美国国家公共电台 NPR NASA Launches Mission To Retrieve Ancient Asteroid Dust

NASA Launches Mission To Retrieve¹ Ancient Asteroid² Dust 

play pause stop mute unmute max volume 00:0003:12repeat repeat off Update Required To play the media you will need to either update your browser³ to a recent version or update your Flash plugin. STEVE INSKEEP, HOST: 

Tonight, a rocket launches from Cape⁴ Canaveral, Fla. NASA and the University of Arizona are sending a robot to an asteroid that passes by us every six years. They're hoping to gather samples from that asteroid that offer clues to the origin of life. Here's NPR's Rae Ellen Bichell.

RAE ELLEN BICHELL, BYLINE⁵: The asteroid is called Bennu, and it's basically a giant rubble⁶ pile shaped something like a spinning top, but the rubble is very special. Scientists think it's been there, untouched, for about 4 and a half billion years, making it a sort of time capsule. That's why Christina Richey is excited to get a robot there.

CHRISTINA RICHEY: That's a level of understanding we don't have on Earth right now, and that's something we really need.

BICHELL: Richey is one of the people at NASA coordinating⁷ the mission, which is called OSIRIS-REx. She and other scientists think that long ago, asteroids⁸ like this one may have crashed into Earth, delivering organic compounds that turned it into a habitable place for life. If everything goes as planned, a minivan-sized robot will lightly graze the asteroid in mid-2018. It'll inhale⁹ somewhere between a few tablespoons and a few pounds of dust and gravel¹⁰.

RICHEY: We're expecting there to be basically dirt.

BICHELL: A few years ago, a Japanese mission brought back a teeny tiny sample from an asteroid. And in 2006, a NASA mission, called Stardust, plucked ancient dust from a comet.

RICHEY: This is kind of like a follow-on to Stardust only with a way larger sample and with an asteroid versus¹¹ a comet.

BICHELL: Scientists expect to have that sample in 2023.

RICHEY: I am really keen on getting the sample back and having it be pristine¹² and getting to really understand the fundamentals of the origins of our solar system.

BICHELL: But there's another reason scientists are interested in Bennu. There is a tiny chance that the asteroid could whack¹³ into Earth around the end of the next century. Now, there's a 99 percent chance that won't happen, but Bennu is still considered a potential hazard to Earth. That's one reason why scientists have been tracking it for years.

DANTE LAURETTA: Now, we'll have over 20 years of very precise tracking data on this asteroid.

BICHELL: That's Dante Lauretta, a planetary scientist at the University of Arizona and the principal investigator¹⁴ for OSIRIS-REx. Lauretta says the mission will closely monitor the asteroid's path and help confirm if scientists' predictions about its trajectory¹⁵ are correct. There's one thing in particular they want to get a handle on, it's called the Yarkovsky effect. It's one thing that can make asteroid movement hard to predict.

LAURETTA: We've realized that it's a dominant¹⁶ factor in moving the orbits of these small, sub-kilometer asteroids through the solar system.

BICHELL: The idea goes like this, anything close to the sun, including Bennu, absorbs sunlight and then later releases that energy.

LAURETTA: So it gets that energy from the sun, and it pushes that energy back out.

BICHELL: And that subtle burst of energy could be enough to nudge an asteroids path closer to Earth. Loretta and his colleagues want to confirm their projection¹⁷ so they can better predict the paths of near-Earth objects that have a chance, however slim, of causing some serious damage to our planet. So before scooping¹⁸ up that dirt sample, OSIRIS-REx will circle the asteroid for two years measuring how much energy it absorbs and releases and how that changes its path.

LAURETTA: We've always had the tagline of exploring our past and securing our future, and I think we're going to do both of those.

BICHELL: That is, if the mission goes as planned. Rae Ellen Bichell, NPR News.

1 retrieve   

vt.重新得到，收回；挽回，补救；检索

参考例句：

• He was determined to retrieve his honor.他决心恢复名誉。
• The men were trying to retrieve weapons left when the army abandoned the island.士兵们正试图找回军队从该岛撤退时留下的武器。

2 asteroid   

n.小行星；海盘车(动物)

参考例句：

• Astronomers have yet to witness an asteroid impact with another planet.天文学家还没有目击过小行星撞击其它行星。
• It's very unlikely that an asteroid will crash into Earth but the danger exists.小行星撞地球的可能性很小，但这样的危险还是存在的。

3 browser   

n.浏览者

参考例句：

• View edits in a web browser.在浏览器中看编辑的效果。
• I think my browser has a list of shareware links.我想在浏览器中会有一系列的共享软件链接。

4 cape   

n.海角，岬；披肩，短披风

参考例句：

• I long for a trip to the Cape of Good Hope.我渴望到好望角去旅行。
• She was wearing a cape over her dress.她在外套上披着一件披肩。

5 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

6 rubble   

n.（一堆）碎石，瓦砾

参考例句：

• After the earthquake,it took months to clean up the rubble.地震后，花了数月才清理完瓦砾。
• After the war many cities were full of rubble.战后许多城市到处可见颓垣残壁。

7 coordinating   

v.使协调，使调和( coordinate的现在分词 )；协调；协同；成为同等

参考例句：

• He abolished the Operations Coordinating Board and the Planning Board. 他废除了行动协调委员会和计划委员会。 来自辞典例句
• He's coordinating the wedding, and then we're not going to invite him? 他是来协调婚礼的，难道我们不去请他？ 来自电影对白

8 asteroids   

n.小行星( asteroid的名词复数 )；海盘车，海星

参考例句：

• Asteroids,also known as "minor planets",are numerous in the outer space. 小行星，亦称为“小型行星”，在外太空中不计其数。
• Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。

9 inhale   

v.吸入(气体等)，吸(烟)

参考例句：

• Don't inhale dust into your lung.别把灰尘吸进肺里。
• They are pleased to not inhale second hand smoke.他们很高兴他们再也不会吸到二手烟了。

10 gravel   

n.砂跞；砂砾层；结石

参考例句：

• We bought six bags of gravel for the garden path.我们购买了六袋碎石用来铺花园的小路。
• More gravel is needed to fill the hollow in the drive.需要更多的砾石来填平车道上的坑洼。

11 versus   

prep.以…为对手，对；与…相比之下

参考例句：

• The big match tonight is England versus Spain.今晚的大赛是英格兰对西班牙。
• The most exciting game was Harvard versus Yale.最富紧张刺激的球赛是哈佛队对耶鲁队。

12 pristine   

adj.原来的，古时的，原始的，纯净的，无垢的

参考例句：

• He wiped his fingers on his pristine handkerchief.他用他那块洁净的手帕擦手指。
• He wasn't about to blemish that pristine record.他本不想去玷污那清白的过去。

13 whack   

v.敲击，重打，瓜分；n.重击，重打，尝试，一份

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• He gave me a whack on the back to wake me up.他为把我弄醒，在我背上猛拍一下。

14 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。

15 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。

16 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。

17 projection   

n.发射，计划，突出部分

参考例句：

• Projection takes place with a minimum of awareness or conscious control.投射在最少的知觉或意识控制下发生。
• The projection of increases in number of house-holds is correct.对户数增加的推算是正确的。

18 scooping   

n.捞球v.抢先报道( scoop的现在分词 )；（敏捷地）抱起；抢先获得；用铲[勺]等挖（洞等）

参考例句：

• Heated ice cream scoop is used for scooping really cold ice cream. 加热的冰淇淋勺是用来舀非常凉的冰淇淋的。 来自互联网
• The scoop-up was the key phase during a scooping cycle. 3个区间中，铲取区间是整个作业循环的关键。 来自互联网