The Fight Toput a Monster Telescope on Mauna Kea Is Part of a Biggerwar Looming

AirSpaceMag.com

BigGlassandtheAgeofNewAstronomy

The fight toput a monster telescope on Mauna Kea is part of a biggerwar looming amongastronomers.

By Dennis Hollier

AirSpace Magazine| September 2016

The tallest island mountainin the world isHawaii’s Mauna Kea, wherethe thin atmosphere and absence of light pollutioncreate some of thebest observing conditions forastronomers. At the summit, 13 telescopes sit along a ridge of formationsthat have built up around volcanic vents. Theoldest telescope on site, and still the smallest, is theUniversity ofHawaii’s 2.2-meter (7.2-foot)UH88, built in 1968. MaunaKea is best known as the home of thetwin 10-meter Keck telescopes, whichsaw first light in the 1990sand remain two of the largest optical and infraredtelescopes in the world. Collectively,this baker’s dozenof observatories hasdominated ground-based astronomy forfour decades. But recently,Mauna Kea has becomeembroiled in a disputethat could radically alterthe future of astronomy, and serve asa cautionary example of whatwe might lose ifit keeps going downthis path.

In 2009, Mauna Keawas chosen as thesite for the ThirtyMeter Telescope, a mega-observatoryproposed by the CaliforniaInstitute ofTechnology, theUniversity of California, and national science agencies inJapan, Canada, India, and China. Its massive mirrorwill be made from 492 segments andhave 81 times thesensitivity of the Kecktelescopes. Ed Stone, a Caltech physics professor and the executive director of TMT (not to mentionformer director ofNASA’sJet Propulsion Laboratory), explainswhy scientists are pursuing a telescope more thanthree times the size of the biggest one currently on Mauna Kea:“If you want toseethe very first stars in theuniverse,” he says, “youneeda telescope of this class.” Keck has been able to observe a galaxythat existed about570 millionyears after the Big Bang, but it just isn’t capable of observingthe most distant stars, the firstones, which formed about400 million years after the creation of the universe.

“Another frontier that needs the collecting power of anew generation of instruments is the study of exoplanets,” Stone says.“Our challenge is developingthe technology and capabilityto study those planets—forinstance, to determine whethermicrobial life might have evolved on them.” Theseare the types offundamental questions the TMTshould be able toaddress. And yet, thegiant telescope may never be built.

In October 2014,as officials and construction crews headed tothe site for the ground-breakingceremony, a group of nativeHawaiian protesters blocked their accessto the summit and refusedto move until the projectwas stopped. Native Hawaiians considerMauna Kea a sacred site—manygenerations have returned tothe mountain to burythe piko, or umbilicalcords, of their newbornchildren (pikoalso means“mountain summit” in Hawaiian)—and havebeenvocal intheir opposition to buildingobservatories there for years.Hawaii’s governor, fearing violencemight break out, negotiated a temporary halt inthe construction. Then, lastDecember, the state’s supremecourt vacated the observatory’sbuilding permit, sending theapplication back to theland and resource agency for anewhearing.Though the telescope’s managersstill hope to build on Mauna Kea, theyalso fear a longlegal battle that theywill eventually lose, and have started to seriouslyconsidersites in Baja California,the Canary Islands, Chile,India, and China.

Some Hawaiians are also fightingthe extension of the entireobservatory complex’s 65-year lease on the summit, which expires on December 31,2033. Doug Simonsis the director of the3.6-meter Canada France Hawaii Telescope and former director of theGemini Observatory, which has twineight-meter telescopes onMauna Kea and inChile. He says thatwithout assurances that themaster lease will be extended, the agencies thatfund the observatories will be reluctant to investin improvements ornew instrumentation. In fact, someobservatories had already begun to change operations inpreparation for the ThirtyMeter.TMT’sJapanese partner operates Mauna Kea’seight-meter Subaru telescope, andhad started winnowing its instrumentation sothat it operates exclusively as a wide-field telescope in collaborationwith the new arrival. “Theyhaven’t gone so far downthe path that it’s irrecoverable,”Simons says. “But they have taken the moststeps of all the MaunaKea observatories in advanceof TMT’s arrival.” If thegiant telescope isn’t built, Subaruwill have to reconfigureagain to remain a meaningfulcontributor to astronomy. And ifthe native Hawaiians succeed,the entire scientific complex will be dismantled, and the landreturned to the state.

