Question

give reason:-
beyond the atmosphere the sky will look dark

Answer 1

Yaaa.... Bcozz... their is no atmospher so dipersion of light will not take place.. ,colour of sky is blue is due to the same reason..:)

Answer 2

So answer to your question is pretty simple.
I am sure that you must know about dispersion of light. So what happens is when white light enters earth's atmosphere then the atmosphere behave like a prism and spread light with higher frequency at the top layers as it enters deeper the blue light which has a low frequency compared to other spread and we see our sky look blue but there is no atmosphere to spread light outside earth so it seems to be darker.

Thanks for asking
Hope it will help