If you have a steel container with steam in it and put it in the freezer the steam will condense and then form ice will it not? And if you put the same container in space in heavy shadow the steam will condense and then form ice also? The first example is explained by slower outside particles taking energy from the container and the inside particles mainly isn't it? The second example is explained by heat radiation mainly isn't it? So why, in this second example, do the vibrations between the steam atoms decay to produce heat radiation where there are no outside atoms to steal their energy?