5 Today we know that the Earth rotates, or spins, not the sun Today we know that the Earth rotates, or spins, not the sun. This spinning causes day and night. It is the reason that the sun seems to rise, move across the sky, and then set.
8 Have you ever been on a merry-go-round Have you ever been on a merry-go-round? It turns around a pole in its center. Earth is like a giant merry-go-round, but the pole is imaginary. This imaginary pole is called Earth’s axis.
10 How long does it take for the Earth to complete one full rotation? Rotation is counterclockwisewhen viewed from the North Pole.
11 The axis runs through Earth’s center, from the North Pole to the South Pole. Earth rotates on its axis once about every 24 hours.South Pole
12 The axis is not at a 90 degree angle The axis is not at a 90 degree angle. The Earth’s axis is tipped over at an angle of 22.5 degrees. This is why we experience seasons.22.5South Pole
13 As Earth rotates, only one side of it faces the sun As Earth rotates, only one side of it faces the sun. This part of Earth is having daytime. The other side of the Earth faces away from the sun and is having nighttime. As the Earth rotates, we have day and night over and over again and again.
14 What is responsible for Americans having daytime while it is nighttime in Australia?
15 The time it takes a planet to rotate once on its axis is 1 full day The time it takes a planet to rotate once on its axis is 1 full day. The rate of rotation is different for each planet, so each planet has a different number of hours in one of its days. One Earth day = 24 hours.
16 The Earth rotates on its axis from WEST to EAST The Earth rotates on its axis from WEST to EAST. It takes 24 hours for the Earth to make one complete rotation on its axis.EW
17 It is revolving. As the Earth continually rotates on its axis, tilted over at about 23degrees, it is also moving inanother way.It is revolving.To revolve is to follow a patharound the sun.
19 Earth takes about 365 days to make one complete orbit around the sun Earth takes about 365 days to make one complete orbit around the sun. As Earth moves around the sun, Earth’s axis stays tilted in the same direction. The tilt of Earth’s axis plus its orbit causes the seasons.
20 The path that the Earth travels on is called its orbit The path that the Earth travels on is called its orbit. Earth’s orbit around the sun follows the same path.N
22 But not every planet has the same number of hours in their day But not every planet has the same number of hours in their day. Some planets have shorter days while others have longer days. The amount of time it takes the planet to complete one full rotation determines the length of each planet’s day.
24 Earth is divided into halves called hemispheres Earth is divided into halves called hemispheres. The upper half is the Northern Hemisphere. The lower half is called the Southern Hemisphere.
25 The hemispheres are divided into halves by the imaginary line called the Equator. Equa = Equal Hemi = Half
26 There is also the Western Hemisphere and the Eastern Hemisphere There is also the Western Hemisphere and the Eastern Hemisphere. The Earth is cut in half from North to South.
27 Because of the tilt of the Earth, the Northern Hemispheres is tilted toward the sun during the summer months and gets more rays of sunlight. There are also more hours of daylight and it’s warmer. Summer is here.
29 When it is summer in the Northern Hemisphere, the opposite season is occurring in the Southern Hemisphere. The Southern Hemisphere is tilted away from the sun and gets less sunlight. There are fewer hours of daylight, and it’s cooler. It is winter.
30 In December, the Northern Hemisphere is tilted away from the sun In December, the Northern Hemisphere is tilted away from the sun. It’s winter now. At the same time, the Southern Hemisphere is tilted toward the sun. Now it’s summer in the Southern Hemisphere.
31 PATTERNS in the SKY For thousands of years, people have seen pictures in the stars. They connect the stars to make a pattern or a shape. This is the Big Dipper.
33 Star patterns are called constellations Star patterns are called constellations. Constellations are groups of stars that seem to form a pattern in the night sky. The early Greeks named constellations after animals or people from stories called myths.
34 The Big Dipper is part of a constellation called Ursa Major, or The Great Bear. Orion is a constellation named after a hunter in a Greek myth.
35 As Earth rotates on its axis, constellations seem to move across the night sky. Like the sun, constellations seem to rise in the east and set in the west. Stars above the North Pole, don’t seem to move as much. They move in a circle.
36 The positions of the constellations seem to change with the seasons The positions of the constellations seem to change with the seasons. This is because we see different parts of space as Earth revolves around the sun. Stars do change over time, but it will take millions of years for a constellation to change its shape.
