Earth, Moon, Sun
By: Marcie Oglesbee
Section 1 Earth in Space
How does Earth move in Space
Earth travels in two major ways, rotation and revolution.
- The spinning of Earth on its axis is a rotation. One full rotation takes 24 hours.
- The movement of one object around another is revolution. One full revolution takes 365 days.
What causes the cycle of seasons on Earth?
Earth has seasons because its axis is tilted as it revolves around the sun. If there was no axis, we would have no seasons because Earth rotates on the axis. When the north end of Earth's axis is tilted toward the sun, it's summer here in the US. When the south end of Earth's axis is tilted toward the sun, its winter here in the US.
Solstice when the sun is farthest north or south of the equator.
Equinox when the noon sun is directly overhead at the equator.
Section 2 Gravity and Motion
What determines the strength of 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.
Mass is the amount of matter in an object.
Weight is the force of gravity on an object.
Gravity attracts all objects toward each other.
What two factors combine to keep the moon and Earth in orbit?
Isaac Newton said that the 2 factors are inertia and gravity- combine to keep Earth in its orbit around the sun and the moon in its orbit around Earth.
Inertia the tendency of an object to resist a change in motion.
Newton's first law of motion states that an object at rest will stay at rest and an object in motion will stay in motion.
Section 3 Phases, Eclipses, and Tides
What causes the phases of the moon?
The changing positions of the moon, sun, and Earth causes the phases of the moon. The moon also rotates on its axis which causes the moon phases as well. The phase of the moon you see depends on how much of the sun side of the moon is facing Earth.
Phases the different shapes of the moon you see from Earth.
What are the solar and lunar eclipses?
When the moon's shadow hits Earth or Earth's shadow hits the moon, an eclipse occurs. A solar eclipse occurs when the moon passes directly between Earth and the sun, blocking sunlight from Earth. During a lunar eclipse, Earth blocks sunlight from reaching the moon.
Eclipse when an object in space comes between the sun and a third object, makes an eclipse happen.
Umbra the very darkest part of the moon's shadow.
Penumbra this larger part of the shadow
What causes the tides?
Tides that we see are most likely caused by differences in how much the moon's gravity pulls on different parts of Earth. The force of gravity pulls the moon and Earth (including water on Earth) toward each other.
Tides the rise and fall of ocean water that occurs every 12.5 hours.
Spring Tide When the gravity and sun pull in the same direction it produces a tide with the greatest difference between consecutive low and high tides.
Neap Tides a tide with the least difference between consecutive low and high tides.
Section 4 Earth's Moon
What features are found on the moon's surface?
Some of the features on the moon's actual surface are maria, craters, and highlands. Recent photos have also showed us in more detail what Galileo could see from his telescope.
Maria the dark, flat areas on the moon's surface
Craters large round pits
Highlands the light-colored features that cover much of the moon's surface
Meteoroids chunks of rock or dust from space.
What are some characteristics of the moon?
The moon is dry and airless. Compared to Earth, the moon is rather small and has large variations in its surface temperature.The moon is 3,476 kilometers in diameter. On the moon, the temperature ranges from 226 degrees Fahrenheit to -292 degrees Fahrenheit. The moons surface gravity is so weak that gases escape easily. The moon has no water at all. Some rumors say that there were ice patches near the moons poles.
How did the moon form?
The theory of the moons origin that seems to best fit the evidence is called the collision-ring theory. Scientists most think that a planet-sized object collided with Earth. Gravity caused this material to combine to form the moon.