While reading Devereux's Earth Lights Revelation, I was struck by how many of these reports would be called UFOs in most other contexts. And, now, when UFO reports describe "lights", I can mostly see them as potential earth lights (because I prefer the possibility of earth lights over extraterrestrial visitation). MANY ball lightning accounts describe balls of light falling from clouds. Technically, I guess, a UFO could be an earth light or BL (and vice versa) because it's unidentified and flying, but popular culture has conditioned us to think UFO = "alien spaceship" or some such paranormal explanation. I'm flummoxed as to how to tease these overlapping object descriptions apart. I don't know that you can. This problem of making interpretative descriptions (including the conclusion within the account) could mean that we are missing stuff or heading towards a dead end. This is one reason why I wish ufologists would get back to following up accounts of lights in the sky instead of business about disclosure and exopolitics garbage. There may be something interesting yet to discover.