Earth

For year's man have studied the earth and the atmospheres to understand how life only exists on earth. There are many factors that have to work together in order for this to happen. The study of the earth and its structure is called Geology. Earth is the third planet from the sun and the fifth largest. Planet earth is only a tiny part of the universe. Earth is the only planet whose English name does not derive from Greek/Roman mythology. Earth is the densest major body in the solar system.

The crust is quite thin, is about 22 miles thick and beneath the continents and about only 3 miles thick beneath the ocean. Its thickness beneath the mountain is about 40 miles thick. The inner core and mantle are plastic. The mantle is the middle layer of the earth. It is about 1800 miles thick and makes up the largest portion of the earths interior. Between the crust and the mantle there is a boundary called the Moho? The Moho was discovered by the creation geologist. Like the crust, the mantle is made of solid rock.

Beneath the mantle lays the core which is the inner most region of the earth. The core exists from the bottom of the mantle all the way to the center of the earth which is about 4000 miles beneath our feet. Unlike the rock of the crust and mantle the core is composed of dense metal like iron and nickel. The earth core is divided into 2 sections the outer core and the inner core. The outer core is white hot and consists of melted iron and nickel. The inner core is a mass of even hotter metals, but it remained solid instead of a liquid because upon me a ball of metal ties at the center of the ear, and half between the north and South Pole it is an imaginary circle around it called the equator. The earth is not exactly rounding, but slightly flattened at poles. At the plus the earth measures 24901 and 55 miles, it takes an astronaut 90 minutes to circle the earth in space, but two days for a fob airplane o circle the earth.

Planet earth is always constantly moving. It spins like a top and travels around the sun at the same time. These two motions of earth are to be measured by the length of day and years. One day it is the result of time it takes the earth. One year is the result in the time it takes the earth to be gravel. One day is the result of the time it takes the earth to revolve around once. One year is the time it takes the earth to travel around the sun. Earth and Pluto are the only planets that have one moon traveling around it. The spinning motion makes the sun appear east to west, and day and night on the earth. It takes approximately 25 hours, 56 minutes, and 409 seconds for the earth to spin around once. The earth travels 595 million miles around the sun in 365 days. In this time earth travels 66,600 miles an hour.

Earths air is called atmosphere. Nitrogen makes up 78 percent of the atmosphere, and oxygen makes up 21 percent. The remaining 1 percent consists mainly of argon and small amount of other gasses. Atmosphere also contains water vapor, carbon dioxide, water droplets, dust particles, and small amount of many other chemicals released by volcanoes, fires, living things, and human activities. Floods float in the lowest part of the atmosphere, wind, storm, and other weather take place in the troposphere, about 30 miles above the earths surface, it's a layer of still air called the stratosphere, the stratosphere contains a layer where ultraviolet light from the