Hmm... I've commented on this already, but I'll admit it wasn't exactly a critique!
The larger stars in the sky are beautifuly done and nicely laid out, but I feel that the smaller stars are too uniform in size. There's very little variety in it as a background. You should try some areas with fewer stars, perhaps even some black space, to lighten it up a bit.
Also, the highlights on the planets and on the water are very cold and white for such a warm sunset. a tinge of yellow or orange at the edges would do a lot to tie the picture together.
The sunset itself is beautiful and I love the way you've faded it into the starscape. The colour choices for the sky are also as near perfect as anyone can get!
Nice composition you did there - the planets are definitely very well done, and the sunset looks great. I like the way you did the color blending from the warm colours near to the sun up into the night sky with cooler colors. Great job!
If I may, though: Considering the light source (the sun), the highlights on the planets go a bit too far - the shadowy side should be much wider, unless you add another star on top (for the sake of realism). Also, the hue of the light on the water does not match that of the sunset - it should be much warmer, it looks a bit off like this IMO. The starfield may also be a trifle too dense, but that's really personal preference