There might be more intel life in another planet(system)..No one knows for sure but u can certainly speculate..Rosewell case is a proof that there is certainly so called activities of alien kind in this planet..even though there have been conflicting reports about that particular incident, there r plenty of reasons to believe that we are not the only one in this universe. UFO's and USO's( Unidentified submersible objects) are kind of explainable natural phenomenon except around 5 % of total sightings reported are totally unexplainable. And ofcourse dude to vagueness of those unexplained incidents one will have to think the rationale and decide....( Like rosewell, keksburg,UFO sightings at US air base in england and so on) The most intriguig thing is why all these cases happen to occur only in heavily industrialised nations like america, japan, england and russia, why not in remote corners of nepal or even in kathmandu.. By sayin this let me remind you that US have tried to manufacture disc shaped miltary aircraft in the past.. so all these weird shaped UFO's might as well be human creation !!No one knows for sure coz there is sort of information vacuum in this field and speculations is our best hope for now. Abduction by aliens in my opionion is a creation of beautiful mind! I have met a few people who r into aliens and UFO's completely and they seem to look like something is wrong with them mentally...Its just a case of hallucination..