The controversy surrounding the TMT and its impact on theother Mauna Kea observatories seemlike a local story,but the struggle is alsosymbolic ofa broader problem.Over the past few decades,the field of astronomy has been dominated by efforts tobuild newer and bigger telescopes.The TMT is projectedto cost

$1.4 billion, and theother observatories being builtin this wave (allthree in Chile) comewith similar price tags.The Giant Magellan Telescope,which will actually houseseven 8.4-meter telescopes, willlikely exceed$1 billion.The staggeringly huge 39.3-meterEuropean Extremely Large Telescope, orE-ELT, isprojectedto cost $1.35 billion.And the relatively dainty8.4-meter Large Synoptic SurveyTelescope (LSST) will cost $650 million to construct, but the bill goes upover$1 billionwhen it includes operationfor the 10-year skysurvey the instrument isprojected to start in 2020.“A billion dollarsis pretty much theentryfee into this particulargame,” says Shrinivas Kulkarni,Caltech’s director of opticalobservatories.

With only an 18-inch mirror, Palomar Observatory’s first telescopemade historic discoveries for nearly 60 years. (Palomar/Caltech Archives)

Because Caltech is one of the primary partners of the Thirty Meterproject, part of Kulkarni’sjob is to overseethat investment. But even though he strongly supportsbuilding the observatory, he believes the trend towardthese massive and costlyprojects represents a sea change in how astronomyis practiced. Increasingly

Kulkarni says, the study of the universe has become the province of physicists—especially particle physicists—and theylook at the worldvery differently than astronomers do.

“Astronomers used to be the phenomenologists of theuniverse,” Kulkarni says. “Just asa plant biologiststudies plants of varioussorts anda zoologiststudies various sorts of animals, an astronomer does the same thing forthe universe. Wego and look for stars,for galaxies, for intergalacticmedia, and we catalogthem.We see how theenergy formed; what’s thelife-cycle of stars; what’sthe end product; what’sthe ecosystem. You couldalmost regard astronomers, likezoologists and biologists, primarily as explorers, as catalogers and explainers. That’s whatwe do.”

But two things changed that, he says.The first was the discovery of cosmic background radiation in the 1960s.This radiation, essentially the first lightin the universe, dates back tojust a few hundred thousand years afterthe Big Bang. In 1989, NASAlaunched COBE, the Cosmic Background Explorer,which enabledastronomers to begin seriouslyprobing its nature. COBE and several subsequent spacecraft,including Europe’s ongoing Planckmission, have mapped thedistribution of this radiationacross the universe. “Thediscovery of background radiationshowed the real linkbetween astronomy and basicphysics,” Kulkarni says.Even though the discoverywas largely driven by the techniques of astronomy,it fell to physiciststo explain the high-energyenvironment right after theBig Bang. Suddenly theentire universe was a laboratory for particle physicists.

This blending of physics and astronomywas initially aboon to bothfields. Kulkarni points out that itwas a theoretical physicist, Alan Guth,who came up with the ideaof cosmic inflation, oneof the central ideas of modern astronomy.

The second big change in astronomy was thediscovery of dark energy.In 1998, two groups of astrophysicists studying supernovasfound evidence that theuniverse wasn’t just expanding, but expanding atan accelerating rate. This NobelPrize-winning discovery led tothe postulation ofa form of energy thatwouldexplain the outward force. Darkenergy is now believed to account for more than 68 percent of the energy and matter in the universe. (Darkmatter makes up27 percent.Ordinary matter, the stuff you can see and detect, makes up the rest: less thanfive percent of the universe.)

Last year, native Hawaiianprotesters, who believe MaunaKea is sacred, blockedconstruction vehicles from the new telescope site. (HollyJohnson/Hawaii Herald Tribune viaAP)

These discoveries advancedour knowledge of the universetremendously. But they alsoforced physicists and astronomersto learn how tolive together, says Kulkarni.“The culture of particlephysics is different,” he says. “As much as astronomers are phenomenologists—explorers whowant to see thebreadth and diversityin the universe—physicists arethe exact opposite. They’rewhat we call reductionists.They try to reducethe complexity of theobservations of phenomena intoas few principles as possible.” The whole body of what we now call mechanics derives fromNewton’s second law of motion: Force equals masstimesacceleration.The predictive power of this kind of theorem has made physics theking of sciences, Kulkarnisays, and mathematics the queen. Unlike astronomy, thebasic impetus of physicsisn’t to discover somethingnew; it’s to developtheories to explain knownphenomena, then create experimentsto test those theories.Because of the growing influence of physics, the discipline’s method issteering the entire field of astronomy in that direction too.

