the poles (they go from the north to the south or vice versa). They fix the longitude, which can be either east or west. All the meridians measure the same and there are 360 (up to 180ºE and 180ºW). In 1884 it was agreed to fix the location of the Prime Meridian (0º) in Greenwich, hence its name. It has its antipodes at 180º. Meridians fix the time zones, which are 24 in total basing on the location of each region and the sun (each time zone stretches 15º). The time we use as a reference is called Greenwich Mean Time (GMT). As we move eastwards, clocks move forward the same number of hours as time zones travelled. On the contrary, if we move westwards, clocks go back the same number of hours as time zones travelled. Parallels. They are imaginary lines that are parallel to the equator (parallel 0º). There are 180 in total (90ºN and 90ºS). They fix the latitude (north or south) and divide the world into two parts, the northern and the southern hemispheres. There are several major parallels.

9 - Equator. It is located at 0º and it separates the northern and the southern hemispheres. - Tropics. They are the imaginary lines that are the maximal point of perpendicular fall of the sun onto the Earth. They are caused due to the axial tilt. Tropic of Cancer. It is located at 23º27 N. Tropic of Capricorn. It is located at 23º27 S. - Polar Circles. They are the imaginary lines above which there is at least 24 hours of day-time or night-time in a row. They are also caused by the axial tilt. Arctic Circle. It is located at 66º33 N Antarctic Circle. It is located at 66º33 S. EXERCISES 1. What is the Milky Way? 2. How many planets are there in our Solar System? How many dwarf planets are there? 3. Match the words to the correct groups: Jupiter Milky Way Pluto planets Earth dwarf planets Ceres galaxies Saturn stars Sun Mars 4. Answer true or false and correct the wrong sentences: a. There are three dwarf planets. b. The eight planets are divided into three groups. c. The smallest planet is Venus.

5. Which planet is nearest to the Sun? Which is the furthest from the Sun? What is the Earth s position? 6. Which planet is nearest to the Earth? Which is the farthest planet from the Earth? 7.

10 5. Which planet is nearest to the Sun? Which is the furthest from the Sun? What is the Earth s position? 6. Which planet is nearest to the Earth? Which is the farthest planet from the Earth? 7. Which is the largest planet of the Solar System? And which is the smallest one? 8. Complete the sentences and choose the correct words: a. The Earth is a(n) perfect/imperfect sphere. b. The Equator divides the Earth into two equal poles/ hemispheres. c. One reason there is life on Earth is because there is liquid water/gas. d. The temperature/atmosphere protects us from harmful radiation. 9. In which hemisphere are most of the Earth s continents? 10. Look at the picture and answer the following questions: a. How many cardinal points are there? b. How can we explain the apparent movement of the Sun? c. At what cardinal point does the sun rise? 11. What season is it when both hemispheres receive the same amount of light? 12. What season is it in the north when the North Pole is tilted towards the Sun? 13. Make a drawing of the layers of the atmosphere. 14. Which atmospheric layer is being described? a. Meteorological phenomena happen here. b. It is where the ozone layer is located. c. Temperatures are very high in this layer. d. Most of the air we breathe is located in this layer. 15. How can the atmosphere protect the Earth? 16. Draw a map of the Earth and add the main parallels (Equator, Tropic of Cancer, Tropic of Capricorn, Arctic Circle, Antarctic Circle), the prime meridian, South Pole and North Pole. 17. In an atlas locate your town or city and write down what parallel and meridian it is on. 18. Match each word to one of the two concepts below: North Greenwich Tropic of Cancer

