How many layers are in the Earth's atmosphere?

The Earth's atmosphere is commonly divided into five distinct layers based on temperature variations and other characteristics. These layers are, from the Earth's surface upward: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.

The troposphere is the lowest layer where weather occurs and extends up to about 8 to 15 kilometers above the surface. Above that is the stratosphere, which contains the ozone layer and is where temperatures start to increase with altitude. The mesosphere follows, where temperatures decrease again with height. The thermosphere is characterized by a significant increase in temperature and includes the ionosphere, an area filled with charged particles. Finally, the exosphere is the outermost layer where the atmosphere gradually transitions into outer space.

This five-layer model is widely recognized in the scientific community, which makes it the correct choice in this context. Understanding these layers is crucial for comprehension of atmospheric science, including phenomena like climate and weather patterns.