Are twilight stars dating

28-Dec-2016 05:33

There are three established and widely accepted subcategories of twilight: civil twilight (nearest the horizon), nautical twilight, and astronomical twilight (farthest from the horizon).

In the United States' military, the initialisms BMCT (begin morning civil twilight, i.e.

civil dawn) and EECT (end evening civil twilight, i.e.

civil dusk) are used to refer to the start of morning civil twilight and the end of evening civil twilight, respectively.

It marks the beginning of evening astronomical twilight and the end of evening nautical twilight.

At nautical dawn and nautical dusk, the human eye finds it difficult, if not impossible, to discern traces of illumination near the sunset or sunrise point of the horizon ("first light” after nautical dawn but before civil dawn and "nightfall" after civil dusk but before nautical dusk).

Twilight is produced by sunlight scattering in the upper atmosphere, illuminating the lower atmosphere so that Earth's surface is neither completely lit nor completely dark.

The word twilight is also used to denote the periods of time when this illumination occurs.

The farther the Sun is below the horizon, the dimmer the twilight (other things such as atmospheric conditions being equal).

The collateral adjective for twilight is crepuscular which is sometimes applied to insects, fish, and mammals that are most active during that time.

, which is the position of the geometric center of the sun relative to the horizon.

Twilight is produced by sunlight scattering in the upper atmosphere, illuminating the lower atmosphere so that Earth's surface is neither completely lit nor completely dark.

The word twilight is also used to denote the periods of time when this illumination occurs.

The farther the Sun is below the horizon, the dimmer the twilight (other things such as atmospheric conditions being equal).

The collateral adjective for twilight is crepuscular which is sometimes applied to insects, fish, and mammals that are most active during that time.

, which is the position of the geometric center of the sun relative to the horizon.

It is preceded by morning astronomical twilight and followed by morning nautical twilight.