Is it possible to observe a satellite orbiting a distant exoplanet? If its possible, it would seem to indicate that we have found intelligent life on that planet, since you need advanced technology to send a satellite to orbit.
How could you possibly observe a satellite on an exoplanet? There are 3 ways that I could see it being done. I'm going to assume you are talking about satellite similar to what we have now, there are objects conceived of in Science Fiction that could be more easily seen.
- Look for the satellite when it passes in front of the sun. (Occultation)
- Direct observation
- Looking for its communication patterns.
Occultation- This would basically look the same as a space rock, so it's not very likely to work.
Direct Observation- This would require a telescope that is enormous. It's more likely we would see ground objects than satellites, as they are much larger typically.
Communication- This one is possible, but typically satellites are highly focused on their home planet. Signals from the ground tend to be more powerful, and less directional. It could be that we would just get lucky, but aside from that, I don't think it would happen.
Bottom line is, there's easier ways to search for extra terrestrial life.