Question

why does the sky appear dark instead of blue to an astronaut

Answer 1

The appear dark instead of blue to an astronaut because actually it is dark the reason behind is that light doest not return back due to which it appear black. sky appear blue for us due to the scattering of light .

Answer 2

The sky appeared black to the astronaut because there is no atmosphere in the space and hence no particles with which the sunlight can be scatter and hence no light scatter so the sky appears black.

Hope it helps u.