[appusviews]

Without having an atmposhere, I guess, our earth might have been as hot as moon's surface in the day time (above 100C) and as cold as the same at night. My question is why up in the atmosphere, especially in the cloud level (for example cirrus clouds consists of ice crystals) the air is very cold (like -40 or above). Why does the sunshine not heating these ice crystals? How the temperature is maintained at very low temperature in this level? Second question is what is the temperatue in the upper space, due to direct solar radiation (for example on a satellite orbiting earth, when it is exposed to direct sunlight?

[Clough]

In answer to your first question, I would suggest checking out the information on the following site: Explanation of Atmospheric Stability/Instability - by Steve W. Woodruff

[Capuchin]

Heh, have you ever seen ice? It doesn't absorb light, just refracts and reflects it. The sun doesn't warm up the ice because it's not absorbed by it. There's nothing in the upper atmosphere that would absorb a large amount of EM energy. The lower atmosphere is warmer because the Earth absorbs the energy and then reradiates it at a lower wavelength, warming the air.

As for the temperature of a satellite, that would depend very much on the albedo. The albedo of the moon is 12% which is very low. That means that it absorbs 88% of the EM incident on it which is one reason it is so hot. The Earth's average albedo is around 30%.

I would suppose that satellites would have a low albedo also, as the solar panels are designed to have low albedo to collect more EM. Satellites are probably designed to have a low reflectivity, as this would affect the motion of the satellite due to radiation pressure, but this is just speculation. Different parts of a satellite would have different temperatures, depending on the material, though.