posted on Dec, 20 2010 @ 10:36 AM
reply to post by XyZeR
See this thread
for a general description.
The important thing to remember is that when we talk about temperature (as in, "how hot is it outside?") on Earth, we are talking about the
temperature of the air
. In space - whether you're on the Moon or just in Earth orbit, there's no air, so temperature refers to how hot a
given surface is
. This, in turn, is determined by how much radiant energy (i.e. sunlight) it reflects, how much it absorbs, and how much it
re-radiates to space when the sun's not shining on it (remember that half of the surface of any
object is facing away from the sun at any
For example, here
is a typical object rotating in a vacuum at the same average distance from the
sun as an astronaut on the Moon. This object reflects ~37% of the light that falls on it. It absorbs the rest, but when the sun-warmed side rotates
into shadow, it reradiates the energy out into space. This energy transfer results in an average temperature of 15C (59F).
The Apollo Hasselblad cameras were heavily modified, and given a silvery finish to reduce absorption.
) Residual heat conducted to the interior and kept the film from getting too cold.