11 Longitude parallels Latitude meridians West Arctic Circle Time zones 19. In an atlas, find the geographic coordinates (latitude and longitude) of the following cities. a. Tokyo. b. New York. c. Moscow. d. Johannesburg. e. Madrid. f. Montevideo. g. Sydney. 20. In an atlas find five countries that the Equator runs through and five that the Greenwich meridian goes through. 21. Is there any place in the world at latitude 110ºN or 110ºS. If yes, say where it is. If not, explain why. 22. Only one of these names of parallels and meridians is correct. Write the others correctly. a. Tropic of Equator. b. Circle of Cancer. c. Arctic Circle. d. Meridian of Capricorn. e. Tropic of Greenwich. 23. With the help of an atlas, answer this question. What time is it in the following cities if in Greenwich it is 4 p.m.? a. Warsaw. b. Baghdad. c. Wellington. d. Lima. e. Las Palmas de Gran Canaria. 24. How many time zones are there in the world? How wide is each time zone? 25. Do all places in Spain share the same time? 26. Why is it necessary to use cartographic projections to depict the Earth? 27. What part of the world will be more distorted if we use a cylindrical projection? And if we use a conical projection? 28. Order the letters to make words from the unit: a. Mdianeri b. Lallraep c. Ltdeitua d. Itngudelo e. Uareqto f. Tpirocs g. Cphyrtogra h. Tatiroon 29. Match four of the words from the previous activity to the definitions below: a. An imaginary circle that divides the Earth into two equal halves. b. The practice of drawing maps. c. The distance between any point of the Earth s surface and the 0º meridian. d. The 24-hour movement of the Earth. 30. Answer the following questions:

12 a. What is a map? b. What are maps used for? c. How did maps emerge in the past? 31. Which is the best projection to represent...? a. The poles. b. The areas in middle latitudes. c. The world. 32. Find the following cities on the map: a. Porto Novo (32ºS, 52ºW). b. Cracow (50ºN, 20ºE). c. Castellón de la Plana (40ºN, 0ºE). d. Singapore (0ºN, 104ºE). e. Miami (30ºN, 80ºW). 33. True or false. Correct the false ones: a. There are 15 time zones of 24º each. b. In a cylindrical projection, the Earth is inscribed on a cylinder. c. It is the same time in all countries of the world. d. Aerial photography obtains images from artificial satellites. e. Numerical scale is expressed by fraction in which the numerator represents the unit on the map and the denominator expresses the real size. f. On large-scale maps, very large areas of the Earth are represented with very little detail. 34. Match each term with its definition: Rotation Longitude Meridian Latitude a. The distance, measured in degrees, from any point on Earth to the Greenwich meridian. b. The movement of the Earth around its axis. c. The distance, measured in degrees, from any point on Earth to the equator. d. The imaginary line that goes from the North Pole to the South Pole. GLOSSARY Antipodes: antipodas Asteroid: asteroide Atmosphere: atmósfera

13 axial tilt: inclinación del eje Axis: eje Boundary: frontera Cardinal Points: puntos cardinales Cartography: cartografía Comet: cometa Compass: brújula Coordinates: coordenadas Crop: cultivo Degrees: grados Detail: detalle Dust: polvo dwarf planets: planetas enanos Earth: Tierra East: este Eastwards: al este Elliptical: elíptico Equator: Ecuador Features: características Filter: filtro Flat: plano Galaxies: galaxias Gaseous: gaseoso Geoid: geoide Harmful: dañino, nocivo Hemispheres: Hemisferios inner planets: planetas interiores latitude: latitud layer: capa leap year: año bisiesto Longitude: longitud Measure: medida Meridian: meridiano Mild: suave Milky Way galaxy: galaxia Vía Láctea Model: modelo, ejemplo outer planets: planetas exteriores orbit: órbita ozone: ozono Parallels: paralelos Polar Circles: Círculos polares

14 Poles:Polos Projection: Proyección Radiation: Radiación Relief: Relieve Rocky: rocoso Rotation: rotación Scale: escala Seabed: fondo marino Seasonal: estacional Several: varios Shape: forma Sphere: esfera Star: estrella Surface: superficie Temperature: temperatura terrestrial globe: globo terrestre Topographic: topografico Tropic: trópico West: oeste Westwards: hacia el oeste Whole: entero To avoid: esquivar, evitar To belong: pertenecer a To distort: distorsionar To increase: aumentar To protect: proteger To reach: llegar, alcanzar To revolve: girar To spin, spun, spun: hacer girar, rotar To stretch: estirar To summarize: resumir To think, thought, thought: pensar

THE EARTH AND ITS REPRESENTATION

UNIT 7 THE EARTH AND ITS REPRESENTATION TABLE OF CONTENTS 1 THE EARTH AND THE SOLAR SYSTEM... 2 2 THE EARTH S MOVEMENTS... 2 2.1 Rotation.... 2 2.2 The revolution of the Earth: seasons of the year....