2007年VOA标准英语-Two New US Spacecraft Offer Better Warning of S

By David McAlary
Washington
01 March 2007

The U.S. space agency NASA says two new spacecraft orbiting Earth are giving scientists an unprecedented¹ ability to track storms on the sun all the way to Earth. As VOA's David McAlary reports from Washington, the satellites will help the government provide the earliest warnings yet of solar blasts than can disrupt electrical systems.

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View of solar flares from two new NASA spacecraft

Two spacecraft launched on a single rocket last October are giving scientists their first complete view of the life of a solar eruption³, from its development on the sun's surface to the arrival of its surge at Earth.

These radiation blasts contain billions of tons of electrically charged gas from the sun's atmosphere, or corona⁴, and travel at speeds up to 1.5 million kilometers per hour. When they slam into the more slowly moving cloud of charged particles called the solar wind, they create a shock that accelerates the particles.

This onslaught creates the brilliant auroras at the poles, but can also disrupt power grids⁵ on Earth and sensitive electronics in spacecraft, and also harm unshielded astronauts.

The twin spacecraft tracking these blasts, called STEREO-A and STEREO-B, are still heading toward their final optimal⁶ viewing orbits, but one mission scientist says their early images of recent solar blasts are exciting.

"This is really the first time we have had such a complete view of this inner heliosphere, this very vast region between the sun and Earth," said Russell Howard of the U.S. Naval⁷ Research Laboratory. He says no previous spacecraft watching the sun has had such a sweeping⁸ view of the path of solar radiation blasts, which scientists call coronal mass ejections, or CMEs.

"It enables us to track CMEs from their origin at the sun all the way to the orbit of Earth. These images demonstrate the capability⁹ and promise of really great things to come," he said.

The twin spacecraft are to lengthen¹⁰ the warning time of the sun's radiation bombardments by providing a stereoscopic view of the particle clouds. Right now, the satellites are separated by only one degree from each other, but they continue widening the gap, and, eventually, will be stationed in Earth orbit 500,000 kilometers apart.

The separation will give depth perception, like our eyes do by being separated in our heads. Mission officials say this will offer a better idea of the direction the solar particle surge is moving and when it will arrive at Earth, allowing the government to warn operators of spacecraft and electrical grids to protect them.

Howard says even the early views with the two spacecraft still close together have provided new information about the shape and speed of coronal mass ejection clouds.

"This panoramic¹¹ view is absolutely unique. So, even though we are not seeing the CMEs necessarily the best way coming toward Earth, the way we will when there is some separation, we are still seeing the evolution of this material as it goes out into interplanetary space, and we are already seeing that interaction with the solar wind. So, it is quite useful," he said.

The STEREO mission is to last two years.

1 unprecedented   

adj.无前例的，新奇的

参考例句：

• The air crash caused an unprecedented number of deaths.这次空难的死亡人数是空前的。
• A flood of this sort is really unprecedented.这样大的洪水真是十年九不遇。

2 flares   

n.喇叭裤v.（使）闪耀( flare的第三人称单数 )；（使）（船舷）外倾；（使）鼻孔张大；（使）（衣裙、酒杯等）呈喇叭形展开

参考例句：

• The side of a ship flares from the keel to the deck. 船舷从龙骨向甲板外倾。 来自《简明英汉词典》
• He's got a fiery temper and flares up at the slightest provocation. 他是火爆性子，一点就着。 来自《现代汉英综合大词典》

3 eruption   

n.火山爆发；（战争等）爆发；（疾病等）发作

参考例句：

• The temple was destroyed in the violent eruption of 1470 BC.庙宇在公元前1470年猛烈的火山爆发中摧毁了。
• The eruption of a volcano is spontaneous.火山的爆发是自发的。

4 corona   

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。

5 grids   

n.格子( grid的名词复数 )；地图上的坐标方格；（输电线路、天然气管道等的）系统网络；（汽车比赛）赛车起跑线

参考例句：

• Typical framed structures are beams, grids, plane and space frames or trusses. 典型构架结构为梁、格栅、平面的和空间的框架或桁架。 来自辞典例句
• The machines deliver trimmed grids for use or stock. 这种机器铸出修整过的板栅，以供使用或储存。 来自辞典例句

6 optimal   

adj.最适宜的；最理想的；最令人满意的

参考例句：

• What is the optimal mix of private and public property rights in natural resources?私人和国家的自然资源产权的最适宜的组合是什么？
• Optimal path planning is a key link for the sailing contest.帆船最优行驶路径规划是帆船比赛取胜的关键环节。

7 naval   

adj.海军的，军舰的，船的

参考例句：

• He took part in a great naval battle.他参加了一次大海战。
• The harbour is an important naval base.该港是一个重要的海军基地。

8 sweeping   

adj.范围广大的，一扫无遗的

参考例句：

• The citizens voted for sweeping reforms.公民投票支持全面的改革。
• Can you hear the wind sweeping through the branches?你能听到风掠过树枝的声音吗？

9 capability   

n.能力；才能；(pl)可发展的能力或特性等

参考例句：

• She has the capability to become a very fine actress.她有潜力成为杰出演员。
• Organizing a whole department is beyond his capability.组织整个部门是他能力以外的事。

10 lengthen   

vt.使伸长，延长

参考例句：

• He asked the tailor to lengthen his coat.他请裁缝把他的外衣放长些。
• The teacher told her to lengthen her paper out.老师让她把论文加长。

11 panoramic   

adj. 全景的

参考例句：

• Most rooms enjoy panoramic views of the sea. 大多数房间都能看到海的全景。
• In a panoramic survey of nature, speed is interesting because it has a ceiling. 概观自然全景，速率是有趣的，因为它有一个上限。