37 Show What You KnowDay and night are caused by Earth’s ______________________.2. Earth revolves around the sun once every _____________________.3. Earth’s seasons are caused by Earth’s revolution and _____________.During winter in the Northern Hemisphere, there are _______________________ and it is _____________.5. When it is spring in the Northern Hemisphere, it is ______________in the Southern Hemisphere.6. Constellations appear to move across the night sky because of Earth’s___________________________.
39 Earth Earth number 3 - Earth the perfect home for me! M-V-E-M-J-S-U-N(P - Little Pluto doesn’t count any more )
40 MERCURY Mercury is the closest planet to our sun. It’s only 36 million miles from our sun.Mercury orbits the sun every 88 days andspins or rotates on its axis every 59 days.
41 Mercury is the smallest planet in our Solar System. It is about the size of our moon.Mercury has no moons or natural satellitesof its own.There is very little atmosphere because ofthe limited gravitational force.The gravitational force is about 1/3 of Earth.
42 It can reach 450 degrees C ( 840 degrees F) Mercury is extremely hot during the day because it is so close to the sun.It can reach 450 degrees C ( 840 degrees F)during the day and then plummetto degrees C ( -275 degrees F) at night.Mercury is very similar to Earth incomposition. It has a very rocky surfaceand an iron core.
43 MERCURY Roman god of commerce, travel and thievery Mercury Mercury number 1! Mercury closest to the sun.
44 Venus is the 2nd planet from our sun. It is located between Mercury and Earth,about 47 million miles from our sun.Venus orbits the sun every days.It spins or rotates on its axis around thesun every days. So each day is longerthan its year.
45 Venus rotates east to west instead of west to east, like on Earth. Venus is called our “sister planet” becauseit is almost the same size as Earth.Venus has no natural satellites or moons.The atmosphere is 95% carbon dioxide.There is no magnetic field on Venus.
46 Venus is covered with thick clouds which hold in the heat. (greenhouse effect)Temperatures range from about500 degrees C (900 degrees F)to -32 degrees C (-50 degrees F).Venus has a rocky, waterless surface with mountains, canyons, plains, and a milelong river of hardened lava.
47 VENUS Roman god of love and beauty Venus Venus number 2. Too hot for me – too hot for you!
48 EARTH Earth is the 3rd planet from our sun. It is located 93 million miles from the sun.Earth orbits our sun about every days,travelling at more than 67,000 mph.Earth spins or rotates on its axis every24 hours.
49 Earth 5th largest of all the planets. It has one natural satellite, our moon.The atmosphere is gaseous consisting of78% nitrogen and 21% oxygen.Earth’s gravity is9.8 meters per second squared.Strong enough to keep us fromfloating away.
50 Over 71% of Earth is covered in water! Allowing life to flourish. The coldest temperature ever recorded was 89 degrees C (-128 degrees F).The hottest temperature was58 degrees C ( 136 degrees F).
51 EARTHEarth Earth number 3! Earth the perfect home for me.
52 MARS Mars is the 4th planet from our sun. The surface can be seen in detail from Earth.Mars is located 228 million km from our sun.It takes days to make a full orbitaround the sun and it spins or rotatesevery hours.
53 Mars is half the size of Earth. It is the 2nd smallest planet in our Solar System.The atmosphere is 95% carbon dioxide.The gravity is about 1/3 of Earth’s.
54 The temperature ranges from -140 degrees C (-220 degrees F) to Mars has a hard rocky surface.You can walk on Mars.It is covered with dry red dust.Mars has 2 permanent polar ice caps.
55 MARSThe red planet.Mars Roman god of war. Mars Mars number 4!
56 JUPITER Jupiter is the 5th planet and is over 466 million miles away from our sun.It takes 12 years for Jupiter to completeone orbit around the sun.It takes 10 hours for Jupiter to spin orrotate on its axis.
57 Jupiter is the largest of all the planets in our Solar System. At this time, 67 moons have beendiscovered.The atmosphere consists of hydrogenand helium.Jupiter is a giant ball of gas.Temperatures range from-163 degrees C to 121 degrees C.
58 Jupiter Jupiter number 5 Jupiter largest in the sky.
59 SATURN Saturn is the 6th planet in our Solar System. It is most remembered for the rings thatsurround it.It takes 29+ years to make one completeorbit around our sun.It takes 11 hours to spin or rotate onits axis.
