首页
登录
职称英语
In its first month orbiting Saturn, the Cassini spacecraft has detected a ne
In its first month orbiting Saturn, the Cassini spacecraft has detected a ne
游客
2023-10-22
9
管理
问题
In its first month orbiting Saturn, the Cassini spacecraft has detected a new radiation belt in an unexpected place, its invisible swarm of trapped high-energy particles circling the planet inside the inner edge of Saturn’s signature disk of luminous rings.
Scientists who reported the discovery said yesterday that they were surprised to find a relatively small radiation belt completely isolated from a planet’s main radiation belts, which lie at much greater distances. They had not expected that such a concentration of energetic particles could be sustained inside the famous Saturnian rings.
The phenomenon of a single isolated belt, the scientists said, has never been observed at any other planet in the solar system. By contrast, the Van Allen belts of Earth consist of two related regions of intense radiation trapped by the planet’s magnetic field.
In a NASA conference call with reporters, Dr. Donald G. Mitchell, a Cassini mission scientist from Johns Hopkins University, said the newly discovered radiation belt was detected as the spacecraft made its closest approach to Saturn immediately after rocketing into its orbit on July 1. No previous spacecraft visiting Saturn had been in the proper position to make such a discovery.
Dr. Mitchell said it was the spacecraft’s imaging magnetometer that had observed the radiation belt, which extended around Saturn from about 15,000 miles above the planet’s cloud tops to the inner edge of the innermost of its spectacular rings. The belt is much smaller, and the energies of its particles are less intense, than Saturn’s main radiation belts.
With its discovery, Dr. Mitchell said, "we have seen something that we did not expect: that radiation belt particles can hop over obstructions like Saturn’s rings."
Other Cassini mission scientists reported puzzling patterns of lightning and thunderstorms on Saturn and observations of a striking glow emanating day and night from the planet’s largest moon, Titan. [br] In the last paragraph, "emanating"could be replaced by_______.
选项
A、changing
B、emitting
C、disappearing
D、transporting
答案
B
解析
考点单词emanating前的glow(红光)和后的from…应该表明科学家发现了有红光从土星的卫星Titan不断地“发出”,故本题答案应为B。其他选项的词义放到原文中都说不通。
转载请注明原文地址:https://tihaiku.com/zcyy/3121598.html
相关试题推荐
Ifallgoesaccordingtoplan,twospacecraftwill______;closeencounterswith
Thermalexpansionofsolidis______detectedbyournakedeyes.A、smallsoasno
Thermalexpansionofsolidis________detectedbyournakedeyes.A、smallsoas
InitsfirstmonthorbitingSaturn,theCassinispacecrafthasdetectedane
InitsfirstmonthorbitingSaturn,theCassinispacecrafthasdetectedane
InitsfirstmonthorbitingSaturn,theCassinispacecrafthasdetectedane
随机试题
He(success)______inwritingabookwiththehelpofhisfatherlastyear.succeed
一般工程质量缺陷是指对结构构件的受力性能或安装使用性能无决定性影响的缺陷。
C
电子商务系统所涉及的四种“流”中,是最基本的、必不可少的。A.资金流 B.信
用人情做出来的朋友只是暂时的,用人格吸引来的朋友才是______的。所以,丰富自
判别滑坡的标志包括()。A.岩土结构方面的标志,如岩土体扰动松脱现象、产状不
下列土地,可以依法免缴城镇土地使用税的有( )。A.公园中附设的照相馆使用的土地
《工程咨询成果质量评价办法》中,()属于经济分析情况综合评价。A.符合规模
急性梗阻性化脓性胆管炎最主要的治疗措施是( )。A.早期足量应用广谱抗生素
最符合急性肾盂肾炎的是A、发热、水肿、尿频、尿痛及尿沉渣白细胞增多 B、高血压
最新回复
(
0
)