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
As NASA prepares to set twin robots loose on the Martian surface and makes plans to send another in 2007, the agency’s long term
As NASA prepares to set twin robots loose on the Martian surface and makes plans to send another in 2007, the agency’s long term
admin
2014-02-20
71
问题
As NASA prepares to set twin robots loose on the Martian surface and makes plans to send another in 2007, the agency’s long term goal is clear: determine whether the red planet does or ever did harbor life.
But the current search for life is necessarily limited to life as we know it, organisms dependent on liquid water. A SPACE, com reader recently suggested that "We as humans are arrogant, simply believing that any other form of life will be just like us. " Researchers devoted to the search for extraterrestrial(ET)have a similar view. "Scientists’ approach to finding life is very Earth-centric," says Kenneth Nealson, a geobiologist at the University of Southern California. "Based on what we know about life on Earth, we set the limits for where we might look on other planets," Nealson said. Within that framework, however, there are extreme cases of life on Earth that suggest the range of places to look on frigid Mars.
Nealson and his colleagues recently found the most extreme sort of organism in a salty liquid lake under the permafrost of Siberia. The organism, named cryopegella, can exist at colder temperatures than any previously discovered. Nealson’s team figures that if the ice at the polar caps of Mars warmed to liquid water, organisms like cryopegella could have awakened and repaired any damage that might have occurred to their various cellular components. That does not mean there are necessarily dormant microbes within the ice caps of Mars. But it does suggest a broader range of potential cradles for life.
Other researchers agree, and a host of so-called "extremophile" discoveries on Earth in recent years indicate the polar regions of Mars might be prime hunting grounds. As on Earth, organisms there might be slathered in natural antifreeze or be able to go dormant for tens of thousands of years, waiting for a brief thaw, their moment in the Sun.
Meanwhile, scientists recognize that there could indeed be life elsewhere in the universe that does not require water. And some astrobiologists are trying to explore the possibilities. But it is a tough problem to approach. In looking for "life as we don’t know it," it’s hard to even imagine what to expect.
Life might or might not exist on Mars. If there are critters there, they might or might not be like bacteria on Earth. In laboratory conditions, scientists in 2001 were able to get one-celled organisms to incorporate an amino acid—a fundamental building block of life—that no other known life uses. The discovery borders on the creation of artificial life, experts said. It also suggests that ET might operate by entirely different rules than those we’re used to.
If life on Mars is fundamentally different from what scientists understand life to be, then current spacecraft and others in the works may well not recognize what’s right under their mechanical noses.
Nealson’s team’s discovery of extreme cases of life on Earth suggests that______.
选项
A、there might be life on Mars that still remains dormant
B、there might be ET in the universe that is like human beings
C、there might be life that is beyond the range of our current search
D、there might be ET elsewhere in the universe that does not require water
答案
C
解析
推断题。文章第四段讲到,纳尔森研究小组在西伯利亚冻土带下的一个盐水湖中发现了最为极端的生物组织,即cryopegella,这种生物体能存活的温度比以前所知道的都要低。他们认为,火星两极的冰帽如果变暖融化,类似cryopegella的生命体就可能复苏,它们各种细胞成分可能受到的损伤也可能修复。这虽然并不意味着火星冰帽中一定会有休眠微生物,但却暗示孕育生命的摇篮可能会更广泛,这也就是说可能超出了我们目前寻找的范围。因此C为正确答案,而A与这句话却相反,B和D都与这个意思不相符合,所以都不对。
转载请注明原文地址:https://kaotiyun.com/show/orXO777K
0
在职攻硕英语联考
相关试题推荐
Thetranslatormusthaveanexcellent,up-to-dateknowledgeofhissourcelanguages,fullfacilityinthehandlingofhistarget
Itwilltakeustwentyminutestogototherailwaystation,______trafficdelays.
Inordertoobtaintheneededinformation,youshouldwritesimply,clearly,andconcisely______thereaderwantstoknow.
Wecannotbe______thechoicesthatourchildrenaregoingtomake,eventhoughwehavecontributedtothosechoices.
Thereisnodenyingthatstudentsshouldlearnsomethingabouthowcomputerswork,justasweexpectthematleasttounderstand
Everynightshelistenedtoherfathergoingaroundthehouse,lockingthedoorsandwindows.Shelistened;thebackdoorclosed
Thesevariedracialgroupshavelearnedtolivetogetherinpeaceand______,settinganexamplewellworthfollowing.
Oldpeoplearealwayssayingthattheyoungpeoplearenot【C1】______theywere.Thesamecommentis【C2】______fromgenerationtog
Theverysoundofournationalanthembeingplayedattheawardingceremonyis______.
TomBrennanwasworkinginaPhiladelphiaofficebuildingwhenhenoticedablackbag.Thebagcontainedabook.Thischance
随机试题
婴幼儿时期最常见的肺炎是(),对于患支原体肺炎的患儿,首选抗生素是()。支气管肺炎患儿抗生素用至体温正常后()d。
患者女性,41岁,既往月经规律,经量中等。末次月经于11天前。今日排便后突然右下腹剧烈痛伴恶心,急诊来院。妇科检查:子宫正常大小,其右侧扪及一手拳大小肿物,触痛明显。对该患者的下一步处理应是
关于正畸疼痛正确的解释是
关于注射用油的质量要求叙述错误的是( )。
证券经纪商可以为投资者提供信息服务,这些服务包括()。
“绣工精巧、针法活泼、图案秀丽、色彩雅洁”,这是()的艺术特色。
一个有效的绩效管理系统的几个环节中,监督属于()环节。
“爱屋及乌”这个成语中涉及的迁移类型是
’Diamonds’,sangMarilynMonroeinthefilmGentlemenPreferBlondes,’areagirl’sbestfriend.’Youmightnotagree,buty
TheWebWaytoLearnaLanguageTheyoungwomanseatednexttousatabarrevealedavaguelyexotic(异国的)air;herlooksand
最新回复
(
0
)