Where is civil twilight from

Not everyone felt the need to give a precise degree to the beginning or end of civil twilight. Very frequently one may notice, after the setting of the sun, when one it standing on an eminence, a red arch defined upon the eastern sky around a darkish-blue space.

Under favorable circumstances, the line of separation is marked by a yellowish edging. This is the phenomenon that has been styled the anti-twilight.

Whatever it's called, the hazy times between night and day are great times to pull out other, more poetic terms to describe what you're seeing and feeling, taking in the bits of sunlight. Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free! Log in Sign Up. Photo: thekopmylife. More Words At Play.

Merriam-Webster's Words of the Week - Oct. Merriam-Webster's Words of the Week - Nov. In civil twilight , the sky is light all over though the sun is not visible. Following are some observations of those stages, with an eye toward how they look to pedestrians and cyclists.

Nautical twilight, morning : Half an hour in which it goes from dark to some lightening of the sky and pale or reddish at the eastern edge. Bicyclists on the street definitely would want the full complement of lights. Civil twilight, morning : Half an hour in which the sky lightens all over.

At the start of civil twilight, the sky is light blue and colors of objects are easier to detect. By the midpoint, you can read a newspaper outside under open sky. Technically, the end of civil twilight coincides with sunrise. In much of the Bay Area, though, the sun is not visible until about 10 minutes after official sunrise time, because of the hills to the east.

In much of the Bay Area, the sun disappears behind the western hills 10 minutes or more before official sunset time. Several countries use this definition of civil twilight to make laws related to aviation, hunting, and the usage of headlights and street lamps. Nautical twilight occurs when the center of the Sun is between 6 degrees and 12 degrees below the horizon. This twilight period is less bright than civil twilight and artificial light is generally required for outdoor activities.

Nautical dawn occurs when the Sun is 12 degrees below the horizon during the morning. Nautical dusk occurs when the Sun is 12 degrees below the horizon in the evening. The term, nautical twilight , dates back to the time when sailors used the stars to navigate the seas. During this time, most stars can be easily seen with naked eyes, and the horizon is usually also visible in clear weather conditions. In addition to being important to navigation on the seas, nautical twilight also has military implications.

For example, the military forces of the United States use nautical twilight, as reflected by the terms begin morning nautical twilight BMNT and end evening nautical twilight EENT , to plan tactical operations. Astronomical twilight occurs when the Sun is between 12 degrees and 18 degrees below the horizon.

Astronomical dawn is the time when the center of the Sun is at 18 degrees below the horizon. Astronomical dusk is the instant when the center of the Sun is at 18 degrees below the horizon. During astronomical twilight, most celestial objects can be observed in the sky.