I always thought that it was an interesting issue. If there are other beings in the universe, are they capable of "being saved?" They couldn't know Christ, since they are on other planets, so what does that mean for them? Also, why did everything in the Bible occur here on Earth? God created billions of planets, so was this his favorite? It must have been if he sent his only son to this planet.
Obviously, I intended these as rhetorical questions (I don't know that a response that is not highly speculative is possible).