What is a naval twilight?

Nautical Twilight is the period in the morning and evening when the sun is between six and 12 degrees below the horizon. There is some visible light, but it is not enough to perform detailed activities without using artificial light and the horizon tends to be somewhat indistinct during this period. People refer to this time of day as "naval twilight" to refer to the fact that the sailors often accepted navigation observations during this time because visibility was ideal. Civil twilight occurs when the sun is less than six degrees below the horizon, which allows people to see things clearly, even if the sun is obviously on the way up or down. Another comes naval twilight, followed by an astronomical twilight between 12 and 18 degrees, and when the sun is more than 18 degrees bend is a horizon, it is considered a night. During this period, there are conventions and other obstacles to visibility, although clouding and fog may disrupt the perception of first light. People usually need headlights to drive and artificial light to work outdoorsduring the naval twilight.

At night, the naval twilight is sometimes called "twilight" and refers to the fact that the sky begins to darken rapidly, and soon it will be so dark that artificial light will be a necessity. Visibility can be difficult during this time because people may think it is lighter than it really is, and therefore the use of headlights and other AIDS can be visible, which can lead to aciproma.

The length of time spent in the twilight varies, depending on where it is in the world and how much is annual. Twilight tends to be the longest in the poles and the shortest around the equator; For example, in Alaska, Twilight can take several hours at some times of the year, while in parts of Africa, the light level moves from all -day light into the night in 20 minutes. Specific information on the times and length of the twilight is usually given in Sunrise-Sunset graphs issued by organizations that provide informatione o the weather.