There is a whole series of phenomena, either natural or artificial which do not have any
extraterrestrial visitors features about them. These phenomena are sometimes called upon rightly,
or wrongly, as the cause of a UFO report, or the as cause of all UFO reports. Here is some information
on these very terrestrial phenomena, including descriptions of their features. In connection with
UFO reports, this enables you to check if a sighting can or cannot be explained by one of these
commonplace causes. here is something about...
Those "invisible UFOs" that are only detected in infra-red: make no mistake
