Ozone, a molecule consisting of three oxygen atoms (O3), wasn't born at a specific point in time like a living organism. Instead, its formation is a continuous process driven by photochemical reactions, meaning reactions triggered by sunlight.
Over two billion years ago, early aquatic organisms called blue-green algae began producing molecular oxygen (O2) as a byproduct of photosynthesis. This oxygen, released into the atmosphere, interacted with ultraviolet (UV) radiation from the Sun. The UV energy broke down some of the O2 molecules, creating single oxygen atoms. These atoms then recombined with other O2 molecules, forming ozone (O3).
Therefore, the birth of ozone is an ongoing process that started with the emergence of oxygen in the atmosphere. While the exact timing of ozone formation is difficult to pinpoint, it likely began shortly after the release of significant amounts of oxygen by early photosynthetic organisms.
