You make a valid point (although another counter-argument has already been given. But speaking purely in terms of human eye sensitivity this has been confirmed

You make a valid point (although another counter-argument has already been given. But speaking purely in terms of human eye sensitivity this has been confirmed in an indirect way at least: the faintest star visible to the human eye (under perfect conditions) is comparable in light intensity. EDIT: also, sky lanterns https://en.wikipedia.org/wiki/Sky_lantern https://en.wikipedia.org/wiki/Sky_lantern