Sunset

Science / Weather / Sunset: The daily disappearance of the sun below the western horizon as a result of the earth's rotation. In the United States, it is considered as that instant when the upper edge of the sun just disappears below the sea level horizon. In Great Britain, the center of the sun's disk is used instead. Time of sunset is calculated for mean sea level.
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Civil Twilight

Science / Weather / Civil Twilight: The time between the moment of sunset, when the sun's apparent upper edge is just at the horizon, until the center of the sun is 6?° directly below the horizon. MORE

Scattering

Science / Weather / Scattering: The process by which small particles suspended in the air diffuse a portion of the incident radiation in all directions. This is a primary reason for colors, such as blue skies, rainbows, and orange s MORE

Twilight

Science / Weather / Twilight: Often called dusk, it is the evening period of waning light from the time of sunset to dark. The time of increasing light in the morning is called dawn. Twilight ends in the evening or begins in the m MORE