I remember several years ago having a dicussion with a co-worker, who happened to be an associate Baptist Minister(he is now a Minister at a one of the local churches where I live), about such an event.

I asked him what would be the reaction by the Church to signal detected from an alien civilization. He said that he wouldn't believe it because it was clearly written in the Bible that God created Man in his own image, so any signal would be a hoax. He did leave open the possibility of signal being sent by God to inform the world of the coming of Jesus as per the Book of Revelation.

I asked him if actual aliens showed up and presented themselves. What would be the reaction then? Then he said - "well if they show up in person, the church would be there to teach them about Jesus and how they(the aliens) could be saved thru his grace".

How can you argue with that answer! Amazing isn't it.