首页
登录
职称英语
【T1】When you are in the business of sending spacecraft to other planets, it
【T1】When you are in the business of sending spacecraft to other planets, it
游客
2025-03-29
26
管理
问题
【T1】
When you are in the business of sending spacecraft to other planets, it is probably wise to do everything you can to keep your space-probes sterile(无菌的).
NASA, America’s space agency, certainly does so. After all, you would not want bugs from one planet to contaminate another where they might possibly thrive.
But according to Curt Mileikowsky, of the Royal Institute of Technology in Stockholm, this may already have happened naturally billions of years ago when the solar system was young. For Dr. Mileikowsky has taken a century-old idea called panspermia(有生源说), and shown that it is plausible.
【T2】
Panspermia is the theory that life does not start independently on each planet that has it(assuming that other planets do). Rather, it hops from place to place, "infecting" new worlds as it goes.
Supported by experts in biology, geology and celestial mechanics, Dr. Mileikowsky argued to the American Astronomical Society meeting in Atlanta that this is not as outlandish as it sounds.
【T3】
Bungling(笨手笨脚的)space organizations apart, the only mode of travel open to microbes seems to be meteorites(流星). Most of these are small bits of junk from the asteroid(小行星)belt that have gone off course.
But some are rocks that have been flung into space from the surfaces of planets as a result of those planets having been struck by even larger bits of rock—decent-sized asteroids or comets.
【T4】
If there is life on such a planet, microscopic forms of it will probably live deep inside rocks, as they do on earth. The acceleration of lift-off would not kill something that size.
【T5】
If a rock is large enough, the heat generated as it is thrown clear will be negligible except at its surface—where, if anything, melting may even produce an airtight skin to protect any microbes deeper down from the unpleasant vacuum of space.
[br] 【T4】
选项
答案
如果这类行星上存在生命的话,微生命形式很可能生活于岩石的深处,正如它们在地球上一样。岩石被抛离的加速度不会毁灭那么小的东西。
解析
转载请注明原文地址:https://www.tihaiku.com/zcyy/4017951.html
相关试题推荐
【T1】Whenyouareinthebusinessofsendingspacecrafttootherplanets,it
【T1】Whenyouareinthebusinessofsendingspacecrafttootherplanets,it
【T1】Whenyouareinthebusinessofsendingspacecrafttootherplanets,it
I’d______hisreputationwithotherfarmersandbusinesspeopleinthecommunity,
BeforehighschoolteacherKimberlyRughgotdowntobusinessatthestarto
BeforehighschoolteacherKimberlyRughgotdowntobusinessatthestarto
BeforehighschoolteacherKimberlyRughgotdowntobusinessatthestarto
______doesbusinesswiththatfellowisboundtolosemoney.A、WhoeverB、WhoC、No
Wemust______onourreputationtoexpandthebusiness.A、improveB、buildC、develo
Therearefourbasictypesofcompetitioninbusinessthatformacontinuum
随机试题
Whatisthemainpurposeofthetalk?[br][originaltext]Goodmorningandwelco
Hehasarrivedlate______A、asusualB、asusuallyC、likeusualD、likeusuallyA本
RobertBrowningisoftenassociatedwith______.A、streamofconsciousnessB、drama
血压降到80mmHg,正常人体通过以下哪些途径使血压回升()A.颈动脉窦压力
A.低钾血症 B.高钙血症 C.低渗性缺水 D.等渗性缺水 E.水中毒下
某公募基金的信息披露文件中,对基金产品的各项风险因素进行分析,并列明与特定基金品
128、当采用常规互感器时,合并单元应____安装。A在保护小室B与互
下列说法中正确的包括()。多选A.羞耻的个体往往会感到沮丧、自卑等,认为自己
下列有关职业怀疑的说法中,错误的是()。A.保持职业怀疑是注册会计师的必备技能
属于全站仪主要组成部分的是( )。A.电子测距仪 B.底座 C.电子经纬仪
最新回复
(
0
)