Layers of the Atmosphere

Layers of the Atmosphere

Middle School

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Learning Objectives

• List the five layers of Earth's atmosphere in order from the ground up.

• Describe the key characteristics of each atmospheric layer, like temperature and unique phenomena.

• Explain the atmosphere's composition and the significance of the ozone layer.

• Identify the layers where weather, meteors, and satellites are found.

Key Vocabulary

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Atmosphere

The envelope of gases that surrounds the Earth, held in place by the pull of gravity.

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Troposphere

The lowest atmospheric layer where we live and all of Earth's weather takes place.

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Stratosphere

This layer contains the ozone layer, which protects us from the sun's harmful ultraviolet radiation.

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Mesosphere

This is the middle layer of the atmosphere where meteors burn up upon entering from space.

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Thermosphere

The second-highest layer, known for its high temperatures and the location of the Aurora Borealis.

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Exosphere

This is the outermost layer of our atmosphere, where it gradually thins and merges into space.

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What is the Atmosphere?

• Earth has a protective layer of gases which is called the atmosphere.

• ​This layer gives us air to breathe and regulates the Earth's temperature.

• It is mainly composed of 78% nitrogen and 21% oxygen.

• The other 1% are gases like argon and carbon dioxide.

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Multiple Choice

What are the two most abundant gases in the Earth's atmosphere?

• Nitrogen and Oxygen

• Oxygen and Carbon Dioxide

• Nitrogen and Argon

• Helium and Hydrogen

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The Troposphere

• This is the lowest layer of the atmosphere, where we live.

• It extends from the surface up to about 16 km (10 miles).

• It contains 99% of water vapor, creating all weather and clouds.

• As you go higher, the temperature and air pressure become lower.

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Multiple Choice

What happens to the temperature as you increase in altitude within the troposphere?

• It decreases

• It increases

• It stays the same

• It fluctuates randomly

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The Stratosphere

• The stratosphere is located above the troposphere, from about 16 to 50 km.

• ​This layer contains the vital ozone layer, which protects life on Earth.

• It absorbs most of the Sun's harmful ultraviolet (UV) radiation.

• Temperature increases with altitude, and airplanes fly here to avoid weather turbulence.

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Multiple Choice

What is the primary function of the ozone layer located in the stratosphere?

• To absorb the Sun's ultraviolet radiation

• To create weather patterns

• To burn up meteors

• To reflect radio waves

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The Mesosphere: The Middle Layer

• The mesosphere is the middle layer, extending to about 90 km high.

• It is the coldest layer with very thin air, lacking breathable oxygen.

• It protects Earth by burning up most meteoroids entering this layer.

• These burning meteoroids are visible from Earth as “shooting stars.”

Multiple Choice

What major protective event occurs in the mesosphere?

• Meteors burn up

• Harmful UV rays are absorbed

• The Aurora Borealis appears

• Weather patterns are formed

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The Thermosphere and Exosphere

Thermosphere

• This layer is located from about 90 km to 600 km and is the hottest layer.

• Temperatures can reach up to 2,000°F, and its name comes from 'thermos,' meaning heat.

• The thermosphere is very hot, but its sparse gas particles transfer little heat to objects like satellites.

• The Aurora Borealis occurs here, and space shuttles fly within this atmospheric layer.

Exosphere

• The exosphere is the outermost layer of Earth's atmosphere, starting around 500–600 km and gradually merging with outer space.

  It consists mainly of hydrogen and helium, with extremely low particle density.

  Satellites orbit near the lower exosphere, while gravity is very weak at this height.

Multiple Choice

Which layer is known for being the hottest and is where the Aurora Borealis is found?

• Thermosphere

• Mesosphere

• Stratosphere

• Exosphere

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Common Misconceptions about the Atmosphere

Misconception	Correction
The atmosphere is the same everywhere.	It has five distinct layers, each with unique properties.
Temperature always gets colder as you go higher.	Temperature changes direction in different layers.
The ozone layer is a hole in the sky.	It is a thinning layer that protects us from UV rays.
Space begins right after the clouds.	The final layer, the exosphere, is hundreds of kilometers up.

Multiple Choice

An airplane is flying at 35,000 feet to avoid a thunderstorm. Which layer is it most likely in, and why?

• The stratosphere, because it is above the weather in the troposphere.

• The troposphere, because that is where all airplanes fly.

• The mesosphere, because it is the calmest layer.

• The thermosphere, because it is warmer for the plane.

Multiple Choice

Why is the thermosphere, despite having extremely high temperatures, not able to transfer much heat to objects within it, like a satellite?

• Because the gas particles are extremely far apart and cannot transfer energy effectively.

• Because satellites are designed to be cold and reflect all heat.

• Because the thermosphere is actually the coldest layer, not the hottest.

• Because the heat is absorbed by the Aurora Borealis.

Multiple Choice

If a meteoroid successfully passed through the mesosphere without burning up completely and was on track to hit Earth, what layers would it still have to pass through in order?

• Stratosphere, then Troposphere

• Thermosphere, then Stratosphere

• Troposphere, then Stratosphere

• Exosphere, then Thermosphere

Multiple Choice

What would be the most likely immediate consequence for life on Earth if the stratosphere's ozone layer completely disappeared?

• A dangerous increase in exposure to the Sun's UV radiation.

• A significant change in weather patterns and cloud formation.

• A decrease in the number of meteors hitting the Earth's surface.

• A change in the Earth's orbit around the sun.

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Summary

• The atmosphere is a multi-layered gas envelope, primarily nitrogen and oxygen.

• The troposphere is where we live and where all weather occurs.

• The stratosphere has the ozone layer; the mesosphere burns up most meteors.

• The thermosphere contains auroras, and satellites orbit in the exosphere.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

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