Difference between revisions of "Lunar Albedo"

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(generic albedo info - needs to be made lunar specific)
 
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See the section on [[Albedo]] for the basic definition. For the Moon, the average albedo for the solar spectrum across the lunar surface is 0.12 (i.e. only 12% of incident sunlight is reflected back, and the remaining 88% is absorbed). From the Apollo missions it's known that a substantial portion of this reflected light is sent directly back at the Sun, so we never see it from Earth. At the angles we can see the Moon appears even darker, with an effective visual albedo of 8% or less.
{{Initial Proof Needed}}
 
'''Albedo'''
 
 
<BR/>The ratio of the amount of  
 
  
[[Electromagnetic Radiation|electromagnetic radiation]] reflected
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Individual features on the Moon have visual albedos that range from under 10% (the dark mare regions) to as high as 25-30% for bright ejecta and highland regions.
by a body to the amount incident upon it, often expressed as a percentage,
 
as,  '' the albedo of the earth is 34% '' . Compare
 
[[Bond Albedo|Bond albedo]].<BR>
 
<BR/> '' The concept defined above is identical with
 
[[Reflectance|reflectance]].
 
However, albedo is more commonly used in astronomy and meteorology
 
and reflectance in physics.
 
<BR>Albedo is sometimes used to mean the
 
flux of the reflected radiation as, the earth albedo is 0.64 calorie
 
per square centimeter. This usage should be discouraged. <BR>
 
  
The albedo is to be distinguished from the
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==References==
[[Spectral|spectral]] reflectance which
 
refers to one specific wavelength (monochromatic radiation).
 
<BR>Usage
 
varies somewhat with regard to the exact wavelength interval implied
 
in albedo figures; sometimes just the visible portion of the spectrum
 
is considered, sometimes the totality of wavelengths in the solar
 
spectrum. '' 
 
  
==References==
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[http://jeff.medkeff.com/astro/lunar/obs_tech/albedo.htm Jeff Medkeff's notes on lunar albedo]
''This article is based on NASA's [[NASA SP-7|Dictionary of Technical Terms for Aerospace Use]]''
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[[Category%3ADefinitions]]
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{{Physics Stub}}
[[Category%3ANASA SP-7]]
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[[Category Physics]]

Revision as of 09:23, 14 June 2007

See the section on Albedo for the basic definition. For the Moon, the average albedo for the solar spectrum across the lunar surface is 0.12 (i.e. only 12% of incident sunlight is reflected back, and the remaining 88% is absorbed). From the Apollo missions it's known that a substantial portion of this reflected light is sent directly back at the Sun, so we never see it from Earth. At the angles we can see the Moon appears even darker, with an effective visual albedo of 8% or less.

Individual features on the Moon have visual albedos that range from under 10% (the dark mare regions) to as high as 25-30% for bright ejecta and highland regions.

References

Jeff Medkeff's notes on lunar albedo

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Category Physics