Fred and Scott, Cambridge asked:
If outer space is really cold, and the Sun is really hot, how close would you have to get to the Sun in order to be about room temperature?
[We put this question to Carolin Crawford as part of the Planets and Cosmology show]
Carolin Crawford: Room temperature where on the Earth?
Chris: They donít specify, so I guess you have full degrees of freedom, if youíll pardon the pun.
Carolin: Itís difficult, because as you go up from the surface of the Earth, you get colder. Also, on the side of the Earth facing away from the Sun it will be different from the day side. Itís actually a very difficult question to answer as thereís so many different ways to approach it.
Chris: Recently there was a Swedish space walk, and they were talking about how when people are in space they must wear reflective space suits; because if theyíre in the full glare of the Sun their body will quickly heat up to boiling point. In the dark side though, itís very cold because you radiate the heat straight away again. So it is a difficult question to answer, because if youíre having sunlight hitting you, you soak up a lot of radiation, and if youíre out of direct sunlight, youíre not.
Carolin: Also, if you think about aeroplanes, you can see the condensation freezing on the outside of the aeroplane, and although youíre above the clouds, youíre still nowhere near space.