Unidentifiedphenomenainspace,intheEarth’satmosphere,andinwatersaretooimportanttoleavetheirexplorationtothemilitaryandscientificlaypersons.Theirproperscientificstudyisimportantforavarietyofreasons;inparticular,scientistsandthepublicatlargeneedtoknowthebasicfacts,tobeinformedaboutthewayevidenceisrecorded,andtounderstandthedifferencebeenreliableevidenceandfiction,aswellasbetweenplausibleexplanationsandfantasy.Withthisobjective,thebooksurveysthehistoryofUFOobservations,thevarietyofrecordedphenomena,andrecountstheeffortsofinvestigativecommissionsandtheirpublishedfindings.Althoughwildrumorsaredemystifiedintheprocess,thisisnotanexerciseinrumor-bashing.Anopenandatthesametimecriticalmindsetisthekey.Manynarrativesandhypothesisappearimplausiblerelativetoourpresentstateofknowledge;butthisaloneshouldnotleadtotheiroutrightexclusion.ThustheauthoralsopaysattentiontoUFOsightingsthathavesofareludedexplanationintermsofknownphysicsormeteorology.Herethereaderwillencountersomeofthemorespeculativebutscientificallytenableproposals,forexample,relatingtosuddenzigzagmotionwithoutapparentinertiaorrecognizablepropulsion,yetalwayswithaclearguidetotheirplausibility.Lastbutnotleast,thebookoutlinesplansandsuggestionsforfutureresearchcapableofrevealingtheexistenceandintentionsofextraterrestrialintelligences,outer-spaceengineers,ortechnologiessofarknownonlyfromsciencefiction.
