Earth, Moon, and the Sun
By: Bailey Wood
Earth in Space
How does Earth Move?
The two ways Earth moves through space are rotation and revolution
Rotation is the spinning of Earth on its axis. The axis is the imaginary line that passes through Earth's center and the North and South Poles. Revolution is the movement of one object around another. It takes Earth 365.25 days to revolve around the sun. 365 days makes up one year and every 4 years, 366 days.
What causes the cycle of seasons on Earth?
Earth's Seasons are caused by the the tilt of Earth's axis as it revolves around the sun
The Earth is always tilted at an angle of 23.5° from the vertical.As Earth moves around the sun, the North end of Earth's tilts away from the sun for half a year, and towards it for half a year. This causes sunlight to hit the Earth more directly in some areas and less directly in others. The result of this is seasons.
Gravity and Motion
What determines the force of gravity between two objects?
The Strength of the force of gravity between two objects is dependent on their masses and the distance between them. More mass creates a stronger gravitational pull. Shorter distance creates stronger pull.
Large mass + Short distance = Strong gravitational pull
What two factors combine to keep the moon and Earth in orbit?
The combination of gravity and inertia keeps the moon in orbit around Earth.
Inertia is the tendency of an object to resist a change in motion. The moon is in motion and stays in motion. Gravity is the force that attracts objects together. Gravity pulls the moon towards Earth, and inertia keeps it in orbit.
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.
The sun is what lights the moon, however because the moon revolves around Earth, you see the moon in different angles. Half of the moon is almost always in sunlight. The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth.
As the moon continues its orbit, you see less of the lighted side, creating the phases. It takes 29.5 days for the moon to complete a cycle.
What are the solar and lunar eclipses?
Eclipses occur when moon's shadow hits Earth or Earth's shadow hits the moon.When an object in space comes between the sun and another object, it cast a shadow on that object, causing an eclipse.
A solar eclipse occurs when the moon passes between the Earth and the sun, blocking the sunlight from reaching Earth. The very darkest parts of the moon is called the umbra. Only the people within the umbra experience a total solar eclipse. During a total solar eclipse, the sky turns as dark as night and even in the middle of a day, and the air gets cool. The larger part of the moon shadow is called the penumbra. In a penumbra, part of the sun is visible from Earth. People that see part of the sun during a solar eclipse are experiencing a partial solar eclipse.
Lunar eclipses occur at a full moon when Earth is directly between the moon and the sun. During a lunar eclipse, Earth blocks the sunlight from reaching the moon. This causes the moon's shadow to look dim and sometimes red in color. The Earth also has an umbra and a penumbra. When the moon is Earth's umbra, you see a total solar eclipse. When the moon is in Earth's penumbra, you are seeing a partial lunar eclipse.
Constellation Spotting party!
Come gaze at the stars in all their beauty
What causes the tide?
Tides are the rise and fall of the ocean water. Tides are mainly caused by differences in how much the moon's gravity pulls on different parts of the Earth
The force of gravity one Earth that is closer to the moon is stronger that the Earth as a whole. High tides occur on the side of the Earth that is facing the moon. The low tides occur on the opposites of these sides.
Spring tides are tides with the greatest difference between consecutive high and low tides. During new moons, the sun, moon, and Earth in a line. The combined gravitational pull of the moon and the sun on Earth that pulls in the same direction results in a spring tide.
During the moon's first and third quarters phases, the line between Earth and the sun is at right angles to the moon's pull. This arrangement causes a neap tide. A neap tide is a tide with the least difference between consecutive low and high tides. These occur twice a month.
What features are found on Moon's surface?
The moon's surface is covered by craters, marias. and highlands.
Craters are large round pits on the moons suface. Scientists used to think these were caused y volcanic activity, however know now that they are actually caused by meteoroids.
Marias are dark faflt areas on the moon. Maria is Latin for "seas." Galileo Galilei named these areas Marias because he thought they were oceans, but they are actually hardened rock, formed from lava flows.
Highlands are are mountains on the moon. These areas are the light areas we see on the moon. The peaks of these mountains and the rims of craters cast dark shadows.
What are some characteristics of the moon?
The moon is dry and ariless. Compared to Earth, the moon is small and has a large variation in temperture.
The moon is 3,476 kilometrs in diameter. The moon's average density is close to the density of Earth's outer layers.
In direct sunlight, the moon reaches 130°C (266°F) and -180°C (-292°F) at night. These temperatures vary so much because the moon has no atmosphere.
There is no liguid water on Earth, but there is evidence that shows that there may be patches of ice near the moon's poles. Because some areas are shielded from the sunlight by crater walls, these regions remain freezing.
How did the moon form?
Many different scientific theories have been suggested to explain how the moon formed. The theory of the moon's origin that best fits the evidence is called the collision-ring theory. About 4.5 billion years ago when Earth was very young, the solar system was full of debris. Some of them even the size of small planets. Scientists theorize that a planet-sized object collided with Earth to form the moon. Then material from the object and Earth's outermost layers were ejected into orbit around Earth, forming a ring.