How hot is the sky?

pkalmond

An object (a tin can for example) orbiting the Sun at about the same distance as the Earth would be what temperature?

davenn

This is really not a question about the sky is it :)

In any region close to the Earth, the temperature can vary from about -160ºC to over 200ºC, based on Table 11-43 "Typical Operating Temperature Ranges for Selected Spacecraft Components," from "Space Mission Analysis and Design," Wertz and Larson (eds) Kluwer 1999, ISBN 1884883108.

the variation depends on if it is sunlit or shaded
when you get away from any thermal influence of the sun or other body, ie. deep space, the temperature drops to the cosmic background radiation temp of ~ 4 K

Dave

mrspeedybob

Sure it's a question about the sky. If the earth is at a stable temperature that means that it absorbs about as much energy from it's surroundings (the sky) as it emits.

Earth is at thermal equilibrium with with it's surroundings (more or less), so when the tin can is in thermal equilibrium it will be at the same average temperature.

pkalmond	How hot is the sky? Tweet An object (a tin can for example) orbiting the Sun at about the same distance as the Earth would be what temperature?

mrspeedybob	Sure it's a question about the sky. If the earth is at a stable temperature that means that it absorbs about as much energy from it's surroundings (the sky) as it emits. Earth is at thermal equilibrium with with it's surroundings (more or less), so when the tin can is in thermal equilibrium it will be at the same average temperature.