Unit4Astronomy:thescienceofthestars备课资源Section1:AtextstructureanalysisofHOWLIFEBEGANONTHEEARTH1.TypeofwritingandsummaryofthetextTypeofwritingThisisadescriptivewriting.MainideaofthepassageTheearthcameintobeingafterthe“BigBang”.Thensmallplantscamegrowinginthewater,followedbygreenplantsappearingonland.Intheendappearedsmallcleveranimals.Topicsentenceof1stparagraphAfterthe“BigBang”,theearthwasjustacloudofenergeticdust.Topicsentenceof2ndparagraphTheearthwasdifferentbecauseofthearrivalofsmallplantsgrowinginthewater.Topicsentenceof3rdparagraphManymillionsofyearslaterthefirstgreenplantsbegantoappearonland.Topicsentenceof4thparagraphSmallcleveranimalsappearedandspreadallovertheearth.2.AtreediagramSection2:BackgroundinformationforUnit4Astronomy:thescienceofthestars1.THEPLANETS行星AlthoughweliveinaverysmallpieceoftheUniverse,it'sstillwherewecallhomeandit'saveryinterestingplace.Thenineplanetsthatmakeupoursolarsystemrangefromverytinyrockyplanetstohugegasgiantsfeaturingfascinatingringsystems.Mercury水星MercuryistheclosestplanettotheSun.Itssurfacehasmanythousandsofimpactcratersasaresultofbeingbombardedbyobjectssincethesolarsystem'searlydays.SinceMercuryhasnoprotectiveatmosphere,thetemperatureonthesurfacerangesfromextremelyhotonthesidefacingtheSuntoextremelycoldonthesidethatfacesawayfromtheSun.用心爱心专心116号编辑Afterthe“BigBang”,theearthbeingjustacloudofenergeticdust.thearrivalofsmallplantswinginthewatergreenplantsbeginningtoappearonlandSmallcleveranimalsappearingandspreadingallovertheearth.Venus金星（太白星）VenusisnamedaftertheRomangoddessofloveandbeauty.Thisisoneofthosecaseswherebeautyisonlyskindeep,though,asthesurfaceofVenusisaveryunpleasantplacefeaturingveryhightemperatures,windsthatblowhundredsofmilesperhourandanatmosphereofsulfuricacid.Venusisanexampleofrunawaygreenhouseeffectonaplanetaryscale.Earth地球Peoplealwayssaythere'snoplacelikehome.Ourhomeplanetisaverybeautifulplacewiththemostvariedsurfaceintheentiresolarsystem.Fromadistance,ourplanetlookslikeabeautifulbigbluemarble.Mars火星TheRedPlanetisnamedaftertheRomangodofwar.It'sdistinctiverustcoloriseasilyseenthroughasmalltelescope.ThesurfaceofMarsfeaturesmanymountains,canyonsandevenpolaricecapsthatlookalotlikethosehereonEarth.Inancienttimes,Marsmayhaveharboredsomekindoflife,andthereisalotofresearchgoingonnowtryingtogetadefinitiveanswerastowhetherwearetheonlylifeformsinthesolarsystem.Jupiter木星Jupiteristhelargestplanetinoursolarsystem.Ithasatleastsixty-onemoonsandfeaturestheGreatRedSpot,whichisahuge"storm"thathasbeenobservedfromhereonEarthforoverthreehundredyears.Saturn土星Saturnisoneofthemostbeautifulplanetsinthesolarsystem.It'sfascinatingsystemofringshavebeenasourceofwondersincewefirstsawthemwiththeearliesttelescopes.Althoughtheringslookfairlysimplethroughasmalltelescope,spacecraftpictureshaverevealedthatwhatlooksliketworingsthroughatelescopeisactuallyhundredsofindividualringsystems.Inaddition,Saturnhassomanymoonsthatitislikeaminiaturesolarsystem.Uranus天王星Uranusisoneofthegiantgasplanetsinthesolarsystem.Itsmysteriousblue-greencolorprovidesveryfewcluesastowhatisgoingonunderneaththesurfaceclouds.Uranusalsohasaveryfaintringsystemthatwedidn'tknowexisteduntiltheplanetwasvisitedbytheVoyagerspacecraft.Neptune海王星NeptunewasthelaststoptheVoyagermissionmadebeforeifleftoursolarsystem.WhatwefoundoutfromVoyagerwasthatNeptunehaswindsthatblowhundredsofmilesperhourandamoonthatfeatures"geysers"ofnitrogenthateruptandleavedarkmarksonthesurface.Pluto冥王星Plutoisthesmallestandmostmysteriousplanetinoursolarsystem.PlutoissofarawaythattheSunisjustadimpointoflightthatlooksalotlikeanyotherstar.Plutohasonemoon,Charon,thatisalmostasbigastheplanetitself.2.TheBigBangTheory大爆炸理论TheBigBangTheoryisthedominantscientifictheoryabouttheoriginoftheuniverse.Accordingtothebigbang,theuniversewascreatedsometimebetween10billionand20billionyearsagofromacosmicexplosionthathurledmatterandinalldirections.用心爱心专心116号编辑In1927,theBelgianpriestGeorgesLemairewasthefirsttoproposethattheuniversebeganwiththeexplosionofaprimevalatom.Hisproposalcameafterobservingtheredshiftindistantnebulasbyastronomerstoamodeloftheuniversebasedonrelativity.Yearslater,EdwinHubblefoundexperimentalevidencetohelpjustifyLemaire'stheory.Hefoundthatdistantgalaxiesineverydirectionaregoingawayfromuswithspeedsproportionaltotheirdistance.Thebigbangwasinitiallysuggestedbecauseitexplainswhydistantgalaxiesaretravelingawayfromusatgreatspeeds.Thetheoryalsopredictstheexistenceofcosmicbackgroundradiation(theglowleftoverfromtheexplosionitself).TheBigBangTheoryreceiveditsstrongestconfirmationwhenthisradiationwasdiscoveredin1964byArnoPenziasandRobertWilson,wholaterwontheNobelPrizeforthisdiscovery.AlthoughtheBigBangTheoryiswidelyaccepted,itprobablywillneverbeproved;consequentially,leavinganumberoftough,unansweredquestions.用心爱心专心116号编辑
