The Sun creates the Earth's ozone layer by transforming oxygen molecules into a protective shield.

The ozone layer is located in the stratosphere, roughly 15 to 35 kilometers above the Earth's surface. This process, known as the Chapman Cycle, was first documented by British physicist Sydney Chapman in 1930. It begins when high-energy UV-C radiation strikes a diatomic oxygen molecule (O2) and splits it into two individual oxygen atoms.These highly reactive free atoms quickly collide with other O2 molecules to form triatomic ozone (O3). While ozone is constantly being created, it is also being destroyed as it absorbs UV-B and UV-C radiation, which converts it back into O2 and a free oxygen atom. This delicate balance is what allows the stratosphere to filter out approximately 97% to 99% of the Sun's medium-frequency ultraviolet light.Without this natural filtration system, life on land would be nearly impossible due to intense radiation damage to DNA and plant tissues. Research from NASA and the National Oceanic and Atmospheric Administration (NOAA) confirms that ozone density varies by season and latitude. Despite its importance, the entire ozone layer is surprisingly thin. If compressed to sea-level pressure, it would be only about 3 millimeters thick.