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Daylight is the combination of all direct and indirect sunlight during the daytime. This includes direct sunlight, diffuse sky radiation, and (often) both of these reflected by Earth and terrestrial objects, like landforms and buildings. Sunlight scattered or reflected by astronomical objects is generally not considered
If the extraterrestrial solar radiation is 1,367 watts per square meter (the value when the Earth–Sun distance is 1 astronomical unit), then the direct sunlight at Earth's surface when the Sun is at the zenith is about 1,050 W/m 2, but the total amount (direct and indirect from the atmosphere) hitting the ground is around 1,120 W/m 2. [6]
Because rainbows are seen on the opposite side of the sky from the Sun, rainbows are more visible the closer the Sun is to the horizon. For example, if the Sun is overhead, any possible rainbow appears near an observer's feet, making it hard to see, and involves very few raindrops between the observer's eyes and the ground, making any rainbow ...
Earthlight is the diffuse reflection of sunlight reflected from Earth's surface and clouds. Earthshine (an example of planetshine ), also known as the Moon's ashen glow , is the dim illumination of the otherwise unilluminated portion of the Moon by this indirect sunlight.
Approximately half of Earth is illuminated at any time by the Sun.The area subjected to direct illumination is almost exactly half the planet; but because of atmospheric and other effects that extend the reach of indirect illumination, the area of the planet covered by either direct or indirect illumination amounts to slightly more than half the surface.
Daylighting is the practice of placing windows, skylights, other openings, and reflective surfaces so that direct or indirect sunlight can provide effective internal lighting. Particular attention is given to daylighting while designing a building when the aim is to maximize visual comfort or to reduce energy use.
Ordon reiterates that direct sun exposure — a.k.a. being outside in the sun — can help the body produce enough vitamin D, but for the vast majority of people in the U.S., this is only possible ...
For example, NASA's Navigation and Ancillary Information Facility defines that a body in the umbra is also within the penumbra. [2] Scale diagram of Earth's shadow, showing how the umbral cone extends beyond the orbit of the Moon (The Moon is indicated by the yellow dot.) Earth's umbra, as seen during a partial lunar eclipse