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Alightshowinthesky语篇导读：2015年9月27日至28日上演的月全食是一次超级月亮和红月的完美结合，你知道这是怎么形成的吗？PeopleintheUnitedStates,Europe,Afric

aandwesternAsiasawarare,beautifuleclipse(月食)onthenightofSept27orearlymorningofSept28lastyear.Theeventl

astedaboutanhour.Here'swhatyouneedtoknowabouttheevent.Whatisasupermooneclipse?Asupermoonhappenswhenafullmo

onreachestheclosestpointtoEarthinitsorbit(轨道).Theorbitisnotaperfectcircle,soonepointisclosest.Atthispoint,themoonisonly225,000milesfromEarth.Tha

t'swhatmakesthemoonlookabout14%largerand30%brighterinthesky.Afulllunareclipseoccurswhenthesun,Earth,andmoonlineup

,withEarthdirectlybetweenthemoonandthesun.Themoon,completelyinEarth'sshadow(阴影),takesonareddishcolor.As

upermooneclipseiswhathappenswhenthesetwoeventsoccuratthesametime.Howfrequentlydoesasupermooneclipseocc

ur?Supermoonsorlunareclipsesbythemselvesarenotrare.Butthetwooccurtogetherveryinfrequently.Since1900,asupermooneclipsehas

onlyhappenedfiveothertimes—1910,1928,1946,1964,and1982.Thenextonewillhappenin2033.Whydidthemoonlookreddish?Lightwasscattered(分散)throughEarth's

atmosphere.Onlylightthatpassedthroughouratmospherereachedthemoon.Sincetheplanet'sgaseousblankettrapsbluelight,itonlyreflects(反射)themorereddishlighton

tothemoon.ThatcolorcanchangebasedonhowmuchdustisinEarth'satmosphereduringtheeclipse.ThereddishcolorhasearnedlunareclipsesthenicknameBloodMo

on.“You'rebasicallyseeingallofthesunrisesandsunsetsacrosstheworld,allatonce,beingreflectedoffthesurfaceofthemoon,”NASAscient

istDr.SarahNoblesaid.