现代科技概论-天文学2

科学、技术与社会系列课程现代科学技术概论：天文篇AnIntroductiontoModernScienceandTechnology：astronomy概述：太阳系主要天体TheterrestrialplanetsMercury,Venus,Earth,andMars,anddwarfplanetCeres.SizestoscaleThefourgasgiantsagainsttheSun:Jupiter,Saturn,Uranus,Neptune(Sizestoscale,distancesnottoscale)MESSENGERfalse-colorimageofMercuryViewofMercuryfromMariner10Firsthigh-resolutionimageofMercurytransmittedbyMESSENGER(falsecolor)Venusinrealcolor.Thesurfaceisobscuredbyathickblanketofclouds.CloudstructureintheVenusianatmospherein1979,revealedbyultravioletobservationsbyPioneerVenusOrbiterVenusisalwaysbrighterthanthebrighteststarsMarsin1980asseenbytheViking1orbiterMartiantripodillustrationfromthe1906FrencheditionofTheWaroftheWorldsbyH.G.Wells.Martiangeologicalfeatures,suchastheFaceonMars,sometimestriggerfacialpareidoliaSmallpartoftheCydoniaregion,takenbytheViking1orbiterandreleasedbyNASA/JPLonJuly25,1976.MarsReconnaissanceOrbiterimagebyitsHiRISEcameraoftheFaceonMars”VikingOrbiterimageinsetinbottomrightcornerFirstpanoramicviewbyViking1fromthesurfaceofMars.1975MarsPathfinder,SojournerroveronMarsonsol22.1997MarsPathfinderpanoramaoflandingsitetakenbyIMPNASA'sMarsExplorationRoverMission-A,Spirit,2004PartofapanoramatakenbytheSpiritroverin2004Martiansunsetin2005bySpiritRealimageofEagleCrater,Opportunitylander,andwheeltracks,asseenbyMER-BOpportunityin2004fromplanetMarsImagetakenbythepanoramiccameraaboardOpportunityshowingtherover'semptylander,ThiscolorviewofamineralveincalledHomestakecomesfromOpportunity'spanoramiccamera.OpportunityexamineditinNovember2011andfoundittoberichincalciumandsulfur,possiblythecalcium-sulfatemineralgypsumChineseMars-explorationspaceprobe,Yinghuo-1,11,2011TheMarsScienceLaboratory,Curiosityrover.TheMSLwaslaunchedNovember26,2011,andisscheduledtolandonMarsAugust6and20,2012类木行星（Jovianplanet,气体巨行星GasGiant）TheSolarSystem'sfourgasgiantsagainsttheSun,toscaleAcompositeCassini-HuygensimageofJupiterApproximatesizecomparisonofEarthandJupiterSaturnimagedbytheCassiniorbiterAroughcomparisonofthesizesofSaturnandEarth.SaturnstormcirclesplanetUranuspresentedanearlyfeaturelessdisktoVoyager2SizecomparisonofEarthandUranusNeptunefromVoyager2withGreatDarkSpotatleftAsizecomparisonofNeptuneandEarthComputer-generatedmapofPlutofromHubbleimages,synthesisedtruecolourandamongthehighestresolutionspossiblewithcurrenttechnologyPluto'svolumeisabout0.6%thatofEarth1.Core2.Radiativezone3.Convectivezone4.Photosphere5.Chromosphere6.Corona7.Sunspot8.Granules9.ProminenceAnillustrationofthestructureofthesunDuringatotalsolareclipse,thesolarcoronacanbeseenwiththenakedeye,duringthebriefperiodoftotality.TakenbyHinode'sSolarOpticalTelescopeonJanuary12,2007,thisimageoftheSunrevealsthefilamentarynatureoftheplasmaconnectingregionsofdifferentmagneticpolarity.LimbFlareAstar-formingregionintheLargeMagellanicCloud.NASA/ESAimageArtist'sdepictionofthelifecycleofaSun-likestarAcomparisonbetweenthewhitedwarfIKPegasiB(center),itsA-classcompanionIKPegasiA(left)andtheSun(right).Thiswhitedwarfhasasurfacetemperatureof35,500K.Anartist'sconceptionofastarquake,orstellarquake.Simulatedviewofablackhole(center)infrontoftheLargeMagellanicCloud.Notethegravitationallensingeffect,whichproducestwoenlargedbuthighlydistortedviewsoftheCloud.Acrossthetop,theMilkyWaydiskappearsdistortedintoanarc.Simulationofgravitationallensingbyablackhole,whichdistortstheimageofagalaxyinthebackground(largeranimation)MilkyWaygalaxy,ImageofthenightskyaboveParanalAccordingtotheBigBangmodel,theUniverseexpandedfromanextremelydenseandhotstateandcontinuestoexpandtoday.Acommonanalogyexplainsthatspaceitselfisexpanding,carryinggalaxieswithit,likespotsonaninflatingballoon.Thegraphicschemeaboveisanartist'sconceptillustratingtheexpansionofaportionofaflatuniverse.Thisisanartist'sconceptoftheUniverseexpansion,wherespace(includinghypotheticalnon-observableportionsoftheUniverse)isrepresentedateachtimebythecircularsections.Noteontheleftthedramaticexpansion(nottoscale)occurringintheinflationaryepoch,andatthecentertheexpansionacceleration.TheschemeisdecoratedwithWMAPimagesontheleftandwiththerepresentationofstarsattheappropriatelevelofdevelopment.Theasteroidbelt(showninwhite)islocatedbetweentheorbitsofMarsandJupiter.较大的小行星大致是球形，而多数小行星形状不规则。GraspaIdaandDactylMathildeEros研究小行星的意义•准确测定天文单位。•测定行星的质量：当小行星接近大行星时，大行星对它的摄动作用必然影响它的轨道，从它轨道的微小变化中即可计算出行星的实际质量。•对天体测量的作用。利用小行星的轨道根数求得黄道和天赤道的准确位置。•为研究太阳系起源和演化提供线索。小行星有可能是残存的大小“星子”，因此保留了许多太阳系形成初期的状态，被天文学家称为太阳系早期的“活化石”。•在人类进入航天飞机时代后，小行星可能成为太空探测的重要基地和廉价的中继站。CometHale–Bopp,asseenon29March1997inPazin,Croatia哈雷1656~1742Halley'sCometonMarch8,1986•最早记录：公元前1057年（周武王伐纣之年）•西方最早记录：1682年•回归周期：76年•上次回归：1986年•下次回归：2061年AnimageofAmeteorshowerinJoshuaTreeNationalPark,CaliforniaAug.11,2007EtaAquaridsmeteorshower