Earth, Moon, and Sun
By Nicole Johnson
Section 1-Earth In Space
How does Earth move in space?
Earth moves in space by two ways which are rotation and revolution. In rotation, the earth spins on its axis (imaginary line that passes through the center of Earth).The next way is revolution. Revolution is the movement of one object around another, just like Earth travels around the sun. It takes Earth one year to revolve around the sun.
What causes the cycle of seasons on Earth?
The reason Earth has seasons at all is because its axis is tilted as it revolves around the sun. The seasons of summer and winter are caused by Earth's tilt as it revolves. The side of the Earth tilted toward the sun is the one with more direct sunlight, making it warmer. The side of Earth tilted away gets less direct sunlight, which makes it colder.
Section 2- Gravity and Motion
What determines the strength of the force of gravity between two objects?
The strength depends on two factors. These factors are the masses of objects and the distance between them. When mass increases, force, or gravity, increases. The heavier an object, the more gravitational pull. With distance, the further apart the objects are, the gravity decreases. So when objects are further apart they will have less gravity towards each other then objects further apart.
What two factors combine to keep the moon and Earth in orbit?
Inertia and gravity combine to keep the Earth and the moon in orbit. Earth's gravity helps to pull the moon toward it, so that it doesn't move in a straight line. While this is happening, so is inertia. Inertia helps the moon keep moving in the same motion as opposed to moving in a straight line.
Section 3- Phases, Eclipses, and Tides
What causes the phases of the moon?
The phases of the moon are caused by changes in the positions of the moon, Earth, and sun. As the moon revolves around the Earth you see it at different angles, while the sun is lighting the moon.
What are solar and lunar eclipses?
An eclipse is caused when the moon's shadow hits Earth or Earth's shadow hits the moon. A solar eclipse is an eclipse that occurs when the moon passes directly between Earth and the sun, blocking sunlight from Earth. A solar eclipse happens when a new moon blocks your view of the sun. A lunar eclipse happens when Earth blocks sunlight from reaching the moon. Lunar eclipses only happen when there is a full moon. There are two types of each eclipse: total and partial.
What causes the tides?
Tides are caused by differences in how much the moon's gravity pulls on different parts of Earth. There are always two low tides and two high tides. The side closest to the moon will experience a high tide because there is more force. Also, on the opposite side of the Earth there will be a high tide because the force of moon's gravity pulls Earth toward the moon, leaving water behind. There are two types of tides: a spring tide and a neap tide.
Section 4- Earth's Moon
What features are found on the moon's surface?
Features on the moon's surface include maria, craters, and highlands. Maria are dark, flat areas on the moon formed by hardened rock from lava. Craters are large round pits caused by the impacts of meteoroids, which are chunks of rock or dust from space. Highlands are peaks or mountains. The peaks of the lunar highlands and the rims of the craters cast dark shadows.
What are some characteristics of the moon?
The moon is very different compared to Earth. First, the moon is dry and airless and has no atmosphere. The moon has very weak surface gravity. The moon has only one eightieth as much mass as the Earth. Also, the moon has no liquid water but it does have ice.
How did the moon form?
Most scientists believe in the collision-ring theory. The collision-ring theory says that about 4.5 billion years ago, the solar system was full of debris, and a planet-sized object collided with the Earth to from the moon.