If we ever encounter alien life, most probable is either: Microbial or other primitive life (carbon-based or otherwise). Or remains of some type of civilizati

If we ever encounter alien life, most probable is either: Microbial or other primitive life (carbon-based or otherwise). Or remains of some type of civilization. Like Maya ruins, or a Voyager-style probe that was launched 100k+ years ago. Both very difficult to detect from a distance. Or they'd have to come to us. Not sure that would be a good thing...