The rating system is interesting however, it may not be accurate enough, and too much visuals can disturb users reading news
How will you differentiate between credible news and just big news (as they both translate to bigger planets) – ensure the news aspect of the idea takes focus over visuals
Space ship theme could make the content of the articles seem a bit unreliable, or belittled. Ex) How would a story on war or terrorism look through a spaceship’s dashboard
Consider even more implementation ex) Planets colour based upon credibility, size based upon number of views, position based upon article age. Or Connectivity and proximity of planets based upon hyperlinked articles or related posts.
A user should still be able to quickly navigate to articles of interest
Perhaps consider simply applying visual idea to an existing forum or network rather than providing a stand-alone application.