Today,an enormous amount of money is beingspent on these grandexperiments—many of which aresimilar. “The Europeans arelaunching the space missioncalled Euclid, which, as the name implies, islooking at the geometry of space,” says Kulkarni.“Not to be outdone,in 2025, the U.S.is launching somethingcalled WFIRST, which will alsoproduce a geometry of the universe. And one of the main goals of LSST is to measurethe geometry of the universe.So, there’s beenan enormous investment of moneyinto these very large, high-profile,almost singularly focused, fundamentalexperiments.”

Those observations are bound to teach usa lot, butas Kulkarnisees it, the facilitiesrequired to do theexperiments are of such a scale that theylimit the amount of other types of astronomythat canbedone. Lost in all thiswill be the serendipitythat comes from basicexploration.

Although other astronomers may disagreewith Kulkarni about the severity of the problem, his basicpremise isn’t particularly controversial. Especiallycoming from someone at Caltech, says Doug Simons: “Look at the history of Palomar[Observatory] and Caltech, which has dominated the field of astronomylike no otherschool.Whodiscoveredquasars,forexample?ThatwassubstantiallydoneatCaltechandPalomar.Nobodyevenknewthatsuchobjectsexistedintheuniverse….Weknownowthatblackholespowerquasars,butwhen[DutchastronomerMaarten]Schmidtidentifiedthefirstquasar,QC273,itwasacompletelyunpredicted product of innovative observing at Caltech.That’s what [Kulkarni] is talking about:finding things youneverkneworeven imagined existed in the universe.”

But not everyone agrees withthe notion that big physics-basedprojects remove the chance forthe serendipity that Kulkarniyearns for. Ed Stone refutesthat idea by pointing tothe first detection of gravitationalwaves at the LaserInterferometer Gravitational-Wave Observatory, or LIGO. “I think that many astronomers nowbelieve—onceonewasdetectedforthefirsttime,andthemergingblackholesthatcauseditweredeterminedtobemuchmoremassivethanthemodelssuggested.Thatmeanswe’velearnedsomethingelseaboutnaturebesidesjustconfirmingEinstein’stheoryofgravity.So,inmanycases,anexperimentstartsoutansweringa physics question, but then begins to answerquestions having to do with astronomy and astrophysics.”

Even if you make thecase that massive, narrowly focusedobservatories like LIGO and TMTcontribute to basic exploration, buildingthem still affects therest of the field. Thebudgetary burden will fall on the existing stable of smaller,older telescopes. Certainly,that’s thecase on Mauna Kea, wherepart of the bargainto buildThirty Meter included shuttingdown some of theolder facilities. To free up operational funds fornew, larger facilities, the 2010 Astronomy and AstrophysicsDecadal Survey recommended closing 84 older ones.

This, of course, seemslike a perfectly sensibleattempt to prioritize projectsin the face of limited resources. “Sometimes thereis no other waythan to build a large instrument,” says Stone.“You just have tovery carefully choose which onesyou decide to do next. That’s whywe have the DecadalSurveys, which theNational Academy of Sciences does to advise [theNational Science Foundation] and NASA.”

The decision to shutdown smaller, older facilitiesmay make sense forbudgets, butnot necessarilyfor science. Rene Walterbos,who chairs the boardthat oversees the SloanDigital Sky Survey, points out that unlike thebig facilities that do particle physics research, telescopesdon’t become obsolete as they age. After theLarge Hadron Collider wasbuilt at CERN inGeneva, Switzerland, Fermi lab’sTevatron particle accelerator inIllinois was shut downbecause nonew researchcould bedoneat its lower energy levels.That’s simply not thecase for telescopes, Walterbossays. “In astronomy, any telescope cankeep observing.People stillfind useful things to do,even withvery small telescopes.”

If you’ve ever used a camera, youknow that themore you zoom, the narrower yourfield of visionbecomes. The small telescopes of the world may not see as far as their modern10-meter siblings, but theysee wider. That makes theolder generation of telescopes bettersuited for broad surveys of the sky.Walterbos points outthat the Sloan survey,which for the past 15 years has operatedtwo 2.5-meter telescopes inNew Mexico, hasbeen oneof the mostproductive astronomy programs inthe world. The Sloansurvey hasbeen systematicallycreating three-dimensional maps of a large portion of the universe, data that’smade public and usedfor research at other facilities. Indeed, oneof the main functions of smaller telescopes is to find new things for the TMTsand Kecks of the world to take a closer look at. At Mauna Kea,this collaboration is practically a matter of walking anewfindingacross the street. “That’s exactly right,”says Gary Davis, formerdirectorof the 3.8-meter UnitedKingdom Infrared Telescope. “A lot of the discoveries atUKIRT were followed uponGemini’s largertelescope.”

