Earth in Space and Time
E. ST.04.11 Identify the sun and moon as common objects in the sky
E. ST.04.12 Compare and contrast the characteristics of the sun moon and Earth, including relative distances and abilities to support life.
I. The sun, earth and moon
A. The sun is a star- a ball of hot glowing gasses
1. The sun appears much brighter then other stars because it is much closer to earth than other stars.
2. Because the temperatureof the sun can reach 15,000,000˚C, the sun can not support life as we know it.
3. We know that the sun rotates because scientists have seen sun spots move across the face of the sun.
4. The sun is a state of matter known as plasma, which is a special kind of gas.
B. The earth is a planet- a large body of matter revolving around the sun.
Note: The earth is mostly the solid state of matter.
1. The distance of the earth from the sun is about 93 million miles or 150 millionkilometers.
2. Many Factors make life possible on earth.
a. Earth has an atmosphere with just the right amounts of gasses including oxygen and nitrogen to support life.
b. The 23.5˚tilt of the earth on its axis creates the seasons and prevents the different parts of the earth from getting too hot or too cold.
c. Earth is ¾ covered by water.
1) Water exists in solid, liquid, and gasstates of matter on earth.
d. The gravitational pull of the mooncreates the tideswhich keep earth’s oceans from becoming stagnated and dead.
3. Because the earth and the moon revolve around the sun together, they are known as the earth moon system.
C. Moon: the earth’s natural satellite
1. The moon is only about ¼ the size of the earth and the earth is 81 times more massive than the moon.
2. The moon is 238,900 miles from the earth.
3. Water does not exist on the moon in liquid or gas forms, but small amounts of water may exist in solid form.
4. The moon does not support life as we know it.
5. The moon rotates at the same speed that it revolves. Because of this you always see the same side of the moon from earth.
6. The moon is the solid state of matter.
7. In the 1960s and 1970s NASA conducted the Apollo missions sending astronauts to the moon.
E.ST.04.21 Describe the orbit of the earth around the sun as it defines a year.
II. The earth’s revolution
A. The earth revolves around, or orbits the sun.
1. The earth revolves around the sun because of the sun’s gravitational pull.
2. One revolution of the earth around the sun is called a solar year.
a. It takes the earth 365 ¼ days to make one complete revolution of the sun.
E.ST.04.25 Describe the apparent movement of the sun and moon across the sky through day/night and the seasons.
III. The Seasons
A. As the earth revolves around the sun it is always tilted at 23.5˚ angle.
1. As the earth revolves around the sun its23.5˚tilt creates the seasons because the tilt causes different parts of the earth to receive more direct sun light at different times of the year.
a.) When the Northern Hemisphere is getting the more direct light it is experiencing summer while the Southern hemisphere is experiences winter.
b.) When the Southern Hemisphere is getting them more direct light it is experiencing summer while the Northern Hemisphere is experiencing winter.
c.) The longest day of the year is the summer solstice, and the shortest day of the year is the winter solstice.
d.) Two times a year the earth experiences equal amounts of day and night. These times are called equinoxes and they occur on the first day of spring and the first day of fall.
E.ST.04.22 Explain that the spin of the Earth creates day and night.
IV. The earth’s rotation
A. As the earth revolvesaround the sun it is also rotatingor spinning on its axis from east to west.
Note: Because the earth rotates from east to west both the sun and the moon appear to rise in the east and set in the west.
Note: Axis is the imaginary line that runs through the earth from the north to south poles
1. One rotation of the earth takes 24hours and is one day.
2. As the earth rotates the side facing the sun experiences daywhile the other side of the earth experiences night
3. The sun rises in the east because the earth rotates from westto east.
E.ST.04.23 Describe the motion of the moon around the earth.
V. The moon revolves around, or orbits the earth from west to east.
A. The earth’s gravitational pull causes the moon to orbit the earth.
B. One revolution, or orbit, of the earth takes the moonabout 27.3 days.
C. The month is based on the revolution of the moon around the earth.
E.ST.04.24 Explain how the visible shape of the moon follows a predictable cycle which takes approximately one month.
VI. The Phases of the moon.
A. It takes 27.3 days for the moon to complete one revolution around the earth.
B. The moon can be seen from earth because it reflects light from the sun.
C. The phases of the moon are caused by the position of the moon in its orbit around the earth.
1. The new moon phase occurs when the side of the moon that receives the suns light is not facing the earth.
a. The moon can not be seen during the new moon phase.
2. The first quarter phase occurs aweek after new moon when half of the moons sunlit side faces the earth.
a. The moon is waxing, which means getting bigger.
3. The full moon phase occurs two weeks after the new moon when the whole sunlit half of the moon faces the earth.
a. Full moon is the phase that shows the greatest part of the moon.
4. The last quarter phase of the moon occurs three weeks after new moon when only half the moon’s sunlit side faces the earth.
a. The moon is waning, which means getting smaller.
5. Four weeks after the new moon phase another new moon phase begins.
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