Searching African Skies

SarahWild

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First published by Jacana Media (Pty) Ltd in 2012 10 Orange Street Sunnyside Auckland Park 2092 South Africa +2711 628 3200 www.jacana.co.za Š Sarah Wild, 2012 All rights reserved.

ISBN 978-1-4314-0472-8 Also available as an e-book d-PDF ISBN 978-1-4314-0473-5 ePUB ISBN 978-1-4314-0474-2 mobi ISBN 978-1-4314-0484-1 Cover design by publicide Set in Arno Pro 12.5/14.3pt Job No. 001806 See a complete list of Jacana titles at www.jacana.co.za iv

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contents

Contents

Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii Chapter 1: Whatisradioastronomy?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Chapter 2: TheoriginsofradioastronomyinSouthAfrica . . . . . . . . . . . . 4 Chapter 3: ThehistoryofastronomyinSouthAfrica. . . . . . . . . . . . . . . . . 20 The amaXhosa and their understanding of the night sky (TembaEricMatomela). . . . . . . . . . . . . . . . . . . . . 34

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Chapter 4: SouthernAfricanLargeTelescope . . . . . . . . . . . . . . . . . . . . . . . . 38 Chapter 5: Backtobasics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Chapter 6: TheKAT-7andtheMeerKAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Chapter 7: AfricanSKA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Chapter 8: Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Internet connectivity for South Africa’s SKA bid (TobyShapshak) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Chapter 9: TheAfricanVLBINetwork. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Chapter 10: Benefits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Chapter 11: SKAscience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Chapter 12: Lookingtothefuture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

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Preface

preface

Preface

“S

owhatisthisSKAthinganyway?”Thatisthemost common question I’m asked at parties when someone falls back on the “What do you do?” icebreaker. When I say I’m a scienceandtechnologyeditor,thisisinevitablymetwithsome shoulder-surfing,theactofscanningthecrowdoversomeone’s shoulderlookingforbetterconversation.ThisisbecauseSouth Africa is rife with science stigma, the idea that science isn’t relevanttoadevelopingcountry,thatsciencemeanslaborious mathematical equations, and that science should stay out of everydayconversation–especiallyatparties.

And then the Square Kilometre Array (SKA) came along, andfinallypeoplehadaquestiontofillthatawkwardoh-dearI’m-talking-to-a-geeksilenceintheconversation.Bynow,many ix

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South Africans have heard about the SKA and know that we werebiddingagainstAustraliatohostit,andthatitwillbesplit betweenthetwocountries.SinceourcompetitorwasAustralia, SouthAfricansthoughtweshouldwinonprinciple–we’resick of Australia denting our national pride in rugby and cricket – even though those who’d heard about it didn’t actually know whatitwas.ThisiswhyIsitwiththeloadedquestion,“Whatis theSKA?” I finally have their attention, so I don’t want to delve into theoriginsoftheuniverseorgravitationalradiation.Thatwill juststartthemshoulder-surfingagain.So,Isay:“Itwillbethe biggestscientificexperimentonEarth–aradiotelescopethat willbeabletodetectsignalsfromthebeginningoftheuniverse.” Thepersonnodswithsatisfaction;theynowhaveananswerthat theycanweaveintoanotherconversation.

Luckily,Iworkforanewspaper,whichmeansIhaveaplatform totellpeopleaboutthisexcitingproject,butthentherearethe dualpressuresofnewspaperspaceandnewsworthiness.Thatis whythisbookcameabout:totellthestoryofradioastronomy and how South Africa ended up bidding to host the largest scienceprojectintheworld.Thereismoretoitthanaglib,wellrehearsedon dittobeflungoutatparties–itisastoryofthe peoplebehindtheproject,someofwhomhavededicatedtheir lives to curiosity about the universe, others who have fought localdisinterestandinternationalcondescensiontomakeusa realcompetitorinthebid,andthentherearethosewhoselives willbeirreversiblychangedbySouthAfrica’sradioastronomy plans.Someofthemhaven’tevenmeteachother,buttheirlives arelinkedbyaradiotelescope,andbythefactthattheirstories areseldomtold.

