Brilliant!
Comic book art happens to be a hobby of mine, nothing makes me happier. And it's nice to see someone else giving it a go.
You're definately on the right track. You haven't fallen into the trap of trying to cram too many panels on one page; everything's nice and big and chunky. The opening page sets the scene nicely, too. Very cinematic.
I like the second panel on page 2. Your guy looks suitably bemused. The lack of a background for that particular panel helps too.
Keep your speech bubbles flat and level for "normal" speech. There's also a neat trick you can do with 'em:
Your reader is going to be following each bubble in order, so position them in such a way that your reader sees the "key" elements of each panel when appropriate. Try stuffing the "I know where I'm not...." bubble in the corner, next to your planetary vista. Magic!
