If it were (always) a vaporized dirt clod, it could not start out up by the cloud. What else is available to vaporize, there? Water, of course, but we would ne

If it were (always) a vaporized dirt clod, it could not start out up by the cloud. What else is available to vaporize, there? Water, of course, but we would need a different reason for its rarity then. A meteor? Rare enough. We should not assume there must be just one phenomenon that gets this name. There could easily be more than one. If there is more than one, a theory would not need to account for all observations; leftovers would need other theories.