The ozone layer is found in the Earth’s stratosphere, which is located between about 12 kilometers (km) and 50 kilometers above the Earth’s surface. This layer contains a high concentration of ozone (O₃) molecules, which help protect life on Earth by absorbing most of the sun’s harmful ultraviolet (UV) radiation. Without this protective layer, more UV rays would reach the surface, causing skin cancer, cataracts, and damage to plants and animals. The ozone layer is not found close to the Earth’s surface or very high up in the atmosphere but is mainly concentrated in this middle layer of the atmosphere. Scientists closely monitor the ozone layer because it is vital for the health of all living things on the planet.