The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation).
1. The sky is falling. (Or a least the clouds.) A cloud consists of droplets of water suspended in air. As you might expect, adding the droplets of water increases the density. A cloud at the same temperature as surrounding air will be more dense than the surrounding air. So why don’t clouds fall? In fact, in some sense, they do! The big, puffy cumulus clouds that you see form atop columns of rising air. The air is moving upward. So the bottom of the cloud is—relative to the air—moving downward. The clouds are falling! Whenever you see cumulus clouds in the sky, that tells you that the air is moving vertically. Clouds mean rising air (and thus falling clouds!) and clear sky means falling air.
Most people know that satellites in orbit do useful things such as collect images of the Earth's surface. At the National Air and Space Museum I use satellite images in my job to understand changes in
Earth is the only planet in the solar system with an atmosphere that can sustain life.
Earth's atmosphere has a series of layers, each with its own specific traits. Moving upward from ground level, these layers are named the troposphere, stratosphere, mesosphere, thermosphere and exosphere.