Three Kinds of Encounters

The Center for UFO Studies categorizes the witnesses as "Close Encounters" of the first, second, or third kind based on analyzing the amount of interaction with UFO's contacts. Encounters of the first kind are usually those reports of objects in the sky or unexplained lights. The famous Hudson Valley UFO sightings fall into[1] this category. The UFO having some kind of tangible[2] effect on the Earth environment, such as burn marks or radioactivity[3] marks belongs to the second kind. Close encounters of the third kind include the reports of interaction between the witnesses and the crew of the alien spaceship.

There are also a group of reports that can be termed as " alien abductions". There are many people who claim that the occupants actually forced them aboard[4] a UFO. Typically the subjects are examined by the aliens, then released[5]. While these reports are rare when compared to the number of close encounters of the first or second kind, many people from different walks of life[6] have reported this strange experience.