2006年VOA标准英语-US Launches Decade-Long Mission to Pluto

By David McAlary
Washington
19 January 2006

The United States has launched the first spacecraft to the distant, icy planet Pluto¹.  The distance from Earth is so great the journey will take nine years for a mere² nine-hour fly-by inspection³.  Astronomers⁴ say the results will be worth the wait for what Pluto and its moon Charon can tell us about the origins of the solar system.

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An Atlas⁵ V rocket carries the New Horizons spacecraft   
  

Pluto is the last major planet in our solar system to be visited during four decades of space exploration.  The reason for the lag is not simply because it is more than 6.5 billion kilometers away, 50 times farther than from the Sun to the Earth.

Solar system research director at the U.S. space agency NASA, Andrew Dantzler, says only in the past decade have scientists realized that this icy dwarf⁶, smaller than our moon, might harbor important secrets about the solar system.

"Pluto is a treasure trove⁷ of scientific discoveries just waiting to be uncovered," he said.  "It is different from the inner rocky planets.  It is different from the outer gaseous⁸ planets.  As such, it holds many clues as to how the solar system was formed."

Scientists once thought Pluto orbited in distant solitude⁹.  But last year, astronomers increased their count of its moons to three.  It is also part of a wide swath of perhaps 500,000 small icy worlds circling the sun beyond Neptune¹⁰ called the Kuiper Belt, the first of which was detected in 1992.

The principal investigator¹¹ for the Pluto mission, Alan Stern of the Southwest Research Institute in Colorado, says this belt is the largest structure in the solar system and has opened astronomers' eyes to the diversity of planets.

"Pluto looked like a misfit because it was the only one we saw, and just as a chihuahua is still a dog, these ice dwarfs¹² are still planetary bodies," he explained.  "So the Pluto-like objects are more typical in our solar system than the nearby planets we first knew, and the opportunity is to go now and have a chance to study this most common type of planetary body in the solar system."

Because of Pluto's extreme distance, NASA is employing a lot of power to reduce travel time.  It used its biggest launch rocket, the Atlas Five, to get the spacecraft to a speed approaching 50,000 kilometers per hour within a few minutes, allowing it to pass the moon in only nine hours. 

Alan Stern says the spacecraft will swing by Jupiter in 13 months to take advantage of the planet's huge gravitational pull to increase its speed by 50 percent.  This cuts up to three years off the trip to Pluto.

"We are going farther to reach our target and we are traveling faster than any spacecraft ever has," he said.  "This is a little bit about rewriting the textbooks about the outer planets."

The spacecraft, called New Horizons, is a small probe, the size of a piano, with instruments to study Pluto's atmosphere and icy geology, and its largest moon Charon.  After it passes Pluto, it is to continue into the Kuiper Belt to investigate one or two other bodies.

Its fuel is radioactive plutonium pellets, drawing protests by anti-nuclear activists¹³ who feared a leak during launch could contaminate the environment.  The plutonium will be used mostly for aiming and course corrections.  The spacecraft will not need a lot of power.  Its electronic components¹⁴ use less energy than two 100-watt light bulbs.  For most of its long journey, it will be hibernating¹⁵, sending back only an occasional beacon¹⁶ to relay data on its status. 

The man in charge of the payload is William Gibson, also of the Southwest Research Institute.

"The New Horizons payload, in summary, is the most compact, low power, high performance payload yet to fly on a U.S. planetary mission for a first-reconnaissance fly-by," he said.

In the years before the spacecraft's arrival at Pluto in 2015, the mission team will study the planet with the Hubble Space Telescope to determine if it has more moons and possible rings of dust and rock around which they must navigate¹⁷.  During the fly-by of Jupiter early next year, they will test its navigation and scientific instruments to conduct further inspection of that giant planet.

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 mere   

adj.纯粹的；仅仅，只不过

参考例句：

• That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
• It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。

3 inspection   

n.检查，审查，检阅

参考例句：

• On random inspection the meat was found to be bad.经抽查，发现肉变质了。
• The soldiers lined up for their daily inspection by their officers.士兵们列队接受军官的日常检阅。

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 atlas   

n.地图册，图表集

参考例句：

• He reached down the atlas from the top shelf.他从书架顶层取下地图集。
• The atlas contains forty maps,including three of Great Britain.这本地图集有40幅地图，其中包括3幅英国地图。

6 dwarf   

n.矮子，侏儒，矮小的动植物；vt.使…矮小

参考例句：

• The dwarf's long arms were not proportional to his height.那侏儒的长臂与他的身高不成比例。
• The dwarf shrugged his shoulders and shook his head. 矮子耸耸肩膀，摇摇头。

7 trove   

n.被发现的东西，收藏的东西

参考例句：

• He assembled a rich trove of Chinese porcelain.他收集了一批中国瓷器。
• The gallery is a treasure trove of medieval art.这个画廊是中世纪艺术的宝库。

8 gaseous   

adj.气体的，气态的

参考例句：

• Air whether in the gaseous or liquid state is a fluid.空气，无论是气态的或是液态的，都是一种流体。
• Freon exists both in liquid and gaseous states.氟利昂有液态和气态两种形态。

9 solitude   

n. 孤独; 独居,荒僻之地,幽静的地方

参考例句：

• People need a chance to reflect on spiritual matters in solitude. 人们需要独处的机会来反思精神上的事情。
• They searched for a place where they could live in solitude. 他们寻找一个可以过隐居生活的地方。

10 Neptune   

n.海王星

参考例句：

• Neptune is the furthest planet from the sun.海王星是离太阳最远的行星。
• Neptune turned out to be a dynamic,stormy world.海王星原来是个有生气、多风暴的世界。

11 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。

12 dwarfs   

n.侏儒，矮子（dwarf的复数形式）vt.（使）显得矮小（dwarf的第三人称单数形式）

参考例句：

• Shakespeare dwarfs other dramatists. 莎士比亚使其他剧作家相形见绌。 来自《简明英汉词典》
• The new building dwarfs all the other buildings in the town. 新大楼使城里所有其他建筑物都显得矮小了。 来自辞典例句

13 activists   

n.（政治活动的）积极分子，活动家( activist的名词复数 )

参考例句：

• His research work was attacked by animal rights activists . 他的研究受到了动物权益维护者的抨击。
• Party activists with lower middle class pedigrees are numerous. 党的激进分子中有很多出身于中产阶级下层。 来自《简明英汉词典》

14 components   

（机器、设备等的）构成要素，零件，成分； 成分( component的名词复数 )； [物理化学]组分； [数学]分量； （混合物的）组成部分

参考例句：

• the components of a machine 机器部件
• Our chemistry teacher often reduces a compound to its components in lab. 在实验室中化学老师常把化合物分解为各种成分。

15 hibernating   

（某些动物）冬眠，蛰伏( hibernate的现在分词 )

参考例句：

• The hibernating animals reduce movement to far below the ordinary level. 冬眠的动物把活动量大大减少到低于一般的水平。
• People find hibernating animals asleep. 人们发现冬眠动物处于休眠状态。

16 beacon   

n.烽火，（警告用的）闪火灯，灯塔

参考例句：

• The blink of beacon could be seen for miles.灯塔的光亮在数英里之外都能看见。
• The only light over the deep black sea was the blink shone from the beacon.黑黢黢的海面上唯一的光明就只有灯塔上闪现的亮光了。

17 navigate   

v.航行，飞行；导航，领航

参考例句：

• He was the first man to navigate the Atlantic by air.他是第一个飞越大西洋的人。
• Such boats can navigate on the Nile.这种船可以在尼罗河上航行。