GEOL 212 Study Guide - Quiz Guide: Solar Luminosity, Horse Length
26 Dec 2017
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Effective temperature: the ideal temperature at which a planet precisely re-radiates all of the energy it receives from the sun. Where: l = solar luminosity = 3. 846*1026 w m-2 k-4, d = distance from sun, = the stefan-boltzman constant = 5. 6704 * 10-8 w. Thus, in our solar system, the only real variable in computing effective temperature is distance from the sun. If we treated real planets like idealized black-bodies, we get these effective temperature: venus: 327 k, earth: 279 k, mars: 225 k. Not crazy sounding except when you consider that in reality, these planets don"t absorb all of the solar radiation that hits them. Albedo: however, to know incoming solar radiation, we must also consider albedo, the amount of radiation reflected back into space. Clouds and surface features like ice caps have high albedo. Likewise: reflective icy worlds like enceladus have high albedo, dark worlds like mercuryhave low albedo.
