1In1961,scientistssetupgigantic,sensitiveapparatustocollectradiowavesfromthefarreachesofspace,hopingtodiscoverinthemsomemathematicalpatternindicatingthatthewavesweresentoutbyotherintelligentbeings.Thefirstattemptfailed:butsomedaytheexperimentmaysucceed.

　　Whatreasonistheretothinkthatwemayactuallydetectintelligentlifeinouterspace?Tobeginwith,moderntheoriesofthedevelopmentofstarssuggestthatalmosteverystarhassomesortoffamilyofplanets.Soanystarlikeourwansun(andtherearebillionsofsuchstarsintheuniverse)islikelytohaveaplanetsituatedatsuchadistancethatitwouldreceiveaboutthesameamountofradiationastheearth.

　　Furthermore,suchaplanetwouldprobablyhavethesamegeneralcompositionasourown;so,allowingabillionyearsortwo—orthree—therewouldbeaverygoodchanceforlifetodevelop,ifcurrenttheoriesoftheoriginoflifearecorrect.

　　Butintelligentlife?Lifethathasreachedthestageofbeingabletosentradiowavesoutintospaceinadeliberatepattern?Ourownplanetmayhavebeeninexistenceforfivebillionyearsandmayhavehadlifeonitfortwobillion,butitisonlyinthelastfiftyyearsthatintelligentlifecapableofsendingradiowavesintospacehaslivedonearth.Fromthisitmightseemthateveniftherewerenotechnicalproblemsinvolved,thechanceofreceivingsignalsfromanyparticularearth-typeplanetwouldbeextremelysmall.

　　Thisdoesnotmeanthatintelligentlifeatourleveldoesnotexistsomewhere.Thereissuchanunimaginablenumberofstarsthat,evenatsuchmiserableodds,itseemscertainthattherearemillionofintelligentlifeformsscatteredthroughspace.Theonlytroubleis,nonemaybewithinhailingdistanceofus.Perhapsnoneeverwillbe;perhapstheappallingdistancesthatseparateusfromourfellowdenizensofthisuniversewillforeverremaintoogreattobeconquered.Andyetitisconceivablethatsomedaywemaycomeacrossoneofthemor,frighteningly,oneofthemmaycomeacrossus.Whatwouldtheybelike,theseextraterrestrialcreatures?

　　2TinyTongaLaunchesSpaceTourismPlan

　　Thetinypoverty-strickenSouthPacificstatefTongahasalwayshadseriousproblemsraisingmoney,andsoithasalwaysbeenentrepreneurial.IthissoldTonganpassportstoHongKongbusinessmen;itsoldpossiblesatellitebroadcastinglocationsinspace;itevenofficiallychangedtoadifferenttimezonetobethefirstcountrytowelcomethenewmillennium.1

　　NowTonga’slatestmoney-makingventureisaplantobecometheworldcenterofspacetourism.TheTongagovernmenthasmadeanagreementwithaUScompanytoallowittouseonofits170islandstolaunchrocketsthatwilltaketouristsonweek-longtripsintospaceatacostofUS$2millioneach.2

　　Forthisprice,spacetouristsreceive60days’trainingina“resortsetting”,followedbytheholidayofalifetimeorbitingtheEarth.3Twoastronautpilotsandfourastronauttouristswillmakethetrip.However,skepticssaythatthesebudgetsareinadequate.AlthoughtheypredictthatspacetourismwilleventuallybringanincomeofUS$10-20billionayear,theycalculatethatthebudgetof$8millionpertripwillnotbeenoughtopayfortherequiredtechnology.

　　Comparisonwiththecurrentspacetourismprogrammesuggeststhismathsmaybeaccurate.ToridetheRussianSoyuz(theonlytouristridecurrentlyav