*That* is a reasonable response. I don't know what they are, but I know people have been seeing them for a long time. That alone makes them worthy of study, though not of interest to all people.
UFOs have changed a lot in the 100+ years of modern sightings. They seem to have kept up with technology, just a tad ahead of what is already flying out of Air Force bases. The people aboard the UFOs have also changed over the years, seeming to reflect types of persons found in society, all the way fromn NAZIs during the mid 1900s, to bio-scientists now. There are valid studies, mostly in the field of psychology.