Earth's Atmosphere: A jacket for the planet (for younger readers)
Earth is a great planet to live on. It has a wonderful atmosphere around it. This jacket of gases does a lot for us. It keeps us warm, it gives us air to breathe, it protects us from the sun, and it's where the weather happens.
The layers in the Atmosphere. The ionosphere takes up part of the exosphere, thermosphere, and parts of the mesosphere.
Earth's Atmosphere has six different layers: the troposphere, stratosphere, mesosphere, thermosphere, ionosphere, and exosphere. They go from the ground all the way to outer space.
The Weather Layer
The troposphere is the closest layer to Earth. It's where almost all weather happens. "Tropos" means change, which makes sense because the troposphere is always changing and mixing up the gases inside it. This layer has the air we breathe and the clouds in the sky.
The Ozone Layer
The stratosphere is above the troposphere. "Strat" means layer. This layer of our atmosphere has its own set of layers. There are no storms or winds here to mix up the air. Cold, heavy air is at the bottom, while warm, light air is at the top. That's the opposite of how things work in the troposphere.
The stratosphere starts just above the troposphere and goes on for 31 miles from the Earth's surface. The stratosphere is where you'll find the ozone layer. The ozone layer helps protect us from the sun. Without the ozone, the sun would cause too much heat and energy on Earth.
The Shooting Stars Layer
The mesosphere is between the thermosphere and the stratosphere. "Meso" means middle. This is the highest layer of the atmosphere in which the gases are all mixed up instead of being separated in layers.
The mesosphere starts just above the stratosphere. There is not enough air up in the mesosphere for people to breathe.
It is also the layer where meteors burn up. These large rocks heat up when they hit the air in the mesosphere. That's why they look like shooting stars in the sky.
An image of the Perseid Meteor Shower. Photo: National Park Service. [click to enlarge]
The Satellites Layer
The thermosphere is between the exosphere and the mesosphere. "Thermo" means heat. Back on the ground, the hottest place can only reach 130 degrees Fahrenheit, which is already very hot for humans. But in the thermosphere, the temperature can reach up to 4,500 degrees Fahrenheit.
If you were in the thermosphere, though, you would still be very cold. The air is hot, but there is not a lot of it. So, a person's body would not get touched by much of the heat.
The thermosphere is where some satellites move around Earth. These are machines that are sent into space to study the stars and planets.
The Polar Bands Of Light Layer
The ionosphere takes up part of the mesosphere, thermosphere and exosphere. It grows and shrinks based on the energy it takes in from the sun.
The Aurora Borealis viewed from the International Space Station. Photo: NASA/JSC. [click to enlarge]
The ionosphere is where auroras happen. Auroras are the bright, beautiful bands of light that you sometimes see near Earth's poles. They're caused when energy from the sun hits parts of our atmosphere.
The 6,200-Miles-High Layer
The exosphere is the highest layer of our atmosphere. "Exo" means outside. This layer separates the rest of the atmosphere from outer space, and it goes from the top of the thermosphere up to about 6,200 miles high. It is almost as wide as Earth itself. Up there, there is no air to breathe and it's very cold.