VOA标准英语2013--欧洲太空总署绘制银河系的3D地图

 

ESA to Make 3D Map of Milky¹ Way 欧洲太空总署绘制银河系的3D地图

The European Space Agency this week successfully launched the star-mapping satellite Gaia on a mission that will take it more than a million kilometers from Earth - to  create the first three-dimensional (3D) map of our galaxy², the Milky Way.

The two-ton satellite, launched from the European Space Agency’s center in French Guiana aboard a Russian Soyuz rocket, reached the initial orbit and deployed³ a 10- meter circular sunshield to keep the instruments on-board, including a telescope, cool.  In order to focus on very distant and faint stars, Gaia has to be mechanically  and thermally⁴ stable, so it has almost no moving parts.

Mark McCaughrean, the mission's chief scientist, says, “It will measure the positions of a billion stars but also their speeds, their motions. And with that we can  run a movie of the Milky Way.  We can run it forwards, into the future, how the Milky Way will develop by looking at all the stars and how they move. But we can run it  backwards as well, and we can see how the Milky Way actually formed in the first place.”

Gerard F. Gilmore, a professor at Cambridge University's Institute of Astronomy, says the three-dimensional picture will eventually cover half of the Milky Way and  provide new knowledge about what keeps it together.

“And the particular interest that I have in here, locally, is in the nature of dark matter," he said. "What is dark matter made of? Dark matter is most of the weight  in the Milky Way. It is dark matter that holds the Milky Way together. If there weren′t all this dark material, our sun would fly off...away from the galaxy. The  whole galaxy would fall apart.”

The Gaia satellite will be moved to a distance of 1.5 million kilometers from Earth, to a gravitationally stable point called L2, where it will start its five-year  mission of taking approximately 70 images of each star in our galaxy, building a catalog of about one billion stars.

L2 is also designated as the parking space for NASA’s supersensitive infrared⁵ James Webb Space Telescope, scheduled for launch in 2018.

The overal cost of the Gaia mission is around $1.3 billion.

1 milky   

adj.牛奶的，多奶的；乳白色的

参考例句：

• Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
• I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。

2 galaxy   

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。

3 deployed   

（尤指军事行动）使展开( deploy的过去式和过去分词 )； 施展； 部署； 有效地利用

参考例句：

• Tanks have been deployed all along the front line. 沿整个前线已部署了坦克。
• The artillery was deployed to bear on the fort. 火炮是对着那个碉堡部署的。

4 thermally   

热地

参考例句：

• The magnetizing field is then removed while the body is thermally isolated. 在该物体热绝缘时把磁场撤去。
• They could thermally desorb these ions by heating the foil to red heat. 他们通过加热金属箔至红热以解吸这些离子。

5 infrared   

adj./n.红外线(的)

参考例句：

• Infrared is widely used in industry and medical science.红外线广泛应用于工业和医学科学。
• Infrared radiation has wavelengths longer than those of visible light.红外辐射的波长比可见光的波长长。