Not all crepuscular creatures are active at both dawn and dusk some, like morning glory, are mainly active in the morning (matutinal) and others in the evening (vespertine), like evening primrose. Crepuscular is used to describe the many plants and animals that are active at dusk and dawn, including fireflies (which are actually beetles, not flies), moths, domestic cats, and rabbits. In fact, it comes from the Latin word for twilight, crepusculum. Ĭrepuscular is actually a very easy word to explain: it’s just an adjective for twilight. In this series, I’d like to take another approach by highlighting scientific words which have escaped the confines of jargon to reach a broader appeal because of their sound or their evocative power as metaphors. Most of the posts on this blog focus on breaching this barrier to the public’s understanding and appreciation of science. Topics: Astronomy, Sun, Atmospheric Phenomena Civil Twilight TodayĬivil Twilight from 06:48-07:20 in the morning.Ĭivil Twilight from 17:01-17:33 in the evening.Like many other fields, science has its own style of communication full of specific jargon and guided by unwritten rules. The iftar is an evening meal that occurs at dusk, when fasters are allowed to eat again. It is one of the five obligatory daily prayers, which together constitute one of the Five Pillars of Islam.ĭuring the Islamic month of Ramadan, Muslims are required to fast from dawn to the break of night. While it is common for Christians and adherents of other faiths to offer a prayer in the evening, Islam specifically defines dusk as the proper moment for the Maghrib evening prayer. In some contexts, dusk is also used to denote the setting of the Sun. Other colloquial synonyms include nightfall, sundown, and eventide. In everyday language, the term dusk is commonly used as another word for evening twilight-the period from sunset until nighttime. However, even the small portion of sunlight that is still scattered across the sky before the moment of astronomical dusk may hinder astronomers from observing some of the fainter stars and galaxies. The Sun is now 18 degrees below the horizon and the last shimmer of daylight has left the sky.Įven before astronomical dusk, during the period of astronomical twilight, the sky may look completely dark. This moment is the official beginning of night time. Most stars and constellations are now visible to the naked eye.įind the planets in the night sky Astronomical Dusk In clear weather conditions, it is now becoming difficult to distinguish the sky from land or water, making it impossible for sailors to use the horizon as a reference point when navigating by the stars. Nautical DuskĪt nautical dusk, the Sun is 12 degrees below the horizon. The 3 stages of dusk and evening twilight. The brightest stars and planets, like Venus and Jupiter, are now visible to the naked eye and more celestial bodies begin to appear in the sky. This is a good time for photographers to capture the sky and the soft glow of the sunlight.īeyond this point, artificial light is generally needed to carry out most outdoor activities. At this moment, the Earth's atmosphere still reflects a large portion of sunlight, coloring a clear sky in different shades of orange and red. It marks the end of civil twilight, which begins at sunset. Precise dusk and sunset times for your city Civil DuskĬivil dusk is when the geometric center of the Sun's disk goes 6 degrees below the horizon.
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