60 Saturn is the second largest planet. It is 10 times the size of the Earth.Saturn has at least 62 moons.The atmosphere is made of hydrogenand helium gases.Saturn is the windiest of all the planets.
61 Saturn average temperature is -178 degrees C. It is composed of liquid and gas.The famous rings aremade of ice crystals.Saturn was named for the Roman godof agriculture.
62 SATURNSaturn SaturnNumber 6.Saturn is thewindiest!
63 URANUS It is located 1,783,939,400 miles from the sun or 19.2 AU. It takes 84 years to orbit the sun.It spins on its side at 98 degrees andit also spins backward.It takes 17 hours to complete one rotation.
64 Uranus is the 7th planet and is the third largest planet in our Solar System.It has 27 satellites.The atmosphere consists of 83% hydrogenand 15% helium.
65 The average temperature is -197 degrees C or -323 degrees F. Uranus is a gas giant.There is no solid surface on Uranus.Uranus is surrounded by ringsand gets its blue green color frommethane gas.
66 URANUSGreek god ofthe sky.Uranus flippedover on its side.
67 NEPTUNE Neptune is called a Blue Giant. It is located billion miles from our sun.It takes years to complete one orbit.It takes 16 hours to spin or complete one rotation on its axis.
68 Neptune has 13 known satellites. Its atmosphere consists of 74% hydrogen,25% helium, and 1% methane.Neptune is tipped on its axis at 28 degreesso it has seasons.It is composed of gas and has rings.
69 NEPTUNERoman godof the sea.Neptunenumber 8 for me.
70 PLUTO Poor little Pluto is no longer considered one of the planets in our Solar System. It has been demoted to a “Dwarf Planet”.
71 It takes Pluto 6 days to spin or rotate on its axis It takes Pluto 6 days to spin or rotate on its axis. It takes 248 years for Pluto to complete one orbit around the Sun. Pluto is about half the size of Mercury and has 5 known moons.
72 Pluto’s average temperature is -233 degrees C or -382 degrees F Pluto’s average temperature is -233 degrees C or -382 degrees F. Pluto is composed of nitrogen, carbon monoxide, methane, and water ices. Pluto was named by an 11 year old girl for the Roman god of the Underworld.
76 The moon is Earth’s satellite The moon is Earth’s satellite. A satellite is an object that moves around another larger object in space. Earth’s moon is the largest and brightest object in the night sky. It looks large because it is close to Earth. But the moon is small compared to Earth.
77 The Earth’s moon is a natural satellite The Earth’s moon is a natural satellite. The moon doesn’t have any light of its own. The light we see is sunlight that hits the moon and is reflected back to Earth.
79 The moon has no air, no wind, and no liquid water The moon has no air, no wind, and no liquid water. The moon is about 1/4th the size of Earth. The pull of Earth’s gravity keeps the moon in its orbit around Earth.
80 We can only see one side of the moon from Earth We can only see one side of the moon from Earth. That is because the moon takes the same amount of time to rotate once around the Earth as it does to orbit the Earth once.
82 We can see the moon at night and sometimes during the day We can see the moon at night and sometimes during the day. The surface of the moon has been been transformed as rocks and debris slammed into it and formed craters.
83 There are mountains and large, flat plains on the moon. The flat plains on the surfaceare called maria (mah REE uh) whichis a Latin word meaning “seas.”
85 Each time you look at the moon it looks differently Each time you look at the moon it looks differently. One night it may be a tiny sliver. Several nights later you might see a bright round circle.
86 As Earth orbits the sun, the moon also orbits Earth As Earth orbits the sun, the moon also orbits Earth. The moon reflects light from the sun. That is the light we see from Earth. As the moon travels in its orbit, different amounts of the moon’s lit side can be seen from the Earth.
87 The moon’s shape does NOT change. But the appearance of the moon does The moon’s shape does NOT change. But the appearance of the moon does. These changes in appearance are known as moon phases.
89 You know that sunlight reflects from the moon to Earth You know that sunlight reflects from the moon to Earth. Yet the sun lights only half of the moon at any given time. The motions of Earth and the motions of the moon are responsible for the moon phases you see.
