I like the concept but the sig seems a bit bland. I suggest adding a border and re-tooling the text. The text seems to jump out too much imo, it draws the focal away from the planet. You might also consider adding some detail into the background. The planet seems a bit lonely without anything else but that may be what you're going for with the phrase "the void." It's really good for a first attempt though, and certainly better than my first.
Yeah Magnet pretty much nailed it...Planet needs Stars in the background and something to draw the eye away from the text (but not too much)
Just to add, your text on the right is actually pretty good and suits the rest of the sig. Be sure to keep the text in your mind, in terms of placement and stye, whilst making the sig and it won't end up looking like it was an afterthought.