WhenIfirstdecidedtowriteabookaboutSouthAfrica’sbid tohosttheSKA,peoplebrushedmeoff:“SouthAfricansaren’t interested in science”, “No one will want to read about that”, and so on. They are the same people who will then complain aboutthescarcityofskillsinthecountry,andthefactthatschool learnersdon’twanttotakeMathsandScienceassubjects.They x

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can’t see that all these problems – including the perception thatnoonewouldbeinterestedinreadingabookaboutSouth Africanscience–areconnected,anditallcomesbacktoscience stigma. How can we expect our children to be interested in scienceifwearen’t?

Manyyearsago,ItaughtPhysicstoschoollearnersbeforeI realised that I was a better journalist than physicist. The most commonproblemamongmystudentswasn’tthemaths;itwas thattheythoughtsciencewasboring.Thisbookattempts–you willhavetojudgewhetheritsucceeds–toshowyouwhyscience is interesting and relevant, why the SKA will change your life, andthatscienceisforeveryone,notjustforPhDs. Sarah Wild Johannesburg, July 2012

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Acknowledgements

acknowledgements

Acknowledgements

B

efore I started writing this book, I thought the acknowledgements section was a cunning device to get Aunt Margetoforgiveyouforforgettingherbirthday–andthatthe sectionwassolongbecauseauthors,oftenbeingratherdistracted creatures,forgotalotofbirthdays.

Inreality,writingabookisamammothtaskanditisimpossible to accomplish without the help of people who are willing to giveuptheirtimetotalktoyou,answerstupidquestionsand replywhenyoucheckthewordingoftheiranswer.Friendships are tested to their limits because, at best, you are only able to talk about your book and, at worst, you tend to make people readmultipledraftsofthemanuscript;andyourlovedonesare obligedtoputupwithyouwhenyouturnintoacoffee-addled xiii

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bleary-eyed,andlet’sbehonest,irrationalmonster.

So many thanks are deserved in many quarters. To all the peoplewhowerepreparedtogiveuptheirtimewhenI’msure theyhadbetterthingstodo:BrianWarner,PatriciaWhitelock, BernieFanaroff,JustinJonas,AdrianTiplady(aspecialthanks toAdrianforthefactthathestilltakesmyphonecalls),Frank Curtolo,PieterSnyman,KhotsoMokhele,RobAdamandforall thosewhoI’veforgottentomention.

Thisbookisarealsciencebookbecauseofthepeoplewhonot onlyletmecommandeerhoursoftheirtime,butalsochecked the scientific facts for me. It is not possible to extend enough gratitudefortheirexpertiseandkindness:DavidBuckley,Mike GaylardandGeorgeNicolson;LauraBezuidenhoutfromExpert Virtual Assistant Services for typing up hours of interview transcriptsonwhatwasalwaysshortnotice;TembaMatomela andTobyShapshakfortheircontributions–whichaddaspecial something to this book and it is richer for them; my editor, PeterBruce,forhavingfaithinmeandgivingmemorechances thanIdeserve;RehanaRossouwforunknowinglyshowingme the kind of journalist I wanted to be; and, importantly, Jack Lesageforbeingmyfriend.Abigthank-youmustalsogotothe Department of Science and Technology for seeing the book’s potential,andtoTommyMakhodefortakingmy(many)phone calls.

When I first pitched the idea of a popular science book, people – once again – told me that South Africans weren’t interestedinscience.ThankyoutoRussellClarke,SeanFraser andJacanaMediaforbeingasexcitedbythebookasIwas,and formakingmyideaareality.

My gratitude, too, to Cassidy Parker for all the tea and for perhapsbeingevenmoreexcitedaboutthebookthananyone; SimonFerreiraforrestoringmyfaiththatpeoplewouldactually read a science book; Ron Fogel: I hope you’re still my friend after the lengths I pushed our friendship to by making you readseveraldraftsofthewholebook;ClaraVaughan,themost mighty Ming, your friendship (not to mention the chocolate) xiv

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keptmesane–well,relativelyanyway.Myfamily,andespecially mymom,forlisteningtometalkaboutthisbooknon-stopand interspersingmychatteringwith“youcandoit”.

AndfinallyPdW.Ononehand,youweremygreatestsupport, bouncer-offofideasandcomrade-in-arms,andIcouldn’thave done this without you. On the other hand, damn you. You ruinedmylife–thiswasyouridea!

