This is an ending screen for a flash game I'm making.

This displays after the player breaks away from Earth's gravity and launches into space. The yellow speck will flicker and slowly move away from the planet, while congratulatory text is displayed on the top.
To be honest it looks a little bit better than I thought I was capable of at first, but I still don't think it looks like it was drawn by a true professional. Anybody have advice? In particular, I feel like the earth looks a bit too "blobby", but I'm having trouble adding detail to it that doesn't seem like random noise. Also, I feel like the space area could be done with more detail to seem more mysterious and fantastic.
Now that I'm typing it out, it occurs to me that my main problem with most of my art in general is that I don't know how to add detail that is believable and professional looking. I just draw in "blobs" and tend to leave it that way. Any help with this is appreciated. Thanks guys!