Moonlight
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Moonlight consists of mostly sunlight (with little earthlight) reflected from the parts of the Moon's surface where the Sun's light strikes.<ref name=Toomer>Template:Cite journal</ref>
HistoryEdit
The ancient Greek philosopher Anaxagoras was aware that "the sun provides the moon with its brightness".<ref>Fragment in Plutarch De facie in orbe lunae, 929b, as quoted in "The Riverside Dictionary of Biography" (2005), p. 23</ref>
Zhang Heng's treatise "The Spiritual Constitution of the Universe" concludes that the light of the moon comes from the Sun. He writes that the Sun and Moon are "like fire and water" where the Sun "gives out light" and the Moon "reflects it". <ref>Dinwiddie, R., Hughes, D. W., Jackson, T., Johnson, P., Mitton, J. (2017). The Astronomy Book. DK Big Ideas. p.23</ref>
IlluminationEdit
The intensity of moonlight varies greatly depending on the lunar phase, but even the full moon typically provides only about 0.05–0.1 lux illumination.<ref name=supermoon>Template:Cite journal</ref> When a full Moon around perigee (a "supermoon") is viewed around upper culmination from the tropics, the illuminance can reach up to 0.32 lux.<ref name=supermoon/> From Earth, the apparent magnitude of the full Moon is only about Template:Fract that of the Sun.Template:Citation needed
The color of moonlight, particularly around full moon, appears bluish to the human eye compared to other, brighter light sources due to the Purkinje effect. The blue or silver appearance of the light is an illusion.
The Moon's Bond albedo averages 0.136,<ref name="Saari">Template:Cite journal</ref> meaning only 13.6% of incident sunlight is reflected from the lunar surface. Moonlight takes approximately 1.26 seconds to reach Earth's surface. Scattered in Earth's atmosphere, moonlight generally increases the brightness of the night sky, reducing contrast between dimmer stars and the background. For this reason, many astronomers usually avoid observing sessions around a full moon.
GalleryEdit
- ISS-44 Moon - Goodnight Earth.jpg
Moonlight onto Earth's cloud cover from space
- Sunrise over the VLT.jpg
Moonlight shines on the Very Large Telescope.
- Tonsvatnet, tåke og måne.JPG
Moonlight illuminates a lake and surroundings.
- Giftedtypist - red moon (by).jpg
During a lunar eclipse, the Moon is colored red by indirect sunlight, which Earth's atmosphere has scattered and refracted.
- Earthshine Moon.jpg
Earthlight (indirect sunlight reflected from Earth) illuminates the dim side of the Moon, while direct sunlight the bright side.
FolkloreEdit
In folklore, moonlight sometimes has a harmful influence. For example, sleeping in the light of a full Moon on certain nights was said to transform a person into a werewolf. The light of the Moon was thought to worsen the symptoms of lunatics, and to sleep in moonlight could make one blind, or mad.<ref>A Dictionary of English Folklore, Oxford University Press, 2000</ref> Nyctalopia (night blindness caused by a lack of vitamin A) was thought to be caused by sleeping in moonlight in the tropics.
"Moon blindness" is a name for equine recurrent uveitis. Moonlight is no longer thought of as the cause.
In the 16th century, moonmilk, a soft white limestone precipitate found in caves, was thought to be caused by the rays of the Moon.<ref name=Gessner>Template:Cite book</ref>
Selenoplexia was a supposed medical condition caused by the rays of the moon.<ref name=Lippincott>Lippincott's Medical dictionary (Lippincott, 1906), p. 920.</ref>
ArtEdit
- Joseph Vernet - Night - Seaport by Moonlight - WGA24731.jpg
Seaport by Moonlight (1771) by Claude Joseph Vernet
- Joseph Wright of Derby - Dovedale by Moonlight - Google Art Project.jpg
Dovedale by Moonlight (1784) by Joseph Wright of Derby
- Philippe-Jacques de Loutherbourg - A Philosopher in a Moonlit Churchyard.jpg
- Ed. Manet. Clair de lune sur le port de Boulogne.jpg
- Van Gogh - Starry Night - Google Art Project.jpg
The Starry Night (1889) by Vincent van Gogh
- Stanisław Witkiewicz - Wiatr halny 1895.jpg
Halny (1895) by Stanisław Witkiewicz
In 2008 Katie Paterson produced an artwork titled Light bulb to Simulate Moonlight.<ref name=guggenheimPaterson /> It consists of 289 lightbulbs coated to produce a similar spectrum to the light of the full Moon.<ref name=guggenheimPaterson>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
See alsoEdit
- Airglow
- Daylight
- Diffuse reflection
- Earthlight (astronomy)
- Lunar effect
- Scotobiology
- Starlight
- Night in paintings (Western art)
- Night in paintings (Eastern art)