I can't wait for the discovery of life on other planets. The amount of scrambling that our religions will have to do to explain it will be amusing.
How the hell did I miss this one...
My suspicion is that religions will isolate religion to Earth, essentially the response will be that religion was handed down to the people of Earth specifically, the idea that man was made in Gods image does not negate the argument that God could have made "martians" in the image of something else.
Basically the various "Bibles" are open ended documents designed to be adapted to whatever scenario arises, some people look at this as genius others look at it as an indication that it is fiction as imparting knowledge is a more precise process.
Besides if all that fails they will simply rewrite them as has been done in the past.