Earth, Moon, and Sun
by: Mac Snyder
Earth In Space
How Does the Earth move in Space?
The Earth rotates on its axis, which is the imaginary line that passes through Earth's center through the North and South poles. The Axis is at a 23.45 degree tilt. The Earth also orbits around the Sun at about 18.5 miles per second. It takes 24 hours for Earth to completely rotate and 365.25 days for the Earth to completely orbit the Sun.
What Causes the Cycle of the Seasons?
As the Earth moves around the sun, the Axis always points in the same direction. This causes uneven distribution of the suns rays. During December, January, and February the southern hemisphere is pointed toward the sun making it summer in the Southern hemisphere and Winter in the Northern hemisphere. During June, July, and August the Northern hemisphere is pointed toward the sun making is summer there and winter in the southern Hemisphere. during the other six months neither hemisphere is pointed toward the sun making it spring or fall.
Gravity and Motion
What Determines the Strength of the Force of Gravity between Two Object?
Mass and distance determine the strength of gravity between objects. Objects with higher masses will have a stronger gravitational pull. Objects with less mass will have a weaker gravitational pull. Distance also helps determine the strength of gravity. Objects that are far away from each other will have a weak gravitational pull towards each other. Objects with a short distance between them will have a greater gravitational pull.
What Two Factors Combine to Keep the Moon and the Earth in Orbit?
The two factors that keep earth and moon in orbit are inertia and gravity. Inertia is the tendency of an object to resist change in motion. The moons orbital motion is caused by the combined forces of gravity and inertia.
Phases, Eclipses, and Tides
What causes the Phases of the Moon?
The phases of the moon are caused by the relative positions of the moon, Earth, and sun. The moon reflects the Sun's light. the Amount of reflected light we see causes the phases.
What are Solar and Lunar Eclipse?
A solar eclipse happens when the Moon blocks the view of the Sun. During a solar eclipse the umbra, or darkest part of the moons Shadow is on earth. A lunar eclipse happens when the earth is directly between the moon and the Sun. This causes the Umbra of the Earth to be over the moon.
What Causes the Tides
Tides are caused by the differences in the gravitational pull on Earth. High tide lasts for about six hours and low tides last for about six hours. Spring tides is when there is an unusually high tide. This is rare and only happens when the moon is closest to earth. Neap tides occur when there is the least difference between low and high tides. This happens twice a month.
What Features are Found on the Moons Surface?
There are three main features of the moons surface. They are maria, craters, and highlands. Maria is the Latin word for sea. When Galileo looked at the moon, he incorrectly thought these dark areas formed from hardened lava flows where oceans and seas. Craters are also land forms of the moon. Craters are formed from meteoroid impacts. there are thousands of craters on the moon. Highlands are also a land form on the moon. Galileo also saw light spots on the moon and correctly inferred that these spots where mountains and highlands.
What are Some Characteristics of the Moon?
The moons diameter is 3476 kilometers which is about 1/4 of Earths diameter. The moon has 1/18 of Earths mass. The temperature on the moon ranges from 130 degrees C to -180 degrees C. The atmosphere and gravity on the moon is very weak. The moon has no liquid but there is evidence of ice in the polar regions.
HOw Did the Moon Form?
There are many possible theories on how the moon was formed. One theory that fits the evidence is that while Earth was still young a small planet collided with it sending molten rock into space. This rock came together. As this rock cooled it got stuck in Earths gravitational pull and became the moon!
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