Earth, Moon, & Sun Presentation
By: Graci Skala
Section 1: Earth In Space
How Does Earth Move In Space?
Earth moves through space in two major ways:rotation and revolution. Earth's rotation causes day and night. As Earth rotates eastward, the sun appears to move westward across the sky. As earth continues to turn to the east, the sun appears to set in the west. When the earth isn't facing the sun it is night. Revolution is when the Earth travels around the sun. One complete revolution around the sun is called a year. Earth follows a path, or orbit, as it revolves around the sun. Earth's orbit is not quite circular, it is a slightly elongated circle, or ellipse.
What Causes the cycle of seasons on Earth?
Earth has seasons because its axis is tilted as it revolves around the sun. Earth's axis is always tilted at an angle of 23.5 degrees from the vertical. As earth revolves around the sun, the north end of its axis is tilted and from the sun for a little bit of the year and tilted toward the sun for the other part of the year. Summer and Winter are caused by Earth's tilt as it revolves around the sun. The change in seasons isn't caused by changes in Earth's distance from the sun. When it is summer in the Northern Hemisphere the Earth is farthest from the sun.
Seasons- Summer(usually June)- The northern end of Earth's axis is tilted toward the sun. It is summer in the Northern Hemisphere and winter in the Southern Hemisphere.
Winter(usually December)- The southern end of Earth's axis is tilted towards the sun. It is summer in the Southern Hemisphere and Winter in the Northern Hemisphere.
Fall and Spring(usually March & September)- Neither end of Earth's axis is tilted toward the sun. Both Hemispheres receive the same amount of energy.
Section 2: Gravity and Motion
What determines the strength of the force of gravity between two objects?
The strength of the force of gravity between two objects depends on two factors:the masses of the objects and the distance between them. The force of gravity decreases rapidly as distance increases. One example, is that if the distance between two objects were doubled, the force of gravity between them would decrease to one fourth of its original value.
What two factors combine to keep the moon and Earth in orbit?
Issac Newton concluded that there are two factors that can combine together to keep Earth in orbit around the sun and the moon in orbit around Earth, those two factors are inertia and gravity. Earth's gravity keeps pulling the moon toward it, this prevents the moon from moving in a straight line. A the same time, the moon keeps moving ahead because of its inertia. If not for Earth's gravity, inertia would cause the moon to move off through space in a straight line. In the same way, Earth revolves around the sun because the sun's gravity pulls on it while Earth's inertia keeps it moving back.
Section 3: Phases, Eclipses, and Tides
What causes the phases of the moon?
The changing relative positions of the moon,Earth,and sun cause the phases of the moon,eclipses, and tides. Phases are caused by changes in the relative positions of the moon, Earth, and the sun. But because the sun lights the moon, half of the moon is almost always in the sunlight. However you see the moon from different angles because the moon revolves around the earth. So, the half of the moon that faces Earth is not always the half that is sunlit. The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth.
What are solar and lunar eclipses?
The words Solar and lunar come from the Latin words, Sun and Moon.
Solar Eclipses- Occurs when the moon passes directly between Earth and the sun, blocking sunlight from Earth.
Total Solar Eclipse- During the short period of a total solar eclipse, the sky grows as dark, as night even in the middle of a clear sunny day. Also the air gets cold and the sky becomes an eerie color.
Partial Solar Eclipse- During a solar eclipse, people in the penumbra(Shadow) see only a partial eclipse. Since an extremely bright part of the sun still remains visible, its not safe to look directly at the sun.
Lunar Eclipse- During a lunar eclipse, Earth blocks sunlight from reaching the moon. Then moon is then in Earth's shadow and looks dim from Earth.
Total Lunar Eclipses- Can be seen anywhere on Earth as long as the moon is visible. You are more likely to see a total Lunar eclipse than a total solar eclipse.
Partial Lunar Eclipse- A partial lunar eclipse occurs when the moon passes partly into the umbra of Earth's shadow. But the edge of the umbra appears blurry, and you can watch it pass across the moon for two or three hours.
What causes tides?
Tide- the rise and fall of the ocean water that occurs every 12.5 hours. Tides are caused mainly by differences in how much the moon's gravity pulls on different parts of earth.
High Tide- The moon's gravity causes high tide on the side closest to the moon. The force of the moon's gravity pulls earth toward the moon, leaving the water behind.
Low tide- Low tides occur between the two high tides.
Section 4 Earth's Moon
What feature's are found on the moons surface?
The features on the moon's surface are maria, craters, and highlands.
Maria- Maria's are dark,flat areas, this was the Latin word for seas. The Maria's are actually hardened rock formed from huge lava flows that occurred between 3 and 4 billion years ago.
Craters- Craters are round large pits on the moon's surface. The craters were caused by the impacts of meteoroids, chunks of rock or dust from space.
Highlands- Highlands were also called mountains, on the moon's surface. The peaks of the lunar highlands and the rims of the craters cast dark shadows, which Galileo could see.The rugged lunar highlands cover most of the moon's surface.
What are some characteristics of the moon?
The moon is dry an airless, compared to Earth, the moon is small and has large variations in its surface temperature. Some characteristics of the moon are size, density, temperature, atmosphere, and water.
Size and Density- The moon is 3,476 kilometers in diameter, a little less than the distance across the United States. The moon has only one- eightieth as much mass as Earth. Earth has a very dense core, its outer layers are less dense though.
Temperature and Atmosphere- On the moon's surface, temperatures range from a torrid 130 degrees Celsius in direct sunlight and down to -180 degrees Celsius at night. Moon has no atmosphere so temperatures vary. Gases on the moon can easily escape into space because gravity is so weak.
Water- The moon has no liquid water, but there is evidence that there may be large patches of ice near the moon's surface. One reason is because there are some areas that are shielded by sunlight because of crater walls.
How did the moon form?
The theory of the moon's origin that best fits the evidence is called collision-ring theory. About 4.5 billion years ago, when Earth was very young, the solar system was full of rocky debris. Scientist theorize that a plant-sized object collided with Earth to form the moon. Material from the object and Earth's outer layer was ejected into orbit around Earth, where it formed a ring. Gravity caused this material to combine to form the moon.