The Ozone Layer

atmosphere · protection · science

Invisible protector. The ozone layer is a region of gas about 15 to 35 kilometers (9 to 22 miles) above Earth that sits in the stratosphere and absorbs most of the Sun's ultraviolet radiation, keeping us safe from its harmful effects.

What's ultraviolet?. Ultraviolet (UV) radiation from the Sun is invisible light energy that can damage skin and cause sunburns. The ozone layer blocks most of it before it reaches us on the ground.

Tiny but mighty. Ozone is a special form of oxygen made of three oxygen atoms bonded together (O3). The ozone layer only has about 8 to 15 parts per million of ozone, but that's enough to do an amazing job protecting Earth.

Location matters. The ozone layer isn't the same everywhere. It's thickest and thinnest at different times of year, and its thickness changes depending on where you are on Earth, like being stronger near the poles and weaker near the equator.

Part of the air above. While the ozone layer has high amounts of ozone compared to other parts of the atmosphere, the average ozone in Earth's whole atmosphere is still pretty low at just 0.3 parts per million.