Permanently shaded regions don't get much below 25K, maybe up to 70K. http://lroc.sese.asu.edu/posts/979 http://lroc.sese.asu.edu/posts/979 Still good enough fo

Permanently shaded regions don't get much below 25K, maybe up to 70K. http://lroc.sese.asu.edu/posts/979 http://lroc.sese.asu.edu/posts/979 Still good enough for mercury of course.