There is a whole series of phenomena, either natural or artificial which have nothing to do with aliens, nothing to do with "the paranormal", and are not really unexplained. 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.
