2007年VOA标准英语-US Spacecraft Takes New Look at Jupiter on Way

By David McAlary
Washington
28 February 2007

A U.S. spacecraft has taken the closest images of Jupiter since the Galileo probe perished in a programmed dive into the huge planet's atmosphere four years ago. The spacecraft's destination is icy, distant Pluto¹, but the U.S. space agency NASA wanted to fly close to Jupiter on the way out to get a scientific update and a speed boost. VOA's David McAlary reports.

 
New Horizons spacecraft 
More than 13 months after its launch, NASA's New Horizons spacecraft has made its closest pass to Jupiter on its 10-year voyage to Pluto. The head of NASA's science directorate and chief investigator² for the mission, Alan Stern, says the flyby has been eagerly awaited.

"Between the demise³ of Galileo with the end of its very successful mission in 2003 and the arrival of the Juno Jupiter orbiter that we are all looking forward to in 2016, this is the only train going this way," said Alan Stern.

 
Jupiter's Little Red Spot 
New Horizons has been taking pictures of Jupiter since January and will continue to dispatch them through June, but the close pass more than two million kilometers away is giving astronomers⁴ another detailed⁵ look at the gas giant, its rings, and its four biggest moons.

A mission scientist from the Southwest Research Institute in Boulder⁶, Colorado, John Spencer, spoke⁷ of the goals before Wednesday's Jupiter pass.

"We very carefully tailored our observations so we will be not repeating things that have have been done by the other seven missions that have already been to Jupiter," said John Spencer. "Sometimes we are just looking for changes."

 
Jupiter flyby trajectory⁸
The observations have included Jupiter's auroras and its giant red spot, a swirling⁹ centuries-old storm larger than Earth. New Horizons' advanced instruments have also peered at the planet's rings in an effort to find more tiny moons. In addition, it studied the surface composition of the big moons Gannymede; Callisto; Io, which has a volcano; and Europa, which is thought to have a liquid water ocean under a shell of ice.

The spacecraft will also become the first to take a trip down the long tail of Jupiter's magnetosphere, a wide stream of charged particles extending tens of millions of kilometers.

Alan Stern says the observations are intended as practice for the duties New Horizons faces at Pluto when it arrives in 2015.

"We have designed this particular flyby to be a stress test on our spacecraft to work out the kinks so that at Pluto, we do not learn a thing about our spacecraft, we have worked out those kinks at Jupiter, putting our spacecraft through 700 different observations," he said.

These observations are only one reason for the visit to Jupiter. The pass also lets the planet's strong gravity sling¹⁰ it away, providing a 14,000 - kilometer per hour speed boost. This cuts the spacecraft's flight time to Pluto by three years.

After the Jupiter encounter, New Horizons' electronics will become dormant¹¹ for much of its cruise. Mission controllers will shut off all but the most critical systems and check in once a year to test those systems, calibrate¹² instruments, and correct the course if needed.

1 Pluto   

n.冥王星

参考例句：

• Pluto is the furthest planet from the sun.冥王星是离太阳最远的行星。
• Pluto has an elliptic orbit.冥王星的轨道是椭圆形的。

2 investigator   

n.研究者，调查者，审查者

参考例句：

• He was a special investigator for the FBI.他是联邦调查局的特别调查员。
• The investigator was able to deduce the crime and find the criminal.调查者能够推出犯罪过程并锁定罪犯。

3 demise   

n.死亡；v.让渡，遗赠，转让

参考例句：

• He praised the union's aims but predicted its early demise.他赞扬协会的目标，但预期这一协会很快会消亡。
• The war brought about the industry's sudden demise.战争道致这个行业就这么突然垮了。

4 astronomers   

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》

5 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

6 boulder   

n.巨砾；卵石，圆石

参考例句：

• We all heaved together and removed the boulder.大家一齐用劲，把大石头搬开了。
• He stepped clear of the boulder.他从大石头后面走了出来。

7 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

8 trajectory   

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。

9 swirling   

v.旋转，打旋( swirl的现在分词 )

参考例句：

• Snowflakes were swirling in the air. 天空飘洒着雪花。 来自《现代汉英综合大词典》
• She smiled, swirling the wine in her glass. 她微笑着，旋动着杯子里的葡萄酒。 来自辞典例句

10 sling   

vt.扔；悬挂；n.挂带；吊索，吊兜；弹弓

参考例句：

• The boy discharged a stone from a sling.这个男孩用弹弓射石头。
• By using a hoist the movers were able to sling the piano to the third floor.搬运工人用吊车才把钢琴吊到3楼。

11 dormant   

adj.暂停活动的；休眠的；潜伏的

参考例句：

• Many animals are in a dormant state during winter.在冬天许多动物都处于睡眠状态。
• This dormant volcano suddenly fired up.这座休眠火山突然爆发了。

12 calibrate   

校准；使合标准；测量（枪的）口径

参考例句：

• Pesticide levels in food are simply too difficult to calibrate.食品中杀虫剂的含量很难精确测定。