Given the countless number of solar systems in the universe it is conceivable that there would be systems that could hold life far more advanced than we are and might have the possibility of stellar travel. I have always considered space as being infinite therefore I believe there would be many planets which support life as we know it and possibly even many supporting life as we are unaccustomed to possibility like silicon based life or some other. To think we are alone in the universe is just conceited and shallow thinking, or maybe religious thinking. Even thinking religiously one should consider that God in his infinite wisdom would not place all his egs in one basket.