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whatisradioastronomy?

1

What is radio astronomy?

I

tis1931,andanAmericanradioengineersitsinfront of reams of paper, wondering if he is losing his mind, if there is something wrong with his instruments, or both. He adjusts hisglassesandrunsahandoverhisprematurelybaldinghead. Onpaper,hisjobissimple:findoutwhatcausesinterferenceon transoceanic radio communications, specifically long-distance, short-wave communications. In real life, the task is somewhat morecomplicated.

Karl Jansky, an employee of the Bell Corporation, has isolated two aspects of the interference: nearby and distant thunderstorms. But there is something else. It plays through his instrumentation like a supersonic tinnitus, a static that is sometimesthere,sometimesnot.

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Hehasbuiltanantennatomeasureradiowavesof20.5MHz, rotatingonfourFordModel-Ttyres.Thatway,hecanfindthis mysterious source of static, which seems to radiate from all directions.

Ifyouhaveanimageofasuper-slinky,sexy,rotatingapparatus, its slicked chrome-and-ceramic veneer dreamily spinning like something out of 2001: A Space Odyssey, forget about it. This isthe1930s.Commonlycalled“Jansky’smerry-go-round”,itis aleviathan,eveninitsowntime.Thirty-five-and-a-halfmetres inlength,theradio-wavereceiverisaseriesofenormouscross barsandsquaremetalframes,andtakes20minutestocomplete a360-degreerotation.

Closetothedevice,Janskysitsinaseparateshed,staringat thedatafromhisanaloguepen-and-papermachine.It’sthere–a variablehissthatpeaksonceaday.

Fivehundredyearsago,peoplethoughtthattheuniverse– inwhichtheEarthwastheprestigiouscentrepiece–comprised enormousspheres,movingtogetherinmathematicalharmony. Musica Universalis, the music of the spheres, was ancient philosophy,ratherthanactualmusic.

Whilemostscholarsdealtwiththisonametaphysicallevel, JohannesKepler–whoselawsofplanetarymotiondescribethe ellipticalorbitsofplanetsaroundtheSun–believedthatthey really made music, singing like half-filled wine glasses played withamoistenedfinger.Amixtureofreligionandscience,these spheressungthemusicoftheheavens.

According to Kepler, celestial bodies orbited each other at a fixed distance, which corresponded to a specific pitch, in thesamewaythatastringofacertainlengthonaviolinelicits a certain note. All these notes were weaved into a pattern of proportion,adivinepatternthatdeterminedtheuniverse.

Now,whileKeplerwasonthemarkaboutthemaths,hewas abitconfusedaboutthemusic.

Tangentially,whiletheancientswerewrongaboutanumber ofthings,suchasaGeocentricEarthandthehealthbenefitsof 2

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leeches,theywerehalfrightaboutthemusicofthespheres.

Initially, Jansky thought the static was originating from the Sunbecauseoftheundulatingnatureofthemaximumintensity. Butitdidn’tfitwiththe24-hoursolarday–withpureobtuseness, thesignalrepeatedevery23hoursand56minutes,insyncwith thesiderealday,whichismeasuredviatheEarth’srotationwith respecttoafixedextrasolarobject.

What Jansky had in fact stumbled upon was radio waves emittedbytheMilkyWay. Nowthe1930swereatoughtimetofindfundingforlarge experimentalscienceprojects.TheGreatDepressionhadstruck theworldinthelate1920sandnoonehadmoneytospend,so –althoughJanskypublishedhisfindingsin1933–thediscovery laydormantforanumberofyears.

HetriedtoconvinceBellLaboratoriestobuildanevenbigger antenna,butexperimentalphysicspaledincomparisontothe demandsofabottomline,andJanskywasredeployedwithinthe company.

Ittookdecadesforscientiststodiscoverthatothercelestial bodies emitted radio waves at other frequencies, but the inventionofJansky’smerry-go-roundformedthefoundationof thenewdisciplinewehavecometoknowasradioastronomy. Stars, galaxies, pulsars, quasars – they all emit radio waves of differentfrequencies.

