The Earth, the sun, the planets and the twinkling stars in the sky are all part of a galaxy, or family of stars. We call our galaxy the Milky Way

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2 Part One

3 The Earth, the sun, the planets and the twinkling stars in the sky are all part of a galaxy, or family of stars. We call our galaxy the Milky Way because the lights from its billions of stars look like a trail of spilled milk across the night sky.

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5 Although the sun is just a sun is a tiny speck in the Milky Way, it is the center of everything for the Earth.

6 The sun may be about 93 million miles away, but still provides the Earth with heat and light. The Earth travels around the sun in an oval-shaped path called an orbit. It takes 365 ¼ days, or one year, for the Earth to complete one revolution, or journey, around the sun.

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8 As the Earth revolves around the sun, it is also spinning in space. The Earth turns around its axis-an imaginary line running through it between the North and South poles. Each complete turn, which takes about 24 hours, is called a rotation. AS the Earth rotates, it is daytime on the side facing the sun. It is night on the side away from the sun.

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11 At certain times of the year, days are longer than nights, and at other times, nights are longer than days. This happens, in part because the Earth s axis is at an angle. At some points in the Earth s orbit, the tilt causes a region to face toward the sun for more hours than it faces away from the sun. Days are longer.

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13 At other times, the region faces away from the sun for more hours that it faces towards the sun. Days are shorter.

14 The Earth s tilt and orbit also causes changes in temperature during the seasons. The warmth you feel at any time of year depends on how directly the sunlight falls upon you. Some regions receive a great deal of fairly direct sunlight, while other regions receive no direct sunlight.

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17 1.Blow Up Your Balloon 2.Using a marker, draw the following: 1.The Equator 2.The Prime Meridian 3.North America 4.North and South Pole ***When done, wait for further directions***

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19 To understand events like volcanoes and earthquakes, you must study the Earth s structure.

20 The ground feels solid when you walk on it and downright hard if you should happen to fall. Yet Earth is not a large rock, solid shell lies a center that is partly liquid. The Earth had different layers much like an onion or orange.

21 At the center of the Earth is a dense solid core of hot iron mixed with other metals and rock. The inner core lies about 3,200 miles below the surface. Scientist think it is made up of iron and nickel. They also believe the inner core is under tremendous pressure.

22 The next layer, the outer core, is so hot that the metal has melted into a liquid. The temperature in the outer core can reach an incredible 8,500 F.

23 Surrounding, the core is the mantle, a layer of hot, dense rock about 1,770 miles thick. Like the core, the mantle has two parts. The section nearest the core is solid. The rock in the outer mantle, however can be moved, shaped, and even melted.

24 Earth s upper layer is the crust, a think rocky shell that forms the surface. It reaches only miles deep. The crust includes ocean floors and the seven continents. The crust is just a few miles thick on the ocean floor, but is much thicker below the continents.

25 The Earth s crust is not a fixed layer. It changes over time as new landforms are created and existing ones change forms. For hundreds and millions of years, the Earth s surface has been in constant motion, slowly transforming. mountains grow taller. Even continents move!

26 The theory of plate tectonics explains how the continents were formed and why they move &VIDEO=2350&CHAPTER=2&MODE=2

27 On the next slide, you see each continent sits on one or more large bases called plates. As these plates move, the continents on top of them move. This movement is called continental drift.

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29 The rate of movement varies from just under 1 inch to 7 inches per year. This movement is too slow for people to notice, but over millions of years it can have a dramatic effect.

30 One of the most drastic changes the Earth has seen due to continental drift over the millions of years is the number of continents the Earth has. =zx5a685c a000c670a&t=earth

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35 Quaternary

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37 To explain this question geographers use a theory called plate tectonics. It said the outer skin of the Earth, called the crust is broken into huge pieces called plates. It says the outer skin of the Earth, called the crust, is broken into huge pieces called plates.

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39 Forces like volcanoes slowly build up the Earth; other forces slowly break it down. Often, the forces that break the Earth down are not as dramatic as volcanoes, but the results can last just as long.

40 Weathering is a process that breaks rocks down into tiny pieces. Three things cause weathering: 1) Wind 1) Rain 1) Ice

41 Slowly by surely, they wear away the Earth s landforms. Hills and low, rounded mountains show what weathering can do.

42 The Appalachian Mountains in the eastern United States once were as high as the Rocky Mountains of the western United States. Wind and rain weathered them into much lower peaks.

43 Weathering helps create soil, too. Tiny pieces of rock combine with decayed animal and plant material to form soil. Once this breaking down has taken place, small pieces or rock may be carried to new places by a process called erosion. Weathering and erosion slowly create new landforms. ceew

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45 Story 1: In late May 1996, a tornado s furious winds tore down a movie screen of a drive-in theater in St. Catherine s, Ontario, Canada. Ironically, the week's feature movie was Twister, a movie about tornados.

46 Story 2: Richard and Daphne Thompson spend their time tracking tornados in Oklahoma. Daphne Thompson recalls one particular storm: The car was hit by 50- to 70-mile per hour gusts, she says. Tumbleweeds were blowing so hard one left a dent in the car.

47 These two stories show that weather like tornadoes can be dangerous. Or is it climate like tornadoes? What is the difference between weather and climate?

48 Weather is measured primarily by temperature and precipitation.

49 How hot or cold the air is.

50 Water that falls to the ground as rain, sleet, hail or snow.

51 Climate is NOT the same thing as weather. The climate of a place is the average weather over many years. Weather is what people see from day to day.

52 What is today s weather? What is the climate in North Carolina?

53 The Earth has many climate regions. Some are hot, some cold, and others get between feet of rain fall a year.

54 Geographers know climates are different in the low, middle, and high latitudes, because latitude affects temperature.

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56 In low latitudes, you will find two types of tropical climates. Both are hot and wet.

57 A tropical wet climate has two seasonsone with a great deal of rain and one with a little less rain.

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59 A tropical wet and dry climate also has two seasons: one with much rain and one with very little rain.

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61 The vegetation associated with these climates are tropical rain forest. Because growing conditions are so perfect-there is so much light, heat, and rain-thousands of kinds of plants grow in a rain forest.

62 Arid and semiarid climates are very hot but receive very little rain. Since there is so little moisture, vegetation in dry regions is sparse. Plants grow far apart in sandy, gravelly soil. Their shallow roots are adapted to absorb scarce water before it evaporates in the heat. Some plants have small leaves, which lose little moisture into the air through evaporation. Other plants flower only when it rains so that as many seeds survive as possible.

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64 Moderate climates are found in the middle latitudes. There are three types:

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66 The Mediterranean climate receives most of its rain in winter and summers are hot and dry.

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68 Most marine west coast climates are mountainous and are cooled by ocean currents.

69 Humid Subtropical

70 Of the three moderate climates, the humid subtropical climate has the most precipitation, heat, and humidity.

71 In all three climate types rain is moderate. There are seasonal changes, but temperatures hardly ever fall below freezing.

72 In a humid continental climate, summer temperatures are moderate to hot, but winters can be very cold. This kind of climate supports grasslands and forests.

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74 The polar climates of the high latitudes are cold all year around. The tundra, which lies along the Arctic Circle, has short, cold summers and long, even colder winters. No trees grow here.

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76 The climate at the top of Mt. Everest, in Nepal in Southeast Asia, is like Antarctica s. But Mt. Everest is near the Tropic of Cancer, far from the South Pole. Why is it so cold at the top of the mountain? A mountain is an example of a vertical climate.

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