芒果视频下载

基本介紹

赤(chi)道(dao)脊是(shi)土(tu)(tu)星(xing)(xing)(xing)(xing)衛(wei)(wei)(wei)星(xing)(xing)(xing)(xing)上存在(zai)的(de)(de)一種(zhong)地(di)(di)貌特征，至今(jin)已在(zai)三(san)顆土(tu)(tu)星(xing)(xing)(xing)(xing)衛(wei)(wei)(wei)星(xing)(xing)(xing)(xing)的(de)(de)發(fa)現了該地(di)(di)貌——即(ji)較大(da)的(de)(de)土(tu)(tu)衛(wei)(wei)(wei)八(ba)和(he)較小的(de)(de)土(tu)(tu)衛(wei)(wei)(wei)十五、土(tu)(tu)衛(wei)(wei)(wei)十八(ba)。三(san)顆衛(wei)(wei)(wei)星(xing)(xing)(xing)(xing)上的(de)(de)赤(chi)道(dao)脊所在(zai)位置(zhi)都接(jie)近(jin)于衛(wei)(wei)(wei)星(xing)(xing)(xing)(xing)赤(chi)道(dao)。這種(zhong)地(di)(di)貌只(zhi)存在(zai)于土(tu)(tu)星(xing)(xing)(xing)(xing)衛(wei)(wei)(wei)星(xing)(xing)(xing)(xing)上，但(dan)還不(bu)確定其形成是(shi)否有共同原因或者只(zhi)是(shi)一種(zhong)巧合。三(san)顆衛(wei)(wei)(wei)星(xing)(xing)(xing)(xing)上的(de)(de)赤(chi)道(dao)脊都是(shi)于2005年為卡西尼號所發(fa)現。

土衛(wei)八(ba)上的(de)(de)(de)赤(chi)道脊的(de)(de)(de)寬(kuan)達(da)20公(gong)(gong)里，高達(da)13公(gong)(gong)里，長度達(da)1300公(gong)(gong)里。土衛(wei)十(shi)(shi)五較之土衛(wei)八(ba)小得(de)多，但是按比例來(lai)說，其上的(de)(de)(de)赤(chi)道脊則更為(wei)顯眼，該地(di)形使(shi)得(de)土衛(wei)十(shi)(shi)五的(de)(de)(de)形狀(zhuang)十(shi)(shi)分(fen)怪(guai)異，看起來(lai)就像(xiang)不明飛(fei)行物。土衛(wei)十(shi)(shi)八(ba)的(de)(de)(de)圖(tu)像(xiang)較為(wei)模糊，但是仍能分(fen)辨出類(lei)似于(yu)土衛(wei)十(shi)(shi)八(ba)的(de)(de)(de)結構。

至今仍不(bu)(bu)清楚這些山(shan)脊(ji)是(shi)如何形(xing)成的(de)(de)(de)，以及三(san)顆(ke)衛(wei)(wei)(wei)星上(shang)的(de)(de)(de)類似地(di)形(xing)是(shi)否存(cun)在著(zhu)某種聯系。由(you)(you)于土(tu)(tu)(tu)衛(wei)(wei)(wei)十(shi)五(wu)和土(tu)(tu)(tu)衛(wei)(wei)(wei)十(shi)八的(de)(de)(de)軌道(dao)(dao)位(wei)(wei)于土(tu)(tu)(tu)星環之內(nei)，因(yin)此(ci)有(you)人認為這兩顆(ke)衛(wei)(wei)(wei)星吸附(fu)了(le)土(tu)(tu)(tu)星環中(zhong)的(de)(de)(de)物質，從而(er)(er)在赤道(dao)(dao)處形(xing)成了(le)這種山(shan)脊(ji)。但(dan)是(shi)這種理論并不(bu)(bu)適用(yong)于土(tu)(tu)(tu)衛(wei)(wei)(wei)八，因(yin)為該(gai)(gai)衛(wei)(wei)(wei)星的(de)(de)(de)軌道(dao)(dao)位(wei)(wei)于土(tu)(tu)(tu)星環之外。曾有(you)科學家(jia)認為土(tu)(tu)(tu)衛(wei)(wei)(wei)八曾經位(wei)(wei)于土(tu)(tu)(tu)星環之內(nei)，從而(er)(er)形(xing)成了(le)該(gai)(gai)地(di)形(xing)，后來由(you)(you)于某種未知原因(yin)而(er)(er)被推出至現今的(de)(de)(de)位(wei)(wei)置。與(yu)之對應，還有(you)一種觀點(dian)認為土(tu)(tu)(tu)衛(wei)(wei)(wei)八的(de)(de)(de)軌道(dao)(dao)位(wei)(wei)置并未發生變化，而(er)(er)是(shi)土(tu)(tu)(tu)星環由(you)(you)于土(tu)(tu)(tu)星的(de)(de)(de)重力場而(er)(er)被拉至更近的(de)(de)(de)軌道(dao)(dao)位(wei)(wei)置。但(dan)是(shi)大(da)多數科學家(jia)都傾向于以下觀點(dian)：土(tu)(tu)(tu)衛(wei)(wei)(wei)八的(de)(de)(de)赤道(dao)(dao)脊(ji)是(shi)由(you)(you)某種內(nei)源性構造活動(dong)形(xing)成的(de)(de)(de)，而(er)(er)與(yu)土(tu)(tu)(tu)衛(wei)(wei)(wei)十(shi)五(wu)和土(tu)(tu)(tu)衛(wei)(wei)(wei)十(shi)八的(de)(de)(de)赤道(dao)(dao)脊(ji)的(de)(de)(de)形(xing)成過程(cheng)沒有(you)聯系。