Traditional astronomy used, and still uses, optics to see into outer space, but the range of the visible spectrum – the seven colours that the human eye can see – forms only a tiny part of the electromagnetic spectrum. Radio waves occupy a largeportionofthespectrum,whichmeansthatyoucandetect a greater variety of wave and can gain fresh insight into the universe.Bycollectingandcollatingthedatafromthedifferent electromagnetic-radiationfrequencybands,weareabletomap outthedarkrecessesbeyondtheEarth,likeblindcartographers listeningtothesoundsoftheuniverse.

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The origins of radio astronomy in South Africa

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The origins of radio astronomy in South Africa

I

t’sallAmerica’sfault.IfAustraliaislookingforsomeone toblameforitsSquareKilometreArraycompetition,itshould blametheUnitedStates.Theexistenceofradioastronomyasa disciplineinSouthAfricaisactuallythankstotheUnitedStates’ National Aeronautics and Space Administration (Nasa). Until theKAT-7wasbuiltintheKarooin2010,thecountry’sfirstand onlyradioastronomyobservatorywasonceNasa’sDeepSpace Station 51, nestled in the hills of Hartbeeshoek, Gauteng. It soundslikesomethingoutofaColdWarspymovie,oratleasta science-fictionthrillerinvolvingaliensandArmageddon.

Well,itwastheColdWar,andtheRussianshadfiredthefirst Space Race salvo in 1957 by launching the satellite Sputnik 1 into space. In 1960, the then Union of South Africa’s Council 4

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for Scientific and Industrial Research (CSIR) entered into an agreement with fledgling Nasa to host one of its Deep Space Stationsinthecountry,totrackAmericanautomatedlunarand planetaryprobes.

Satellite and rocket launching is a risky business, and the spacecraftneedstobetrackedthroughoutitslaunch.Butifit’s launchedintheUnitedStates,theAmericansdon’thaveeyeson theothersideoftheworldtowatchitsmovements.SoNasa’sJet Propulsion Laboratory established three Deep Space Stations, oneinSouthAfrica,andanothertwoinCaliforniaandAustralia. Thestationswereapproximately120degreesapartinlongitude andeffectivelydividedtheEarth’srotationintothirds,providing continuousandoverlappingcoverage.

Not to sound esoteric, but planetary motion also played a role in the establishment of tracking stations in the Southern Hemisphere.Inthe1960s,theinnerplanetsouttoMarsallhad southerlydeclinations,whichmeantthatifaprobewassentto Mars,itwouldremainveryfarsouthformonthsatatime.Asa result,itwasonlypossibletocontinuouslytrackspacecraft– and sometimesMars– byhavingastationinSouthAfricaratherthan Europe. The Southern Hemisphere doesn’t permanently have this natural advantage over the north. Planetary declinations are cyclical. Through a confluence of circumstances – lucky circumstances for South Africa – the planets were favouring SouthernHemisphereobservationduringthe1960sandearly 1970s.

WithoutNasa’sinvolvement,itisunlikelySouthAfricawould havehadaradioastronomyprogrammeatall.Attheveryleast, thecountrywouldn’tbeasadvancedinthisfieldasitistoday.

Thepeopleholdingthepursestringsinthelate1950sthought thatAustraliawastoofaradvancedinradioastronomyforSouth Africatobetrulycompetitive.Itisalsoworthnotingthat,just asitistoday,radioastronomyisaratherexpensivefieldtobe involvedin.

Australia’s competitiveness dates back to the post-Second 5

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World War period. Both South Africa and Australia were building radar systems because, as Commonwealth countries, theyhaddevelopedradarinconjunctionwithradarspecialistsin theUnitedKingdomtodefendtheirrespectivecoastlinesagainst attack.Radar,shortforradiodetectionandranging,worksby bouncing radio waves off objects to determine their location, directionandspeed,andyouneedbotharadiotransmitterand areceiver.

Radio astronomy uses similar techniques, except that it doesn’t need a transmitter. Celestial objects, which generate a widevarietyofnaturalradiosignals,arethetransmitters,andthe receiversneedtooperateacrossarangeoffrequencies.

