Okay, some basic physics:
The temperature of a spherical object, evenly heated by incident sunlight and cooling by reradiation, is given by the equation:
T = Ts x ([1-A]/4)^0.25 x (Rs/d)^0.5
where Ts and Rs are the temperature and radius of the sun, A is the albedo and d is the distance from the Sun. You can find this in any basic astronomy textbook, since it relates to planetary temperatures.
Plug in the numbers for an object that reflects about a third of incoming radiation (not particularly shiny) and you find that:
T ~ 250K
Well below freezing.
An object needs to be pretty much black as asphalt (albedo 8%) to raise its equilibrium temperature to freezing, at Earth's distance from the Sun.
Grant Hutchison
Last edited by grant hutchison; 01-August-2007 at 10:09 PM..
Reason: readability and correct typo in equation
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