Most people who have given the idea any reality based rational thought that there is indeed life on other Worlds would stand to reason that there would be intelligent life as well. Depending on how you define intelligent life, there will be many species much more intelligent than humans. Surely these other species will communicate different than we do and perhaps use electro-magnetic waves to send thoughts. Much different than voice speech communication of humans.

This is indeed a fascinating topic and it was recently brought up in an online think tank when on guest member stated; Mode of communication is as broad as the imagination. If they breath air they will almost certainly make some kind of sound, though. If they were aquatic, it could be more complex. I can't imagine a photogenic species evolving metabolism which would support intelligence, but depending on the elements making up the atmosphere, it could happen. Perhaps in a highly irradiated world.

All good points no doubt and in an atmosphere sound is an easy thing to have occur and thus communication could be made thru sound or waves which permeate thru the atmosphere. If the life lives in a sea of methane perhaps they will not use sound for communication or if they live in an area void of atmosphere they would not be able to use sound. The chances of a species living in an irradiated world is extremely likely, but it will be very difficult for us to visit them there to find out. What an interesting topic indeed. Perhaps we should consider more of this in 2006.