90 As the moon revolves around the Earth, the amount of the lit part that we see from Earth changes. These different amounts of the moon’s lighted side are the different phases of the moon. Each phase of the moon has a different shape. It takes about 1 month for the moon to complete all of its phases. This cycle repeats over and over again and again.
91 The lit portion grows larger until we see a full moon The lit portion grows larger until we see a full moon. This happens when Earth is between the moon and the sun.
92 As the moon continues in its orbit, we see less and less of its lit portion. When it is half lit again, it is a third quarter moon.
94 For thousands of years, people used the phases of the moon to make calendars and track time. Earth’s orbit around the sun also has been used to make calendars and track time. These are called solar calendars.
95 Our modern calendar is based on Earth’s orbit around the sun Our modern calendar is based on Earth’s orbit around the sun. Each month is based roughly on the moon’s phases. Once in a while, there are two full moons in one month. This is called a “ blue moon.”
96 The Aztec calendar is based on Earth’s orbit around the sun The Aztec calendar is based on Earth’s orbit around the sun. Each part of the calendar has colorful animals or symbols. These symbols marked important times of the year, such as when to plant crops.
98 People have always looked up at the night sky People have always looked up at the night sky. Early people built monuments based on what they saw in the sky. When writing was developed, people began to record their observations.
99 Early Aztec and Egyptian astronomers were limited to observing space with just their eyes. They observed several planets using just their eyes. Early astronomers also believed that Earth was the center of the universe.
100 In the 1600’s the telescope was invented In the 1600’s the telescope was invented. A telescope is a tool that uses lenses to make faraway objects appear closer and larger. Galileo was one of the first astronomers to study space by using a telescope.
101 The telescope led to many new observations about space The telescope led to many new observations about space. Galileo observed four of Jupiter’s moons by using the telescope.
102 By the early 1600s, astronomers knew that the Earth revolved around the sun.However, they still believed thatthe sun was the center ofthe universe.
103 EXPLORATION Space probes are vehicles that move through space, but are controlled from Earth. Observatories have been built all over the world to observe distant stars.
104 The launch of Sputnik was the beginning of the Space Age The launch of Sputnik was the beginning of the Space Age. The Gemini 7 space capsule took two astronauts on a 14-day orbit around Earth.size of abeach ball
105 “That’s one small step for man, and one giant leap for mankind “That’s one small step for man, and one giant leap for mankind.” Neil Armstrong spoke those words from the moon’s surface in July of He was the first person ever to set foot on the moon.
107 Astronauts have lived on the International Space Station Astronauts have lived on the International Space Station. The International Space Station is a giant space lab that orbits Earth. Astronauts orbited Earth in the Space Shuttle, too. The Hubble Space Telescope is another example of technology in space.
108 The Hubble Space Telescope takes pictures of faraway galaxies.
112 Florida has had a major role in the exploration of space Florida has had a major role in the exploration of space. The space age began in Florida in the early 1960s. Florida’s space center was called Cape Canaveral. Each of the moon missions launched from Florida’s east coast. NASA renamed the space center in honor of Presidents John F. Kennedy in 1963.
114 The space race has affected the economy and the culture of Florida The space race has affected the economy and the culture of Florida. Many people work at the Kennedy Space Center. Engineers design and build rockets. Scientists study data. Astronauts train for space flight. Tourists visit the Kennedy Space Center to see and experience the wonders of space.
118 Our lives are different today because of space exploration Our lives are different today because of space exploration. Many things that were invented to benefit the astronauts and the space program have directly impacted our lives.
119 Satellites relay TV and phone signals across the world Satellites relay TV and phone signals across the world. Communication is now world wide.
120 Benefits from space technology are called “spin-offs.” Coolers are basedon a space cooling system.They also invented freeze-driedfoods.Scientists developedcordless power tools.Astronauts needed boots towalk and jump on the moon.Today’s athletic shoes arebased on moon boots.They alsoinventedTeflon.Non stick.Race cardrivers’ suitsare spin-offsof space suits.
121 Show What You Know A person who studies space is an ________________. Name of an early astronomer is __________________.A cordless power tool is an example of ___________.___________________ was the first satellite in space.5. The _______ is a large telescope that orbits in space.6. A ____________ is a vehicle that moves through spacebut is controlled from Earth.7. A tool that is used to make objects appear larger iscalled a _______________________.8. ____________________ is the space center in Florida.