首页
登录
职称英语
Astronomers have had difficulty accounting for certain planets discovered ou
Astronomers have had difficulty accounting for certain planets discovered ou
游客
2025-02-19
21
管理
问题
Astronomers have had difficulty accounting for certain planets discovered outside our solar system. They are called hot Jupiters because each is similar in mass to Jupiter, the largest solar-system planet, but orbits its parent star at a fraction of the distance at which
Earth
, let alone Jupiter, orbits the Sun. In the standard, solar-system-based theory of planetary formation, such as a massive planet could not form so close to a star. So most attempts to explain a hot Jupiter’s existence envision it forming farther away, then migrating inward. According to one hypothesis, the planet’s gravitational field tugs on the protoplanetary disk of dust and gas from which it formed. The disk exerts its own gravitational tug, and this interplay of forces robs the planet of momentum in its orbital path, forcing it to spiral in toward the star. According to another hypothesis, the planet’s gravitational field is so strong that it creates a groove in the disk, partitioning it into inner and outer regions; the resulting gravitational interactions between the planet and these regions cause the planet to lose orbital momentum and spiral inward. Another question remains: what prevents the planet from continuing its spiral until it collides with the star? [br] Which of the following elements is part of one but not both of the hypotheses discussed in the passage?
选项
A、an interplay of gravitational forces
B、a loss of orbital momentum
C、a protoplanetary disk composed of dust and gas
D、a protoplanetary disk divided into two regions.
E、The movement direction of hot Jupiters
答案
D
解析
这道题目相当于问两个假说之间的区别。D项是假说二特有的。A、B、C、E这四项都是共同点。
转载请注明原文地址:https://tihaiku.com/zcyy/3964064.html
相关试题推荐
Astronomershavehaddifficultyaccountingforcertainplanetsdiscoveredou
CertainpracticescommonintheearlyUnitedStatesmakeiteasyforhistori
Onewaytodeterminewhichplanetsoutsidethesolarsystemmightharborlif
Onewaytodeterminewhichplanetsoutsidethesolarsystemmightharborlif
MarinearchaeologistsrecentlydiscoveredunderwaterinanancientMediterra
Whatmighttheinfluencesbe? Certainlytherecouldbesomeinfluencesbrought
Itisgenerallybelievedthatsomepeoplearebornwithcertaintalents,for
TheBrainsBusinessAForthoseofacertainageandedu
TheBrainsBusinessAForthoseofacertainageandedu
TheBrainsBusinessAForthoseofacertainageandedu
随机试题
Itwas3:45inthemorningwhenthevotewasfinallytaken.Aftersixmonths
Itcanbeinferredthatthedeafboy’slifeintheorphanagewas[br]Itcanbe
关于集气管,下列说法不正确的是()。A.集气管是汇集从各炭化室导出的粗煤气
关于饮片的供应,下列说法不正确的是A.保管 B.消毒 C.查斗 D.调剂
沟通、领导和磋商是属于()的技能。A.项目管理 B.一般管理 C
A.嵌顿性疝 B.难复性疝 C.绞窄性疝 D.可复性疝 E.滑动性疝疝块
根据《金融机构反洗钱规定》,国务院反洗钱行政主管部门是()。A.商务部 B.
项目法人应自工程开工之日起()个工作日内,制定法人验收工作计划,报法人验收监督管
我国证券公司的设立采取()。A:报备制B:审批制C:备案制D:注册制
下列关于重整计划草案的表决分组,表述错误的有()。A.拖欠的划入社会统筹账
最新回复
(
0
)