When the Sun again reaches 18° below the horizon, nighttime becomes morning twilight.
When the Sun reaches 18° below the horizon, the twilight's brightness is nearly zero, and evening twilight becomes nighttime. The lower the Sun is beneath the horizon, the dimmer the twilight (other factors such as atmospheric conditions being equal). The word twilight can also refer to the periods of time when this illumination occurs. Twilight is light produced by sunlight scattering in the upper atmosphere, when the Sun is below the horizon, which illuminates the lower atmosphere and the Earth's surface. Evening twilight: civil, nautical, and astronomical stages at dusk.
0 kommentar(er)
