Geometric albedo




Airless bodies





Stars shine intrinsically, but they can also reflect light. In a close binary star system polarimetry can be used to measure the light reflected from one star off another (and vice versa) and therefore also the geometric albedos of the two stars. This task has been accomplished for the two components of the Spica system, with the geometric albedo of Spica A and B being measured as 0.0361 and 0.0136 respectively.[2] The geometric albedos of stars are in general small, for the Sun a value of 0.001 is expected,[3] but for hotter of lower gravity (i.e. giant) stars the amount of reflected light is expected to be several times that of the stars in the Spica system.[4]

Equivalent definitions




NameBond albedoVisual geometric albedo
Mercury [6] [7] 0.088 0.088
0.142 0.142
Venus [8] [7] 0.76 0.76
0.689 0.689
Earth [9] [7] 0.306 0.306
0.434 0.434
Moon[10] [10] 0.11 0.11
0.12 0.12
Mars [11] [7] 0.25 0.25
0.17 0.17
Jupiter [12] [7] 0.503 0.503
0.538 0.538
Saturn [13] [7] 0.342 0.342
0.499 0.499
Enceladus[14] 0.8 0.8
1.4 1.4
Uranus [15] [7] 0.300 0.3
0.488 0.488
Neptune [16] [7] 0.290 0.29
0.442 0.442
Pluto 0.4 0.4
0.440.61 0.44
Eris 0.96 0.96

See also


  • NASA JPL glossary
  1. See for example this discussion of Lunar albedo Archived April 13, 2009, at the Wayback Machine by Jeff Medkeff.
  2. Bailey, Jeremy; Cotton, Daniel V; Kedziora-Chudczer, Lucyna; De Horta, Ain; Maybour, Darren (2019-04-01). "Polarized reflected light from the Spica binary system". Nature Astronomy. 3 (7): 636–641. arXiv:1904.01195. Bibcode:2019NatAs...3..636B. doi:10.1038/s41550-019-0738-7.
  3. Gilbert, Lachlan (2019-04-02). "Scientists prove that binary stars reflect light from one another". UNSW Newsroom. UNSW. Retrieved 2019-04-02.
  5. Albedo of the Earth
  6. Mallama, Anthony (2017). "The spherical bolometric albedo for planet Mercury". arXiv:1703.02670.
  7. Mallama, Anthony; Krobusek, Bruce; Pavlov, Hristo (2017). "Comprehensive wide-band magnitudes and albedos for the planets, with applications to exo-planets and Planet Nine". Icarus. 282: 19–33. Bibcode:2017Icar..282...19M. doi:10.1016/j.icarus.2016.09.023.
  8. Haus, R.; et al. (July 2016). "Radiative energy balance of Venus based on improved models of the middle and lower atmosphere". Icarus. 272: 178–205. Bibcode:2016Icar..272..178H. doi:10.1016/j.icarus.2016.02.048.
  11. Mars Fact Sheet, NASA
  12. Li, Liming; et al. (2018). "Less absorbed solar energy and more internal heat for Jupiter". Nature Communications. 9: 3709. Bibcode:2018NatCo...9.3709L. doi:10.1038/s41467-018-06107-2. PMC 6137063. PMID 30213944.
  13. Hanel, R.A.; et al. (1983). "Albedo, internal heat flux, and energy balance of Saturn". Icarus. 53: 262. Bibcode:1983Icar...53..262H. doi:10.1016/0019-1035(83)90147-1.
  14. See the discussion here for explanation of this unusual value above one.
  15. Pearl, J.C.; et al. (1990). "The albedo, effective temperature, and energy balance of Uranus, as determined from Voyager IRIS data". Icarus. 84: 12–28. Bibcode:1990Icar...84...12P. doi:10.1016/0019-1035(90)90155-3.
  16. Pearl, J.C.; et al. (1991). "The albedo, effective temperature, and energy balance of Neptune, as determined from Voyager data". J. Geophys. Res. 96: 18, 921–18, 930. Bibcode:1991JGR....9618921P. doi:10.1029/91JA01087.