Another cost of shuttingdown older observatories ismore straightforward: There will be fewer facilities whereastronomers cando research.Many astronomy students and faculty are at universitiesthat haveno observatory;to conduct their research,they compete for timeelsewhere. But many of these new, large facilitiestend to be owned by groups of private universities, whichgive first dibs to their own scientists.

“People may look at TMT andsay,‘Well,that’s great, but we’ll neverget inthere,’ ” says Walterbos.“That’s a potential source forreal tension. Early in the next decade, the NSFwill have to figure out if they can afford tomake an investment and bea partner in that and, in return, provide accessto the community. Or willthey notbea player at all? The pressure on their budget is severe, and they havea very difficult job—as does the community asa whole—figuring out what thebalance will be.”

Another benefit of smaller telescopes is theflexibility for astronomers to be creative,says Davis, who left Mauna Keato work on the ambitious Square KilometreArray radio telescope being designed forlocations in Australia and South Africa. “That’swhere the real innovation happens, becauseit’scheaper to do thatinnovation on small telescopes.If I want totry some weird observingmode, it’s easier to do that ona telescope that costs $1.2 million ayear tooperate than one thatcosts tens of millions.”

Nowhere is the impact of the innovation at the smallertelescopes more obvious than on Mauna Kea. Whenever the issue of old versus new comes up, Doug Simons likesto pull outa list of observatories worldwide that had the biggest scientific impact in 2015.It’sa metric oneof his colleagues calculated by taking thenumber of publications that come outofa facility—ameasure of productivity—and multiplyingthat by the number of citations those publications receive—ameasure of influence. Thetwin Keck telescopes top thelist, but the next two are its sub-four-meterMauna Kea neighbors: CFHT and UKIRT, both of which have beenoperating for nearly 40 years.

That success, Simons says, islargely the result ofa willingness to take risks, particularly on instrumentation. In 1996, CFHTwas the first telescope toregularly support observations with adaptiveoptics, the use ofa high-speed, deformable mirror to cancel out the effects of atmospheric turbulence in real timeto get sharper images. “My first job aftergraduating from the University of Hawaiiwas asa resident astronomer at CFHT,” says Simons, “andI rememberthe ferocity of the debates back then at this ‘black magic’ technology….It wasn’t an easy decision, but we decided to goahead and pursue it atCFHT,and we were the first outof the starting blocks.It was a spectacularsuccess.” No major telescopetoday is built withoutadaptive optics.

More recently, CFHT invested inthe SITELLE, an instrument successfullytested last year that analyzesthe spectra of every objectin its view simultaneously. “SITELLEcan measure the spectra of complex fields in a couple of hours, which would takeconventional slit spectrometers many nightsto complete,” saysSimons. This is one ofa handful of novel instruments atCFHT,keeping it on thecutting edge.

Even small telescopes can probe nearby objects likethe Flame Nebula, searchingfor unexplained phenomena. Willgiant telescopes snuff out those searches? (DavidThompson/Caltech)

Another key innovation at the older,smaller telescopes hasbeen automation.At Caltech’s Palomar Observatory, Kulkarnibuilt an enormously productive researchprogram by automating two instruments,the 1.2-meter and 1.5-meter telescopes.The wide-field survey, called the PalomarTransient Factory,has catalogedmillions of supernovas and other short-lived features of the night sky. Thatwas only possible, Kulkarnisays, because of automation,which speeds up theprocess and frees astronomersfrom the mundane tasks of their research. He’sreopening the survey again nextyearas theZwicky Transient Factory, usingthe sametelescopes equipped with updatedcameras.

In fact, as oldertelescopes endure deeper resourcecuts, the only thingthat will save some of them, says Davis,is embracing automation. In 2010,he automated UKIRTso that the wholeoperation could be runfrom the headquarters inHilo, at the base of Mauna Kea. “Aftermaking the changes, our operating budget wentdown to $1.2 million a year,” says Davis.“On larger-aperture telescopes, it’stypically tens of millions.”

Yet, all these advantagesmay notbeenough to save the nation’solder, smaller telescopes. SaysKulkarni, “Either you’re doingastro-particle physics—some big experimentthat costs a lot of money—or you’re goingto build a bigtelescope, like TMT, thatalso costs lots of money. This completely squeezesthe people whousemoderately sized telescopes, peoplethat I call traditionalastronomers.”