What is the significance of twilight for Celestial Navigation?

The significance of twilight for celestial navigation lies primarily in its ability to allow the visibility of celestial bodies while the sun has set and is not directly visible. During twilight, especially during civil twilight which occurs shortly after sunset or before sunrise, the sky is still illuminated enough for navigators to observe stars and planets. This is particularly beneficial for celestial navigation, as navigators rely on these celestial bodies to determine their position and to take accurate sightings for navigation.

The timing of twilight means that navigators can identify prominent stars and constellations, and use them in conjunction with navigational tools such as sextants to establish their latitude and longitude. The visibility of celestial bodies during this time gives navigators a crucial window to obtain the necessary angular measurements to calculate their position before total darkness sets in.