After the Second World War, there was a surplus of radar equipmentandasurprisingdiscoveryhadthrustKarlJansky’s cosmic radio waves into the spotlight. British physicist James StephenHeyhadbeentaskedwithdevisingradaranti-jamming methodsduringthewar.InFebruary1942,hereceivedreports of severe noise interfering with the Allies’ anti-aircraft radars. At first, he thought it was caused by crafty radar-jamming techniques or interference by German forces, but after some discussion with the Royal Society of London for Improving NaturalKnowledge,herealiseditwasradiationfromtheSun. Butbecauseitwaswartimeand“keepingmum”wastheorderof theday,Heywasnotallowedtopublishhisdiscoveryuntilafter thewar.

In this post-war period, Australia got an impressive head start in radio astronomy. The country had a number of radar specialists, and unlike countries such as the United Kingdom and the Netherlands, there was little organised academic research.Whilethismightsoundlikesomethingthatmighthold backacademicinquiry,itisn’t.Itmeantthatpeoplewithradar skills who were interested in radio astronomy could just start tacklingresearchproblems,withoutithavingtobecoordinated intouniversitygroupsandlimpingthroughanobstaclecourseof academicbureaucracy.

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IfyouhaveadiscussionwithanyoneinSouthAfrica’sradio astronomycommunityaboutthehistoryofthediscipline,they willtellyoutospeaktoGeorge.Orelsetheywillstarttellingyou stories, and interspersing them with comments such as, “You needtocheckwithGeorgeaboutthedates.He’llremember”or “Georgehasagoodmemoryforhowthingswentforward”.

SowhenyoufinallymeetDrGeorgeNicolson,heisabitof asurprise.ThegrandfatherofSouthAfricanastronomy–who was the first employee at Nasa’s deep space tracking station and the Hartebeesthoek Radio Astronomy Observatory’s (HartRAO)firstdirector–hasashockofwhitehair,blueeyes thattwinkleasbrightlyasthestarshe’sspenthislifelookingat, andamischievoussmile.

ThereasonpeoplewilldirectyoutoDrNicolsonisbecause hewasthere,helivedtheearlydaysofradioastronomy.So,when askedaboutAustralia’sprowessatthattime,heisunequivocal: “Theywereundoubtedlyworldleaders,intermsofpublications, numberofpeopletheyhadworkinginradioastronomyandthe qualityofworkthattheyweredoing.”

Because of this, the first president of the CSIR, Dr Basil Schonland – who also led the development of South Africa’s radarsystem–believedthecountryhadnochanceofcatching upwithAustralia,andshouldinsteadconcentrateonsomething that was unique to South Africa, such as using radar to study lightningbecausethecountryhassuchahighincidenceofthe phenomenon.

Nasa’s Deep Space Station 51, however, removed the impediments of funding and Australia’s competitiveness. The constrained budget was no longer an issue because Nasa was bankrollingtheinfrastructure.And,intheSpaceRace,USpride was on the line, so money didn’t seem too difficult to come by. The space agency built a 26-metre dish in Hartbeeshoek’s verdant hills, far away from possible interference. It operated in the 960 MHz frequency range, designed for signals with a wavelengthofabout30centimetres.Theonlywaytogetthere, 7

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fromeitherPretoriaorJohannesburg,wasalongdirtroads.

Concurrently, Rhodes University in Grahamstown had started its own mini radio astronomy programme, by using conventionalshortwavecommunicationsreceiversandlow-cost high-frequency wire antennas, which further diluted the cost threatofthecountrybecominginvolvedinradioastronomy.

Nasa provided the skeleton for radio astronomy in South Africa,anditwasliterallyaskeleton.Whatnowappearstobea handsomeparabolicdishcomprised,inthosedays,aseemingly flimsy wire mesh surface. “When you looked at the dish, you justlookedstraightthroughit,”DrNicolsonsays.“Itwasquitea spiderystructureanditwentthroughvariousupgradesoverthe years.”

But,inanexampleofwhyyoushouldn’tjudgeabookbyits cover,that“spidery”telescopealsohousedstate-of-the-artNasa technology.ThedealbrokeredbetweenNasaandtheCSIR–the council’s National Institute for Telecommunications Research in Johannesburg was responsible for the tracking station – statedthataslongasitdidn’tdisruptthedish’sprimarytracking functionandduties,thedishcouldbeusedforradioastronomy.

Notthatthereweremanypeoplewhocoulduseitforradio astronomy – there was only Dr Nicolson. He had originally workedfortheCSIR,butwastransferredtotheHartebeesthoek facilityas“basicallytheirfirstemployee”.

