Looks much better in high res. Stars are so tiny they sometimes get lost in the upload. Good trick is to upload your starry image and if the stars are weak go back to your orginal and copy only the stars to a new layer, do the copies so they register in the same place. Set layer to screen or lighten till they get brighter, just keep adding layers till the show up well in your upload. You should lighten up the asteroid a bit too so we can see it better.

Nicely done.

Very nice concept.But the overall image looks a little empty.U can make the planet bigger or add some meteriods