Search results
Results from the WOW.Com Content Network
[1] [failed verification] 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). [citation needed]
Extreme of darkest storm clouds, sunset or sunrise 10 1: 1 decalux: 40 lux: Fully overcast, sunset or sunrise 10 2: 1 hectolux < 200 lux: Extreme of darkest storm clouds, midday 400 lux: Sunrise or sunset on a clear day (ambient illumination) 10 4: 10 kilolux: 10–25 kilolux: Typical overcast day, midday 20 kilolux: Shade illuminated by entire ...
Blue hour usually lasts about 20–96 minutes right after sunset and right before sunrise. Time of year, location, and air quality all have an influence on the exact time of blue hour. [ 7 ] For instance in Egypt (every 21st of June ), when sunset is at 7:59 PM : blue hour occurs from 7:59 PM to 9:35 PM.
For a certain period after sunset and before sunrise, indirect light from the Sun lightens the sky on Earth; this period is often referred to as twilight. Certain groups, such as Earthly astronomers, do not consider daytime to be truly ended until the Sun's disc is actually well below the Earth's horizon, because of this indirect illumination.
The reddish color of the Sun when it is observed through a thick atmosphere, as during a sunrise or sunset. This is because long-wavelength (red) light is scattered less than blue light. The red light reaches the observer's eye, whereas the blue light is scattered out of the line of sight.
On Earth, the terminator is a circle with a diameter that is approximately that of Earth. [1] The terminator passes through any point on Earth's surface twice a day, at sunrise and at sunset, apart from polar regions where this only occurs when the point is not experiencing midnight sun or polar night.
Dawn begins with the first sight of lightness in the morning, and continues until the Sun breaks the horizon. The morning twilight is divided in three phases, which are determined by the angular distance of the centre of the Sun (degrees below the horizon) in the morning.
In the case of alpenglow, which is similar to the Belt of Venus, [7] afterglow is used in general for the golden-red glowing light from the sunset and sunrise reflected in the sky, and in particularly for its last stage, when the purple light is reflected. [2] [1] The opposite of an afterglow is a foreglow, which occurs before sunrise ...