albedo


albedo
/al bee"doh/, n., pl. albedos.
1. Astron. the ratio of the light reflected by a planet or satellite to that received by it.
2. Meteorol. such a ratio for any part of the earth's surface or atmosphere.
3. the white, inner rind of a citrus fruit.
[1855-60; < LL albedo whiteness, equiv. to alb(us) white + -edo n. suffix; cf. TORPEDO]

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Fraction of light reflected by a body or surface, commonly used in astronomy to describe the reflective properties of planets, natural satellites, and asteroids.

"Normal" albedo (the relative brightness of a surface when illuminated and observed from directly above) is often used to determine the surface compositions of satellites and asteroids. The albedo, diameter, and distance of such objects together determine their brightness.

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      fraction of light that is reflected by a body or surface. It is commonly used in astronomy to describe the reflective properties of planets, satellites, and asteroids.

      Albedo is usually differentiated into two general types: normal albedo and bond albedo. The former, also called normal reflectance, is a measure of a surface's relative brightness when illuminated and observed vertically. The normal albedo of snow, for example, is nearly 1.0, whereas that of charcoal is about 0.04. Investigators frequently rely on observations of normal albedo to determine the surface compositions of satellites and asteroids. The albedo, diameter, and distance of such objects together determine their brightness. If the asteroids Ceres and Vesta, for example, could be observed at the same distance, Vesta would be the brighter of the two by roughly 10 percent. Though Vesta's diameter measures less than half that of Ceres, Vesta appears brighter because its albedo is about 0.35, whereas that of Ceres is only 0.09.

      Bond albedo, defined as the fraction of the total incident solar radiation reflected by a planet back to space, is a measure of the planet's energy balance. (It is so named for the American astronomer George P. Bond, who in 1861 published a comparison of the brightness of the Sun, the Moon, and Jupiter.) The value of bond albedo is dependent on the spectrum of the incident radiation because such albedo is defined over the entire range of wavelengths. Earth-orbiting satellites have been used to measure the Earth's bond albedo. The most recent values obtained are approximately 0.33. The Moon, which has a very tenuous atmosphere and no clouds, has an albedo of 0.12. By contrast, that of Venus, which is covered by dense clouds, is 0.76.

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Universalium. 2010.

Look at other dictionaries:

  • albédo — [ albedo ] n. m. • 1901; en angl. 1859; bas lat. albedo « blancheur » ♦ Phys., astron. Fraction du flux total de particules incidentes renvoyé par réflexion diffuse à la surface de séparation de deux milieux. Un corps noir possède un albédo nul.… …   Encyclopédie Universelle

  • Albedo — Albédo Type de surface Albédo (0 à 1) Surface de lac 0,02 à 0,04 Forêt de conifères 0,05 à 0,15 Surface de la mer 0,05 à 0,15 Sol sombre 0,05 à 0,15 Cultures 0,15 à 0,25 Sable léger et sec 0,25 à 0,45 Glace environ 0,60 …   Wikipédia en Français

  • albedo — ALBÉDO subst. Mărime care indică fracţiunea din energia luminoasă incidentă radiată în mod difuz de un corp. – Din fr. albédo. Trimis de ana zecheru, 12.11.2002. Sursa: DEX 98  albédo s. n., art. albédoul Trimis de siveco, 10.08.2004. Sursa:… …   Dicționar Român

  • Albedo 0.39 — es un Álbum conceptual de música electrónica compuesto por Vangelis. Características Fue grabado en 1976 en los estudios Nemo de Londres, y fue el segundo álbum producido por el mismo Vangelis. El nombre hace referencia al albedo promedio de la… …   Wikipedia Español

  • albedo — lúnula de la uña. Blancura Diccionario ilustrado de Términos Médicos.. Alvaro Galiano. 2010. albedo Blancura, particularmente como superficie de reflexión. Diccionario Mosby Medicina, Enfermería y Ciencias de la Salud, Ediciones Hanc …   Diccionario médico

  • albedo — (n.) ratio of light reflected from a surface, 1859, from L. albedo, lit. whiteness, from albus white (see ALB (Cf. alb)) …   Etymology dictionary

  • albedo — (Del lat. albēdo, blancura). m. Fís. Razón entre la energía luminosa que difunde por reflexión una superficie y la energía incidente …   Diccionario de la lengua española

  • Albedo — Al*be do, n. [L., fr. albus white.] Whiteness. Specifically: (Astron.) The ratio which the light reflected from an unpolished surface bears to the total light falling upon that surface. [1913 Webster] …   The Collaborative International Dictionary of English

  • Albēdo — (lat., »die Weiße«), nach Lambert das Verhältnis der von einem beleuchteten Körper nach allen Richtungen diffus ausgestrahlten Lichtmenge zu der auffallenden Lichtmenge. Nach Zöllner ist die A. des weißen Papiers 0,7, d.h. weißes Papier wirft 0,7 …   Meyers Großes Konversations-Lexikon

  • Albedo — Albedo, s. Absorption des Lichts, S. 3 …   Lexikon der gesamten Technik

  • Albedo — Albēdo (lat., »die Weiße«), in der Photometrie das Verhältnis der von einem rauhen, nicht spiegelnden Flächenstück zurückgeworfenen zu der von ihm empfangenen Lichtmenge. In der Astronomie wird der Ausdruck A. für die Helligkeit der Planeten… …   Kleines Konversations-Lexikon


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