首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The search for water—and possible life—on Mars got a boost this week as scientists announced evidence of an ancient ocean on the
The search for water—and possible life—on Mars got a boost this week as scientists announced evidence of an ancient ocean on the
admin
2018-06-06
48
问题
The search for water—and possible life—on Mars got a boost this week as scientists announced evidence of an ancient ocean on the planet’s northern plains.
The massive, sediment-filled basin surrounded by "shoreline-like" features was first spotted when scientists were mapping Mars’s surface using images from the late-1970s Viking missions.
The features made theories of an ancient Martian ocean quite popular—until NASA’s Mars Global Surveyor highlighted some seemingly insurmountable problems. The Arabia and Deuteronilus "shorelines" are thousands of kilometers long. But they undulate like a long wave, rising and falling in height as much as several kilometers(more than a mile)along their length. "That doesn’t seem to jibe with the idea that they are shorelines, because shorelines form at sea level," said lead author Taylor Perron, a postdoctoral fellow in Harvard University’s Department of Earth and Planetary Sciences.
But there really was an ocean there, Perron and colleagues now suggest in a finding that adds to a number of recent studies bolstering evidence of Mars’s watery past. The researchers believe that Mars’s poles, along with the axis the planet spins on, have moved about 1,850 miles(3,000 kilometers)during the past two or three billion years. The process, known as "true polar wander", can cause dramatic topographic changes in a planet’s surface—in this case making the once-flat shorelines rise and fall over enormous distances. "When the spin axis moves relative to the surface, the surface deforms, and that is recorded in the shoreline," said co-author Michael Manga, professor of earth and planetary science at the University of California, Berkeley.
On the Martian equator one finds the Tharsis rise—a massive bulge that holds the colossal volcano Olympus Mons. "The largest mountain in the solar system is sitting almost right on the equator, and that’s right where you should expect such a large surface load to be," Perron said. "That tells you that if Mars experienced any true polar wander after the creation of Tharsis, it should reorient in such a way that keeps Tharsis at the equator—a circle 90 degrees from Tharsis."
The current locations of the poles, along with calculations of their previous positions based on the deformation of the shorelines, suggest just such an alignment.
The findings are sure to spark debate among many professionals in search of a liquid "smoking gun" on the red planet. Jeff Moore, a planetary geologist at NASA’s Ames Research Center who is unaffiliated with the study, finds it plausible that early Mars had large standing bodies of water—either liquid or frozen. "But while the new study presents a possible explanation for why the shorelines don’t follow a constant contour, it’s not a conclusive one," Moore said.
It can be inferred from Tharsis research EXCEPT that______.
选项
A、a massive bulge holds the colossal volcano Olympus Mons
B、whether Mars experienced any true polar wander depends on the movement of Tharsis
C、the result shows that Tharsis has moved a circle 90 degrees from its original position
D、tharsis was originally located at the equator
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/ooSO777K
本试题收录于:
NAETI中级口译笔试题库外语翻译证书(NAETI)分类
0
NAETI中级口译笔试
外语翻译证书(NAETI)
相关试题推荐
Thirtyyearsago,whenChristianBoerwasfirstlearninghowtoreadwhilegrowingupintheNetherlands,hemadealotofmista
Thereissomethingintrinsicallyfascinatingabouttheideaofevolution.Whatprinciplesgoverntheevolutionofaspecies?And
Menandwomenshouldlimittheiralcohol______tolessthanabottleandahalfofwinethreedaysaweektominimizehealthrisk
Ifthereisanyendeavorwhosefruitsshouldbefreelyavailable,thatendeavorissurelypubliclyfinancedscience.Morally,ta
Thenonverbal______communicatedinbusinessinteractionsthroughfacialexpressionsandthemovementsofarms,legsandhandsar
Thewomanwoulddieifthechilddied.Thewomanwouldbeliedownwithabrokenheart.
InternetMarketingisfittinginwiththenewchangesofconsumingideasfortheregressionof______consumptionneeds.
DeclanMayes,PresidentoftheMusicBuyersAssociation,isfuriousatarecentannouncementbytherecordingindustryregarding
Acasualemployeeisonewhoisengagedandpaidbyagreementbetweentheemployerandtheemployee.There’sathree-hourminimu
悉尼(Sydney)是个非常现代化的城市,但也有许多历史名胜古迹。在市中心,你依然可以看到一些很久以前就建造在那里的老房子。
随机试题
职业生涯规划由下列()几个环节组成。
(2007年)盈亏平衡分析是一种特殊形式的临界点分析,它适用于财务评价,其计算应按项目投产后以下哪项计算?()
对人口及人均收入的调查分析属于一般投资机会研究的()投资机会研究。
追究刑事责任的执法主体是法定的司法机关,即()。
建筑安装工程费用的规费中,社会保险费包括()。
自我评估法评估商业银行面临的操作风险主要从()两个角度来评估风险的大小。
甲厂向乙厂发出信函,表示愿以1万元出让设备一台。乙厂回复:愿意购买该设备,但价格应为8000元;甲厂又回函:价格可为9000元,复函即供货。乙厂经办人因工作不负责任,收到甲厂的回函后,未予处理。后甲厂将设备发送到乙厂,乙厂才发现对甲厂原函未处理,下列选
要安装IIS、添加可选组件或删除可选组件,请写出操作步骤。请写出配置基本Web站点的步骤。
NEWYORK—ThepeopleatUNICEF’s(联合国国际儿童教育基金会的)OperationCenterhavebeenworkingaroundtheclocktoarrangethereliefefforts
Peopleinsunny,outdoorsystates—Louisiana,Hawaii,Florida—saytheyarethehappiestAmericans,andresearchersthinktheykno
最新回复
(
0
)