美航天局观测到彗星撞击太阳景象-凯发k8官网

美航天局观测到彗星撞击太阳景象
文章来源:未知 文章作者:meng 发布时间:2010-05-25 05:50 字体: [ ] 
(单词翻译:双击或拖选)

solar 1 at the university of california, berkeley, have captured for the first time the collision of a comet with the sun. using instruments aboard nasa's twin stereo spacecraft, four post-doctoral fellows at uc berkeley's space sciences laboratory were able to track the comet(彗星) as it approached the sun and estimate an approximate time and place of impact. stereo (solar terrestrial relations observatory日地天文台), launched in 2006, consists of identical spacecraft orbiting the sun, one ahead of earth and one behind earth, providing a stereo view of the sun.

the researchers then looked at data from the ground-based mauna loa solar 2 in hawaii, and found images in the predicted spot of what appears to be a comet approaching the edge of the sun from behind the solar disk.

"we believe this is the first time a comet has been tracked in 3-d space this low down in the solar 3(日冕) ," said claire raftery, a post-doctoral fellow newly arrived at uc berkeley from dublin's trinity college.

the team will present its data and images during a 5:30-6:30 p.m. poster session on monday, may 24, at the miami, fla., meeting of the american 4 society.

sungrazing comets(掠日彗星) , comprised of dust, rock and ice, are seldom tracked close to the sun because their brightness is overwhelmed by the solar disk. this comet 5 survived the heat of the corona and disappeared in the 6(色球层) , evaporating(蒸发) in the 100,000-degree (kelvin) heat.

raftery and her colleagues, juan carlos martinez-oliveros, samuel krucker and pascal saint-hilaire, concluded that the comet was probably one of the kreutz family of comets, a 7 of(一大群) trojan or greek comets ejected from their orbit in 2004 by jupiter, and that it made its first and only loop around the sun. the swarm probably resulted from the 8(分解,瓦解) of a larger comet.

martinez-oliveros' attention was first 9 to the comet after seeing it mentioned in a summary of march 12, 2010, observations by stereo and by soho, the solar and heliospheric observatory. the comet's long, bright tail of dust and ions tagged it as a sungrazing comet seen often by solar 10 and 11 such as stereo.

assuming it was a going to loop around the sun, the researchers 12 to see whether the stereo data were good enough to let them calculate its 13(弹道,轨道) .

in fact, the data were good enough to chart the comet's approach for two days before impact.

with an estimate of the impact zone within a circle about 1,000 kilometers in diameter, they searched online data from the mauna loa solar observatory to determine if they could see the comet next to the sun's edge in the ultraviolet region of the 14.

they found a short track, 15 about six minutes, just a few thousand kilometers above the sun's surface in the million-degree corona and 100,000-degree chromosphere.

based on the comet's 16 short tail, about 3 million kilometers in length, the researchers believe that the comet contained heavier elements that do not evaporate readily. this would also explain how it 17 so deeply into the chromosphere, surviving the strong solar wind as well as the extreme temperatures, before evaporating.

for their study, the team used the two coronagraphs on stereo a and b and multiple instruments on soho, "demonstrat(ing) the importance of multi-view observations of non solar phenomena," they wrote in their poster.

all members of the team study explosive events on the sun, such as coronal mass ejections, and the hot ionized plasmas(等离子体) that they throw into space. the researchers' 18(便道,绕道) into cometary physics was 19 accidental, they said.

"it was supposed to be an exercise, but it took over our lives," raftery said.



