> And like most things, the moon will be close enough to a greybody that you could use the surface temperature as a first order approximation. No, it won't, an

> And like most things, the moon will be close enough to a greybody that you could use the surface temperature as a first order approximation. No, it won't, and no you can't. The OP already pointed out that the Moon is too cold for its blackbody radiation to reach the visible. All the visible light from the Moon is reflected from the Sun. The Sun's radiation's blackbody temperature is the ultimate limit, here, not the Moon's.