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學習快評丨qibao666888　　土?(tu)星??(xing)環(huán)?(huan)這??(zhe)個??(ge)“大?(da)圓??(yuan)環(huán)??(huan)”的??(de)直??(zhi)徑??(jing)大??(da)約??(yue)是??(shi)28萬??(wan)公??(gong)里??(li)??，相??(xiang)當??(dang)于??(yu)地??(di)月?(yue)距??(ju)離??(li)的?(de)三??(san)分??(fen)之??(zhi)二??(er)??，但??(dan)是??(shi)土??(tu)星?(xing)環(huán)??(huan)的?(de)平??(ping)均??(jun)垂??(chui)直??(zhi)厚?(hou)度??(du)卻??(que)只??(zhi)有??(you)10米??(mi)左??(zuo)右??(you)??。??所??(suo)以??(yi)說??(shuo)??，土??(tu)星?(xing)的??(de)光??(guang)環(huán)??(huan)“薄??(bo)如??(ru)蟬??(chan)翼?(yi)”??，那??(na)它??(ta)是??(shi)由??(you)什??(shen)么??(me)組??(zu)成?(cheng)的??(de)呢??(ne)？??　　土??(tu)星??(xing)以??(yi)26.7度??(du)的??(de)傾??(qing)角祝(jiao)繞??(rao)太??(tai)陽?(yang)公?(gong)轉(zhuǎn)??(zhuan)??，當??(dang)它??(ta)運?(yun)行??(xing)到??(dao)軌??(gui)道??(dao)特??(te)定??(ding)位??(wei)置??(zhi)時??(shi)??，環(huán)??(huan)平??(ping)面??(mian)恰??(qia)好??(hao)正??(zheng)對??(dui)太??(tai)陽??(yang)??。??此??(ci)時??(shi)??，陽??(yang)光??(guang)以??(yi)不??(bu)足??(zu)1度??(du)的??(de)極??(ji)淺??(qian)角??(jiao)度??(du)掠??(lve)過??(guo)環(huán)??(huan)面??(mian)??，相??(xiang)當??(dang)于??(yu)我??(wo)們??(men)側(cè)??(ce)視??(shi)一??(yi)張??(zhang)A4紙??(zhi)的??(de)邊??(bian)緣??(yuan)??，原??(yuan)本??(ben)璀??(cui)璨??(can)的??(de)光??(guang)環(huán)??(huan)便??(bian)隱??(yin)沒??(mei)在??(zai)黑??(hei)暗??(an)背??(bei)景??(jing)中??(zhong)??。。