“After a lifetime in this subject, I have concluded that the extraterrestrial hypothesis is one reasonable tentative approach to putting the best-documented and most puzzling UFO reports into a scientifically defensible conceptual framework. By such reports I mean those with credible multiple or independent witnesses, instrumented observations, and physical evidence.” MeanSubjectsApproachEvidenceIndependentLifetimeObservationWitnessReasonableReportsMultipleHypothesisFrameworkUfoCrediblePuzzlingExtraterrestrialConceptual Framework Author:Jerome Clark