The piece looks good - did you take down the first piece? I get the feeling that at some stage, I reviewed that as well and I seem to remember that most of the piece was obscured by the overzealous lighting effects. Still, that's been improved now and the piece has improved so much for that alone.
With the land layouts of Earth, I can pick out what looks like Africa on the right of the globe, but I'm unsure as to which land mass is around the equator on the left, there. Just a little pointer - if you're going to draw Earth, accuracy is nice, but not entirely necessary. Making rough shapes, to represent the land masses would have helped here, but that it a bit of nit picking.
I like the use of shading, but with the perspective of the sun, you would need to extend those shadows quite a bit, both on Earth and Mars, but mostly on Earth, just for accuracy's sake. I like that you've added various natural satellites. If you were to take another challenge on in the cosmos, perhaps you'd draw the four gas giants - Jupiter, Saturn, Neptune and Uranus, since they are all very different subjects and they have very different looks to them. Drawing with the sun behind you as the artist's viewpoint, could give you different shading looks, but it's all pretty academic.
[Review Request Club]
