Twilight is the period before sunrise and after sunset when the Sun is below the horizon but its light is still scattered through Earth’s atmosphere. This scattering bends sunlight around the planet, illuminating the sky even when the Sun itself is no longer visible. Twilight is divided into three main types, civil, nautical, and astronomical, based on how far below the horizon the Sun is, and each represents a distinct stage in the transition from day to night.
Civil twilight occurs when the Sun is between 0° and 6° below the horizon. During this phase, there is still enough natural light for most outdoor activities without artificial lighting. The sky often displays vivid reds, oranges, and pinks near the horizon, including the Belt of Venus, a soft pink band visible opposite the Sun caused by Earth’s shadow rising into the atmosphere, while the brightest stars and planets begin to appear. Civil twilight is commonly associated with the everyday concepts of dawn and dusk and is widely used in photography, aviation, and urban lighting schedules.