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Astrophysical andPlanetarySciencesDepartment, University ofColorado, Boulder By Christopher Boozer Globular Clusters debates have continued. have debates these century, after Century ? this nebulaeinside small seeing weonly are own,or thanour other there Are oftheuniverse? part thelargest thenearby Are ofthecosmos? part largest been going onforcenturies. IstheEarth theonly large object in theuniverse? Isthesolar systemthe ours. than bigger bigor as just thatwere galaxies other were thatthere determining for laid thegroundwork calculations thought.These hadoriginally thananyone bigger much really was galaxy andthatour galaxy, ofour outside actually were clusters globular ofthese thatmany determined finally itwas way, In asimilar thedistance. guess can headlight,thenyou car a thatitis you tells Ifsomebody itis. away tellhowfar can’t just you screen, anIMAXmovie headlight, or acar or alitmatch, ifitis don’tknow butyou alightinthedistance, see ought tobeemitting.Ifyou it energy howmuch andknowing ofstar, type aparticular recognizing butinvolve story, another are details The clusters. tothese Earth from thedistances determining for upwithatrick came someone Finally, , making for good viewing of these tightly-packed “galactic suburbs” from Earth. from suburbs” “galactic tightly-packed ofthese goodviewing for making Way, Milky theplaneofthe through move dothey occasionally Only away. oflight-years thousands ofbees, swarm a ofthetime,like halomost outin thegalactic themfar bring ofstars clusters ofthese orbits large The Way. theMilky including galaxies, most halosurrounding spherical ofthe part form They ofstars). millions of hundreds have (which thangalaxies smaller much are clusters Globular pulled apart. aunit,withoutbeing as andmove stable very gravitationally are thatthey cluster globular ina enoughstars are There stragglers. blue called stars andmassive young ofunusually agroup containing acore have gases interstellar of clean fairly are They galaxy. inour stars oftheoldest ofsome ofthousands hundreds and ofthousands balls are clusters Globular NASA M5 Orbits the MilkyWay . Many globular clusters globular . Many G enes EPO is G enes Educ is O ation andPublic u tr eac h http://genes is mis sion.jpl.nas a.gov undistinguished partofalarger debatehas system.Inmanyways,this an just or theuniverse, was galaxy our whether questioned scientists Early owngalaxy. ofour thesize concerning arguments previous mirror clusters globular surrounding arguments Current onthat. depends Everything thedistance?” is “What is, inmodern object particular aboutany fundamentalquestion The mean? information But whatdidallthis astronomers. to thedataavailable increased greatly andphotography) , optics, as (such intechnology advancements frequent century, ofthis theturn After distances. true abouttheir raged arguments academic as ofastronomy, history inthemodern role significant hada have clusters thepuffballofadandelion.These resemble Globular clusters • e-mail: genes e-mail: is epo@mc r e l.or g M15 Globular Cluster Globular M15 are close groups of stars that, from a distance, adistance, that,from ofstars groups close are

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