this piece has loads of issues, first of all u have some strain pixels popping here and there.... the moons surface is way too bright, also the distorted dithering doesnt rly add to the picture,  u used lots of unnecessary colors for it ( yellow/ several greys), and it lacks of depth ( try using dark colors in the fore- and bright colors in the background)... also ur shading needs improvement, try defining volumes more accurate (like the  craters), the radio isnt shaded at all!!...also u should let ur objects cast shadows, so u can tell whats on and whats above the ground... the dithering on the suit is also way to grainy (such dithering should be used for rocky textures for instance, but not for soft textures like that of a space suit)... dont use dither where its not needed. whats up with the outlines?.... and most important: whats up with the background? have u ever looked at the sky at night? what do u see? light grey?!?!?.... some stars would be nice too....

heres an edit to give u an idea:

http://i992.photobucket.com/albums/af45/oooonek/moon.gif