Of biblical aliens

A friend commented that the bible mentions aliens. I was skeptical, so he made a comment about Jesus saying he was leaving Earth and going to tend his "other flocks". I pointed out that that was a rather vague reference if it did in fact mean aliens.

However, I was intrigued, and went to look it up. I think this is the passage he was referring to:

John 10:16 And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.

The Skeptic's Annotated Bible links this with an almost identical Book of Mormon passage, and says that there it refers to the Nephites. Not entirely convinced of the conclusion there, but it is certainly a fairly general statement, and could mean almost anything.