“Theonethingthedirectorofourinstitute[DrFrankHewitt] impressedonmerightfromthebeginningwasthatitwasgoing to be a one-man programme. He said that I had to be careful to choose projects that people with greater resources couldn’t completeinashorterperiodoftime,”DrNicolsonsays.

So, as part of his MSc degree, he began a survey of the SouthernGalacticplaneat960MHz.“SoIinitiallystartedoff by completing the survey of the southern Milky Way galaxy, preparing for it in 1961, building the equipment in 1962 and carryingoutandanalysingalltheobservationsin1963.”Amore 8

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extensive survey had been undertaken by the Owens Valley RadioObservatoryinCalifornia,butbecauseofitsgeographic location, observations from the Southern Hemisphere were neededtofillingaps.

Backthen,in1961,radioastronomywasworldsawayfrom what it is now. These days it is such a complex discipline that nichespecialitieshavedeveloped:datamanagement,computer interfacing, data analysis, telescope construction, receiver technologies.

DrNicolsontakesamomenttothink,beforecommentingon thedifferencesbetweennascentandmodernradioastronomy. “Intheearlierdaysofradioastronomy,peoplehadtohavearange of skills. They were mostly physicists or engineers rather than astronomers,sotheyhadtolearnastronomyalongtheway.As radioastronomydeveloped,peoplebecamelessdependenton havingtechnicalskillstodoradioastronomy.Today,mostofthe world’sradioastronomersknowverylittleaboutthetechnical details.Theyrelyontheengineersandthoseastronomerswho havetechnicalknowledgeandwhohavedevelopedsystemsto providethemwithaworkinginstrument.Theyjustgetthedata thatstreamsout.”

These days, radio astronomy comprises a large number of specialists, who work in niches to synthesise this complex beast. Back in the 1960s, radio astronomers built their own instruments,andifsomethingdidn’tworktheyhadtofixit.

Aside from the fact that Nasa provided the 26-metre dish, there were other definite benefits to being affiliated with an organisationthatwastryingtoone-upitsRussiancompetitors. Foronething,therelationshipbroughtwithitthemostcuttingedgeandsensitivegadgetsavailable.

In 1964, Deep Space Station 51 changed its operating frequency from 960 MHz to 2290 MHz. While Nasa did this to improve its tracking capability, South Africa got caught in the slipstream of four-times-more sensitive equipment. The amplifier Nasa installed gave the country’s radio astronomy 9

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community proportional advantage because it made the dish moresensitiveinsomerespectsthananyotherradiotelescope intheworldoperatingatthatfrequencyrange.

However,thereceiveronthetelescopealsoneededafacelift andanewnoise-addingradiometer,which–throughnecessity becausetherewasn’treallyanyoneelsetodothejob–wasbuilt byDrNicolson.

Withanewoperatingfrequencyandmachinerysoadvanced itshouldhavewornaspacesuitandhadaspacecraftpowered by cold fusion, the lone radio astronomer/engineer needed a newproject.SoDrNicolsondecidedtoobservequasars,which hadrecentlybeendiscovered.Aquasar,otherwiseknownasa quasi-stellar radio source, is a region at the centre of a galaxy, usually a very young galaxy, and is one of the most luminous and energetic objects in the universe. Scientists believe that it surrounds a supermassive black hole that is so dense and has suchastronggravitationalpullthatnotevenlightcanescapeit. Quasarscanbeupto100timesbrighterthananentiregalaxy, brighterthanalltheMilkyWay’sstarspackedintoasmallregion.

Because of its location and sensitivity, the telescope also played an important part in the global Very Long Baseline Interferometry (VLBI) network, a radio astronomy technique thatinvolvesobservingasingleobjectthroughseveraltelescopes in different parts of the world simultaneously, so that all the telescopesactasonebigtelescope.Itfilledinalongitudinalgap intheSouthernHemisphere,andwastheonlyradiotelescope on the African continent (see Chapter 9: The African VLBI Network).

1 Andso12yearspassedinrelativepeace,withdifferentprojects, newspacecrafttotrackandradioastronomyprojectssneakedin whentheantennawasidle.Itshouldbenotedthatitisdifficult forthesleepyhillsofHartbeeshoektobeanythingbutpeaceful. 10

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