glimpses of solar system's edge 太阳系边缘一瞥-凯发k8官网

glimpses of solar system's edge 太阳系边缘一瞥
文章来源:未知 文章作者:meng 发布时间:2009-10-16 05:06 字体: [ ] 
(单词翻译:双击或拖选)

the first results from nasa's interstellar boundary explorer (ibex) spacecraft have shown unexpected features at our solar system's edge.

美国航空航天局的星际边界探测器第一次探测结果显示了我们太阳系边缘出乎意料的特征。

1" width="466" border="0" src="/upimg/091016/4_052625_1.jpg" />
the flow of particles into our solar neighbourhood is uneven

ibex was launched nearly one year ago to map the heliosphere(日光层), the region of space defined by the extent of our sun's solar wind.

ibex's first glimpses show that the heliosphere is not shaped as many 2 have believed.

a series of papers in the journal science outlines the results.

our solar system is whipping around the centre of the 3. just like a hand held out of a moving car, the solar system feels a "wind" of particles from the region between our star and its nearest neighbours.

at the same time, the solar wind - a constant stream of fast-moving particles(粒子) in all directions - blows 4 from the sun.

the boundary at which the incoming and outgoing particles are at equivalent pressures, known as the heliopause(太阳风层顶), defines the heliosphere - the "bubble" in space generated by our own sun's exhalations.

true shape

the true extent and shape of the heliosphere has been a subject of debate for more than half a century. until now, the best clues came from the two voyager spacecraft, which are believed to have passed through the heliopause at two different distances.

through a process known as "charge exchange" at the heliosphere's edge, fast-moving neutral(中立的) or uncharged particles are created, and it is these energetic neutral atoms or enas that the ibex spacecraft aims to measure.

it orbits the earth in a vast ellipse(椭圆), 5 incoming enas flying back from the heliopause at a range of speeds.

what a number of researchers have found is that the flow of the enas is uneven(不均匀的,奇数的), with a significantly higher flow in a "ribbon" across the sky.

"the ibex results are truly 6, with 7 not resembling any of the current theories or models of this never-before-seen region," said lead researcher dr david mccomas of the southwest research institute in new mexico.

"we expected to see small, gradual 8(空间的) variations at the interstellar(星际的) boundary. however, ibex is showing us a very narrow ribbon that is two to three times brighter than anything else in the sky."

near miss

these concentrations of incoming particles were just missed by the voyager spacecraft, dr mccomas explained.

"the most 9(令人惊骇的) feature in the ibex sky maps - the bright narrow ribbon - snakes through the sky between the voyager spacecraft, where it remained completely undetected until now," he said.

further measurements were made by the cassini spacecraft orbiting 10. it too has a "camera" that can capture incoming neutral atoms, and also observed a ribbon-shaped region across the sky, but from enas moving at slightly different speeds.

what is clear is that the heliosphere is not shaped like a comet(彗星), as 11 thought, with a head 12 at the oncoming interstellar medium(星际介质) and a tail of matter trailing behind.

the research groups agree that the magnetic field(磁场) interactions at the heliopause have as-yet undetermined effects on the overall shape. but the exact shape, and the forces that cause it, are still a matter of debate between the teams.



点击收听单词发音收听单词发音  

1 akwwb     
adj.不平坦的,不规则的,不均匀的
参考例句:
  • the sidewalk is very uneven—be careful where you walk.这人行道凹凸不平—走路时请小心。
  • the country was noted for its uneven distribution of land resources.这个国家以土地资源分布不均匀出名。
2 569155f16962e086bd7de77deceefcbd     
n.天文学者,天文学家( astronomer的名词复数 )
参考例句:
  • astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
  • astronomers used to ask why only saturn has rings. 天文学家们过去一直感到奇怪,为什么只有土星有光环。 来自《简明英汉词典》
3 ohoxb     
n.星系;银河系;一群(杰出或著名的人物)
参考例句:
  • the earth is one of the planets in the galaxy.地球是银河系中的星球之一。
  • the company has a galaxy of talent.该公司拥有一批优秀的人才。
4 njuxn     
adj.外面的,公开的,向外的;adv.向外;n.外形
参考例句:
  • does this door open inwards or outwards?这门朝里开还是朝外开?
  • in lapping up a fur,they always put the inner side outwards.卷毛皮时,他们总是让内层朝外。
5 chmxz     
n.集会,聚会,聚集
参考例句:
  • he called on mr. white to speak at the gathering.他请怀特先生在集会上讲话。
  • he is on the wing gathering material for his novels.他正忙于为他的小说收集资料。
6 8vbx6     
adj.显著的,异常的,非凡的,值得注意的
参考例句:
  • she has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
  • these cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。
7 1a87f8769eb755734e056efecb5e2da9     
排放物( emission的名词复数 ); 散发物(尤指气体)
参考例句:
  • most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
  • dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。
8 gvcww     
adj.空间的,占据空间的
参考例句:
  • this part of brain judges the spatial relationship between objects.大脑的这部分判断物体间的空间关系。
  • they said that time is the feeling of spatial displacement.他们说时间是空间位移的感觉。
9 qykzns     
adj.使人震惊的vt.使震惊,使大吃一惊astound的现在分词)
参考例句:
  • there was an astounding 20% increase in sales. 销售量惊人地增加了20%。
  • the chairman's remarks were so astounding that the audience listened to him with bated breath. 主席说的话令人吃惊,所以听众都屏息听他说。 来自《简明英汉词典》
10 tszy1     
n.农神,土星
参考例句:
  • astronomers used to ask why only saturn has rings.天文学家们过去一直感到奇怪,为什么只有土星有光环。
  • these comparisons suggested that saturn is made of lighter materials.这些比较告诉我们,土星由较轻的物质构成。
11 bkzzzc     
adv.以前,先前(地)
参考例句:
  • the bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
12 il8zb4     
adj.尖的,直截了当的
参考例句:
  • he gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
  • she wished to show mrs.john dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。
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