Holma Boat Club by the light of the moon

Moonlight consists of mostly

sunlight Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when ...

(with little

earthlight ''Earthlight'' is a science fiction novel by British writer Arthur C. Clarke, published in 1955. It is an expansion to novel length of a novella of the same name that he had published four years earlier. Overview ''Earthlight'' is a scie ...

) reflected from the parts of the Moon's surface where the Sun's light strikes.

Illumination

The intensity of moonlight varies greatly depending on the

lunar phase Concerning the lunar month of ~29.53 days as viewed from Earth, the lunar phase or Moon phase is the shape of the Moon's directly sunlit portion, which can be expressed quantitatively using areas or angles, or described qualitatively using the t ...

, but even the

full Moon The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective. This occurs when Earth is located between the Sun and the Moon (when the ecliptic longitudes of the Sun and Moon differ by 180°). This mea ...

typically provides only about 0.05–0.1

lux The lux (symbol: lx) is the unit of illuminance, or luminous flux per unit area, in the International System of Units (SI). It is equal to one lumen per square metre. In photometry, this is used as a measure of the intensity, as perceived by ...

illumination. When a full Moon around

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any el ...

(a " supermoon") is viewed around upper

culmination In observational astronomy, culmination is the passage of a celestial object (such as the Sun, the Moon, a planet, a star, constellation or a deep-sky object) across the observer's local meridian. These events were also known as meridian tran ...

from the

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also refer ...

, the illuminance can reach up to 0.32 lux. From Earth, the

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

of the full Moon is only about that of the Sun. The color of moonlight, particularly around full moon, appears bluish to the

human eye The human eye is a sensory organ, part of the sensory nervous system, that reacts to visible light and allows humans to use visual information for various purposes including seeing things, keeping balance, and maintaining circadian rhythm. ...

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 is 0.12, meaning only 12% of incident sunlight is reflected from the lunar surface. Moonlight takes approximately 1.26 seconds to reach Earth's surface.

Scattered Scattered may refer to: Music * ''Scattered'' (album), a 2010 album by The Handsome Family * "Scattered" (The Kinks song), 1993 * "Scattered", a song by Ace Young * "Scattered", a song by Lauren Jauregui * "Scattered", a song by Green Day from ' ...

Earth's atmosphere The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing fo ...

, moonlight generally increases the

brightness Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. The perception is not linear to luminance, ...

of the

night sky The night sky is the nighttime appearance of celestial objects like stars, planets, and the Moon, which are visible in a clear sky between sunset and sunrise, when the Sun is below the horizon. Natural light sources in a night sky in ...

, reducing contrast between dimmer stars and the background. For this reason, many

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

s usually avoid observing sessions around full moon.

Gallery

File:ISS-44 Moon - Goodnight Earth.jpg, Moonlight onto Earth's cloud cover from space File:Sunrise over the VLT.jpg, Moonlight shines on the Very Large Telescope. File:Tonsvatnet, tåke og måne.JPG, Moonlight illuminates a lake and surroundings. File:Giftedtypist - red moon (by).jpg, During a

lunar eclipse A lunar eclipse occurs when the Moon moves into the Earth's shadow. Such alignment occurs during an eclipse season, approximately every six months, during the full moon phase, when the Moon's orbital plane is closest to the plane of the Ear ...

, the Moon is colored red by indirect

, which

has

scattered Scattered may refer to: Music * ''Scattered'' (album), a 2010 album by The Handsome Family * "Scattered" (The Kinks song), 1993 * "Scattered", a song by Ace Young * "Scattered", a song by Lauren Jauregui * "Scattered", a song by Green Day from ' ...

and refracted. File:Earthshine Moon.jpg,

Earthlight ''Earthlight'' is a science fiction novel by British writer Arthur C. Clarke, published in 1955. It is an expansion to novel length of a novella of the same name that he had published four years earlier. Overview ''Earthlight'' is a scie ...

(indirect sunlight reflected from Earth) illuminates the dim side of the Moon, while direct sunlight the bright side. File:High ISO with long exposure.jpg, With manual exposure settings, photographs taken in moonlight do not appear much different from those taken in daylight.

Folklore

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 In folklore, a werewolf (), or occasionally lycanthrope (; ; uk, Вовкулака, Vovkulaka), is an individual that can shapeshift into a wolf (or, especially in modern film, a therianthropic hybrid wolf-like creature), either purposely ...

. The light of the Moon was thought to worsen the symptoms of lunatics, and to sleep in moonlight could make one blind, or mad.''A Dictionary of English Folklore'', Oxford University Press, 2000

Nyctalopia Nyctalopia (; ), also called night-blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition ( ...

(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.

Moonlight in art

File:Joseph Vernet - Night - Seaport by Moonlight - WGA24731.jpg, ''Seaport by Moonlight'' (1771) by

Claude Joseph Vernet Claude-Joseph Vernet (14 August 17143 December 1789) was a French painter. His son, Antoine Charles Horace Vernet, was also a painter. Life and work Vernet was born in Avignon. When only fourteen years of age he aided his father, Antoine Verne ...

Image:Joseph Wright of Derby - Dovedale by Moonlight - Google Art Project.jpg, ''

Dovedale by Moonlight Dovedale is a valley in the Peak District of England. The land is owned by the National Trust and attracts a million visitors annually. The valley was cut by the River Dove and runs for just over between Milldale in the north and a wooded ...

'' (1784) by Joseph Wright of Derby File:Philippe-Jacques de Loutherbourg - A Philosopher in a Moonlit Churchyard.jpg, ''A Philosopher in a Moonlit

Churchyard In Christian countries a churchyard is a patch of land adjoining or surrounding a church, which is usually owned by the relevant church or local parish itself. In the Scots language and in both Scottish English and Ulster-Scots, this can also ...

'' (1790) by Philip James de Loutherbourg File:Ed. Manet. Clair de lune sur le port de Boulogne.jpg, '' The Port of Boulogne by Moonlight'' (1869) by

Édouard Manet Édouard Manet (, ; ; 23 January 1832 – 30 April 1883) was a French modernist painter. He was one of the first 19th-century artists to paint modern life, as well as a pivotal figure in the transition from Realism to Impressionism. Bor ...

File:Van Gogh - Starry Night - Google Art Project.jpg, '' The Starry Night'' (1889) by

Vincent van Gogh Vincent Willem van Gogh (; 30 March 185329 July 1890) was a Dutch Post-Impressionist painter who posthumously became one of the most famous and influential figures in Western art history. In a decade, he created about 2,100 artworks, inc ...

File:Stanisław_Witkiewicz_-_Wiatr_halny_1895.jpg, ''Halny'' (1895) by

Stanisław Witkiewicz Stanisław Witkiewicz ( lt, Stanislovas Vitkevičius) (8 May 1851 – 5 September 1915) was a Polish painter, art theoretician, and amateur architect, known for his creation of " Zakopane Style". Life Witkiewicz was born in Poszawsze in ...

Contemporary art

In 2008

Katie Paterson Katie Paterson (born 1981) is a Fife-based visual artist from Glasgow, Scotland, having previously lived and worked in Berlin whose artworks concern translation, distance, and scale. Paterson holds a BA from Edinburgh College of Art (2004) and ...

produced an artwork titled ''Light bulb to Simulate Moonlight''. It consists of 289 lightbulbs coated to produce a similar spectrum to the light of the full Moon.

References

External links

Phases of the Moon
at USNO
Strange Moonlight
a
Science@NASA

a

{{Parts of a day Lunar observation Light Light sources

Light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 t ...