点击收听单词发音收听单词发音  

1 18316b43c980524885c1a898ed1528b1     
物理学家( physicist的名词复数 )
参考例句:
  • for many particle physicists, however, it was a year of frustration. 对于许多粒子物理学家来说,这是受挫折的一年。 来自英汉非文学 - 科技
  • physicists seek rules or patterns to provide a framework. 物理学家寻求用法则或图式来构成一个框架。
2 hrgzp     
n.天文台,气象台,瞭望台,观测台
参考例句:
  • guy's house was close to the observatory.盖伊的房子离天文台很近。
  • officials from greenwich observatory have the clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。
3 jy4z4     
n.日冕
参考例句:
  • the corona gains and loses energy continuously.日冕总是不断地获得能量和损失能量。
  • the corona is a brilliant,pearly white,filmy light,about as bright as the full moon.光环带是一种灿烂的珠白色朦胧光,几乎像满月一样明亮。
4 ketyo     
adj.天文学的,(数字)极大的
参考例句:
  • he was an expert on ancient chinese astronomical literature.他是研究中国古代天文学文献的专家。
  • houses in the village are selling for astronomical prices.乡村的房价正在飙升。
5 tmmyq     
adv.显然地;表面上,似乎
参考例句:
  • an apparently blind alley leads suddenly into an open space.山穷水尽,豁然开朗。
  • he was apparently much surprised at the news.他对那个消息显然感到十分惊异。
6 zrkzy     
n.色球
参考例句:
  • it is difficult to photograph the actual chromosphere.拍摄实际的色球层很困难。
  • the chromosphere is a frothy layer churned up by gases in the photosphere.色球层在光球层气体的搅拌下是个多泡层。
7 dqlyj     
n.(昆虫)等一大群;vi.成群飞舞;蜂拥而入
参考例句:
  • there is a swarm of bees in the tree.这树上有一窝蜜蜂。
  • a swarm of ants are moving busily.一群蚂蚁正在忙碌地搬家。
8 ttjxi     
n.分散,解体
参考例句:
  • this defeat led to the disintegration of the empire.这次战败道致了帝国的瓦解。
  • the incident has hastened the disintegration of the club.这一事件加速了该俱乐部的解体。
9 muxzii     
v.拖,拉,拔出;adj.憔悴的,紧张的
参考例句:
  • all the characters in the story are drawn from life.故事中的所有人物都取材于生活。
  • her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。
10 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》
11 d730b278442c711432218e89314e2a09     
n.天文台,气象台( observatory的名词复数 )
参考例句:
  • john heilbron, the sun in the church: cathedrals as solar observatories, 3-23. 约翰.海耳布隆,《教会里的太阳:教堂即太阳观测台》,第3-23页。 来自互联网
  • meteorologists use satellites, land observatories and historical data to provide information about the weather. 气象学家使用卫星、上天文台和历史资料来提供有关天气的信息。 来自互联网
12 lvqzzd     
adj.决定了的,坚决的;明显的,明确的
参考例句:
  • this gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
  • there is a decided difference between british and chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。
13 fj1z1     
n.弹道,轨道
参考例句:
  • it is not difficult to sketch the subsequent trajectory.很容易描绘出它们最终的轨迹。
  • the path followed by a projectile is called its trajectory.抛物体所循的路径称为它的轨道。
14 trhy6     
n.谱,光谱,频谱;范围,幅度,系列
参考例句:
  • this is a kind of atomic spectrum.这是一种原子光谱。
  • we have known much of the constitution of the solar spectrum.关于太阳光谱的构成,我们已了解不少。
15 ipcz02     
adj.永久的,永恒的;vbl.持续,维持
参考例句:
  • the lasting war debased the value of the dollar.持久的战争使美元贬值。
  • we hope for a lasting settlement of all these troubles.我们希望这些纠纷能获得永久的解决。
16 bkqzs3     
adv.比较...地,相对地
参考例句:
  • the rabbit is a relatively recent introduction in australia.兔子是相对较新引入澳大利亚的物种。
  • the operation was relatively painless.手术相对来说不痛。
17 61c8e5905df30b8828694a7dc4c3a3e0     
adj. 击穿的,鞭辟入里的 动词penetrate的过去式和过去分词形式
参考例句:
  • the knife had penetrated his chest. 刀子刺入了他的胸膛。
  • they penetrated into territory where no man had ever gone before. 他们已进入先前没人去过的地区。
18 blszz     
n.绕行的路,迂回路;v.迂回,绕道
参考例句:
  • we made a detour to avoid the heavy traffic.我们绕道走,避开繁忙的交通。
  • he did not take the direct route to his home,but made a detour around the outskirts of the city.他没有直接回家,而是绕到市郊兜了个圈子。
19 8sqxf     
adv.纯粹地,完全地
参考例句:
  • i helped him purely and simply out of friendship.我帮他纯粹是出于友情。
  • this disproves the theory that children are purely imitative.这证明认为儿童只会单纯地模仿的理论是站不住脚的。
tag标签: spacecraft sun nasa comet
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:点击我更换图片
网站地图