“Among the hundreds of so-called "UFO reports" each year, a sizable fraction of those clearly observed by reputable witnesses remain unexplained-and difficult to explain in conventional terms. There is a modicum of physical evidence, radar cases, residual effects, and some films-and photographs in support of the unexplained cases. Collectively, these cases constitute a genuine scientific mystery, badly in need of well-supported, systematic investigation.” NeedsYearsWellsFilmDifficultTermCasesSupportMysteryEffectsEvidencePhotographGenuineWitnessReportsInvestigationConventionalUfoFractionsSystematicRadarUnexplainedResidual Author:Richard Hall