全优课堂英语必修第三册(人教版)课件UNIT 4.pptx

UNIT4SPACEEXPLORATION;美文导入;素养解读：本单元隶属于“人与自然”主题语境下的“宇宙探索”主题群。通过本单元的学习，学生应了解人类不断探索太空的历史，熟知太空探索史上具有划时代意义的重大历史事件，并学习从事太空探索的科学家及航天英雄们在探索太空奥秘过程中不畏艰难、勇于奋斗、甘于奉献的精神，从而增强探索精神和谋求人类和平与发展的意识。;主题：太空探索

学科素养：人与自然

难度系数：★★★

;WhenastronautslandonMars,acoupleofdecadesfromnow,perhaps,they’llneedtofindawaytocommunicatewitheachother,withequipmentonandaroundtheplanet,andwithmissioncontrolbackonEarth.

ButsettingupaWi-FiconnectiontoEarth’sInternetwon’tbeachoice.Earthissimplytoofaraway—around55millionto400millionkilometres,dependingonwheretheplanetsareintheirorbits.Wewillneedanotherstrategy.;EstablishinggoodcommunicationequipmentisessentialforhumanmissionstoMars.Researchersaretestingwaystoupgradeexistingnetworks.Forexample,NASA’sPsychemission,whichliftedoffinOctoberwiththejobofexploringanasteroid(小行星)betweenMarsandJupiter,willalsotestthecommunicationusinglasers.Laserscouldcarryfarmoredatathantheradiowavesthathavebeenusedfromtheearliestdaysofspacetravel.;

ThereisnostrategywhichcangetridofthetimelagincommunicationsbetweenEarthandMars;amessagemovingatthespeedoflighttakesanywherebetween4and24minutesforaone-waytrip.Inotherwords,aquickpingtomissioncontrolisoutofthequestion,nottomentionanInternetcallhome.

;There’salsotheissueofsolarconjunction(聚合),saysParfitt,whenthesuncomesbetweenEarthandMars.Thishappensforacoupleofweekseverytwoyearsorso,cuttingoffcommunicationsbetweentheplanets.ThelastonetookplaceinNovember.

ButnewapproachescouldopenpossibilitiesthatmakecommunicationsonMarsmorelikewhatweexperiencehereonEarth.Atleastoneresearchteamhaswondered:WhatifMarshaditsownInternet?;strategy/?str?t?d?i/n.策略

essential/??sen?l/adj.必不可少的；非常重要的

upgrade/??p?ɡre?d/vt.升级；改善

issue/???u?/n.问题

approach/??pr??t?/n.方法;co