The two main layers of the Earth's atmosphere are the troposphere and the stratosphere. The troposphere is the lowest layer, extending from the Earth's surface up to about 8 to 15 kilometers (5 to 9 miles) depending on the location. This layer contains most of the Earth's weather phenomena and is where clouds and storms form. Above the troposphere lies the stratosphere, which extends to about 50 kilometers (31 miles) above the surface. The stratosphere contains the ozone layer, which absorbs and scatters ultraviolet solar radiation, playing an essential role in protecting life on Earth.