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 discovery of planets around distant stars has become like space-shuttle launches newsworthy but just barely. With some 50 ex
The discovery of planets around distant stars has become like space-shuttle launches newsworthy but just barely. With some 50 ex
admin
2010-04-30
52
问题
The discovery of planets around distant stars has become like space-shuttle launches newsworthy but just barely. With some 50 extra-solar planets under their belt, astronomers have to announce something really strange to get anyone’s attention.
Last week they did just that. Standing in front of colleagues and reporters at the American Astronomical Society’s semiannual meeting in San Diego, the world’s premier planet-hunting team astronomer Geoffrey Marcy of the University of California, Berkeley, and his colleagues, presented not one but two remarkable finds. The first is a pair of planets, each about the mass of Jupiter (木星), that whirl around their home star 15 light-years from Earth in perfect lockstep. One takes 30 days to complete an orbit, the other exactly twice as long. Nobody has ever seen such a configuration. But the second discovery is far stranger a solar system 123 light-years away, in the constellation Serpens (巨蛇座), that harbors one "ordinary" planet and another so huge 17 times as massive as Jupiter that nobody can quite figure out what it can be. "It is," says Marcy, "a bit frightening." What’s frightening is that these discoveries make it clear how little astronomers know about planets, and they add to the dawning realization that our solar system and by implication Planet Earth may be a cosmic oddball. For years theorists figured that other stars would have planets more or less like the ones going around the sun. But starting with the 1995 discovery of the first extra-solar planet a gassy monster like Jupiter but orbiting seven times as close to its star as Mercury (水星) orbits around our sun each new find has seemed stranger than the last. Searchers have found more "hot Jupiters" like that first discovery. These include huge planets that career around their stars not in circular orbits but in elongated ones; their gravity would send any Earthlike neighbors flying off into space. Says Princeton astronomer Scott Tremaine: "Not a single prediction for what we’d find in other systems has mined out to be correct."
Last week’s giant was the most unexpected discovery yet. Conventional theory suggests that it must have formed like a star, from a collapsing cloud of interstellar gas. Its smaller companion, only seven times Jupiter’s mass, is almost certainly a planet, formed by the buildup of gas and dust left over from a star’s formation. Yet the fact that these two orbs are so close together suggests to some theorists that they must have formed together so maybe the bigger one is a planet after all. Or maybe astronomers will have to rethink their definition of "planet". Just because we put heavenly objects into categories doesn’t mean the distinctions are necessarily valid, as Tremaine puts it, "When your classification schemes start breaking down, you know you’re learning something exciting. This is wonderful stuff."
The finds of Geoffrey Marcy are frightening in that______.
选项
A、it’s the first time that astronomers have discovered such space entity
B、it substantially implies some kind of subversion to our present realization
C、it is an entire negation of the present astronomic research
D、they discovered the first extra-solar planet in astronomic study
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/4kOK777K
0
大学英语六级
相关试题推荐
Diamonds’pricedependsalmostentirelyontheirscarcity_______________________(既然钻石没有什么内在价值).
Thescientificestablishmentisplayingakeyroleinresearchanddevelopmentofgeneticengineeringbiotechnologyandinactiv
Thepolicemetdifficultiesatthebeginningofthecasethat______.Neilwasstuckinfinancialproblemsbecause______.
Thefirsttwostagesinthedevelopmentofcivilizedmanwereprobablytheinventionofprimitiveweaponsandthediscoveryoff
A、Itisconsideredtobepartofthesecondaryeducation.B、Itisgiventoanyonewantingtogetadriver’slicense.C、Itiscar
ProfessorBhattandRobMeakinhavedevelopedamethodto______.Accordingtothepassage,whatdoyouknowaboute-businessi
A、Hethoughtthathewouldeitherfindagoodjoborhewouldbeathief.B、Hesaidthathewouldbecomerichbywayofrobbing
A、Hemanagedthesalesdepartment.B、HegaveseminarsontheInternet.C、Heworkedasacustodian.D、Hedesignedsoftware.CWhat
A、Themanshouldstartrunningdaily.B、Shealsopreferstoexerciseintheafternoon.C、It’simportanttowarmupbeforeexerci
I’msurealmosteveryoneofyoulookedatyourwatchorataclockbeforeyoucametoclasstoday.Watchesand【B1】______seema
随机试题
ManyvisitorsfindthefastpaceatwhichAmericanpeoplemoveverythroubling.One’sfirstimpressionislikelytobethatever
在两个神经元之间传递信息的特化结构称为
A.敌敌畏B.灭鼠药C.氰化物D.敌百虫E.巴比妥类可饮用3%过氧化氢溶液后引吐的毒物是
A.牙结构异常B.牙形态异常C.牙数目异常D.牙萌出异常E.牙结构形态均异常牙釉质发育不全症属于
( )按照国务院规定的职责,组织稽查特派员,对国家出资的重大建设项目实施监督检查。
国内生产总值的三种表现形态包括价值形态、收入形态和()。
Inthiscase,wewerecompelledtocancelthecontract,ratherthanlodgingapenaltyagainstyou.
邓小平同志1950年9月在对全国经济保卫工作会议的指示中说:“保卫工作必须特别强调党的领导作用,并在实际上受党委直接领导,否则是危险的。”()
片上系统(SOC)也称为系统级芯片。下面关于SoC叙述中,错误的是()。
A、Onceaweek.B、Twiceaweek.C、Onceamonth.D、Twiceamonth.C信息明示题。短文开头指出Mathewwenttohimonceamonth。故选C。
最新回复
(
0
)