1. Earth’s Atmosphere

2.  The three main features of the Earth are the land, the water and the air.  Land areas include the seven continents and other landmasses. Scientists call all the land on Earth the lithosphere – “rock sphere”.

3. The water on Earth makes up the hydrosphere (hydro means water). About 97% of Earth’s water is salt water leaving only 3% fresh water. Of the 3% of Fresh water nearly 85% is trapped in ice. The water on Earth makes up the hydrosphere (hydro means water). About 97% of Earth’s water is salt water leaving only 3% fresh water. Of the 3% of Fresh water nearly 85% is trapped in ice. The oxygen that you breathe is found in the last great sphere that makes up planet Earth, the atmosphere. The atmosphere is the envelope of gases that surrounds the Earth. The oxygen that you breathe is found in the last great sphere that makes up planet Earth, the atmosphere. The atmosphere is the envelope of gases that surrounds the Earth. About 3.8 billion years ago, chemical reactions triggered by sunlight produced new substances in the atmosphere. About 3.8 billion years ago, chemical reactions triggered by sunlight produced new substances in the atmosphere.

4. The ozone layer is sometimes referred to as an “umbrella” for life on Earth. The ozone layer absorbs much of the harmful radiation from the sun. The ozone is made up of atoms of oxygen. The ozone layer is sometimes referred to as an “umbrella” for life on Earth. The ozone layer absorbs much of the harmful radiation from the sun. The ozone is made up of atoms of oxygen. Today, the atmospheric gases include nitrogen – 78%, oxygen – 21%, less than 1% of [carbon dioxide, water vapor, argon, and trace gases (neon, helium, krypton, and xenon)]. Today, the atmospheric gases include nitrogen – 78%, oxygen – 21%, less than 1% of [carbon dioxide, water vapor, argon, and trace gases (neon, helium, krypton, and xenon)]. Gravity is a force of attraction by which objects are pulled toward each other. Because of gravity, the layers of air surrounding the Earth push down on the Earth’s surface. This push is called air pressure. Gravity is a force of attraction by which objects are pulled toward each other. Because of gravity, the layers of air surrounding the Earth push down on the Earth’s surface. This push is called air pressure.

5. The four main layers of the atmosphere are the troposphere, stratosphere, mesosphere, and the thermosphere. The four main layers of the atmosphere are the troposphere, stratosphere, mesosphere, and the thermosphere. Almost all of the Earth’s weather occurs in the troposphere. Almost all of the Earth’s weather occurs in the troposphere.

6. The ozone layer is sometimes referred to as an “umbrella” for life on Earth. The ozone layer absorbs much of the harmful radiation from the sun. The ozone is made up of atoms of oxygen. The ozone layer is sometimes referred to as an “umbrella” for life on Earth. The ozone layer absorbs much of the harmful radiation from the sun. The ozone is made up of atoms of oxygen. Today, the atmospheric gases include nitrogen – 78%, oxygen – 21%, less than 1% of [carbon dioxide, water vapor, argon, and trace gases (neon, helium, krypton, and xenon)]. Today, the atmospheric gases include nitrogen – 78%, oxygen – 21%, less than 1% of [carbon dioxide, water vapor, argon, and trace gases (neon, helium, krypton, and xenon)]. Gravity is a force of attraction by which objects are pulled toward each other. Because of gravity, the layers of air surrounding the Earth push down on the Earth’s surface. This push is called air pressure. Gravity is a force of attraction by which objects are pulled toward each other. Because of gravity, the layers of air surrounding the Earth push down on the Earth’s surface. This push is called air pressure.

7. The four main layers of the atmosphere are the troposphere, stratosphere, mesosphere, and the thermosphere. The four main layers of the atmosphere are the troposphere, stratosphere, mesosphere, and the thermosphere. Almost all of the Earth’s weather occurs in the troposphere. Almost all of the Earth’s weather occurs in the troposphere.

8. Temperature decreases with increasing altitude because the air becomes less dense. The temperature of the troposphere drops about 6.5 o C for every kilometer above the Earth’s surface. However, at an altitude of about 12 kilometers, the temperature seems to stop dropping. The zone of the troposphere where the temperature remains fairly constant is called the tropopause. The tropopause divides the troposphere from the next layer of the atmosphere. Temperature decreases with increasing altitude because the air becomes less dense. The temperature of the troposphere drops about 6.5 o C for every kilometer above the Earth’s surface. However, at an altitude of about 12 kilometers, the temperature seems to stop dropping. The zone of the troposphere where the temperature remains fairly constant is called the tropopause. The tropopause divides the troposphere from the next layer of the atmosphere.

9. Most of the ozone in the atmosphere is located in a layer of the stratosphere. Most of the ozone in the atmosphere is located in a layer of the stratosphere. The upper mesosphere is the coldest region of the atmosphere. The upper mesosphere is the coldest region of the atmosphere. The thermosphere is made up of the ionosphere and the exosphere. The thermosphere is made up of the ionosphere and the exosphere.

10. The Van Allen radiation belts are layers of high radiation that form as a result of the concentration of charged particles. These charged particles are from storms which occur on the sun. The Van Allen radiation belts are layers of high radiation that form as a result of the concentration of charged particles. These charged particles are from storms which occur on the sun. When there is a solar flare, the magnetosphere is bombarded by large quantities of electrically charged particles from the sun. These charged particles get trapped in the magnetosphere. Here they collide with other particles in the upper atmosphere. The collisions cause the atmospheric particles to give off light. The multicolored lights are called auroras. When there is a solar flare, the magnetosphere is bombarded by large quantities of electrically charged particles from the sun. These charged particles get trapped in the magnetosphere. Here they collide with other particles in the upper atmosphere. The collisions cause the atmospheric particles to give off light. The multicolored lights are called auroras.