Musically the song rose from the bass line with the rest of the string and rhthym sections being layered on top. It had a sort of wierd sci-fi feel to it which threw up the song title.
As we move into the 21 century the rest of the world continually gets closer and our exposure to what we see as alien is ever increased. Our whole perception of this "threat" is stoked by a fire that burns within the media and those in government (or would be in government) to keep us scared and afraid so they can sell us more newspapers or pass more legislation.
The problem here is we can rarely get a reasoned debate on the subject as any negative aspects are so vastly highlighted they erode any toleration we may feel leaving each side further apart.