The natural phenomenon that occurs during a total eclipse of the sun is called a "solar eclipse." In this event, the moon passes between the Earth and the sun, obscuring the sun's light either partially or completely, depending on the viewer's location. During a total solar eclipse, the day turns briefly to darkness, allowing observers to see the sun's corona, or outer atmosphere, which is usually hidden by the sun's brightness. This rare and awe-inspiring event captivates millions of viewers, as it offers a unique opportunity to witness the intricate dynamics of our solar system and fosters both scientific interest and public fascination.