【文档说明】必修3背景资料：Unit4Astronomy拓展阅读Alightshowinthesky.docx，共(2)页，16.416 KB，由envi的店铺上传

转载请保留链接：https://www.doc5u.com/view-372f82c9beae5bdbeb24d1f133c8429d.html

以下为本文档部分文字说明：

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,Africaa

ndwesternAsiasawarare,beautifuleclipse(月食)onthenightofSept27orearlymorningofSept28lastyear.Theeventlast

edaboutanhour.Here'swhatyouneedtoknowabouttheevent.Whatisasupermooneclipse?Asupermoonhappenswhenafullmoonreachestheclosestp

ointtoEarthinitsorbit(轨道).Theorbitisnotaperfectcircle,soonepointisclosest.Atthispoint,themoonisonly225,000milesfromEart

h.That'swhatmakesthemoonlookabout14%largerand30%brighterinthesky.Afulllunareclipseoccurswhenthesun,Ear

th,andmoonlineup,withEarthdirectlybetweenthemoonandthesun.Themoon,completelyinEarth'sshadow(阴影),takesonareddishcolor.Asupermoon

eclipseiswhathappenswhenthesetwoeventsoccuratthesametime.Howfrequentlydoesasupermooneclipseoccur?Supermoonsorlunareclips

esbythemselvesarenotrare.Butthetwooccurtogetherveryinfrequently.Since1900,asupermooneclipsehasonlyhappenedfiveothertimes—1910,1928,1946,19

64,and1982.Thenextonewillhappenin2033.Whydidthemoonlookreddish?Lightwasscattered(分散)throughEarth'satmosphere.Onlylightthatpass

edthroughouratmospherereachedthemoon.Sincetheplanet'sgaseousblankettrapsbluelight,itonlyreflects(反射)themorereddishlightontothemoon.Thatcolorcancha

ngebasedonhowmuchdustisinEarth'satmosphereduringtheeclipse.ThereddishcolorhasearnedlunareclipsesthenicknameBloodMoon.“You'rebasically

seeingallofthesunrisesandsunsetsacrosstheworld,allatonce,beingreflectedoffthesurfaceofthemoon,”NASAscientistDr.SarahNoble

said.