英语听力：探索发现 2014-06-06 BBC 地平线：陨石的真相-11

 Weknew from the radar¹ measurements where Golevka was within a few tens of metres.And yet it was actually 12 or 15 kilometres away from where it was predicted tobe without Yarkovsky effect. So these very precise radar observations allowedus to see the 12-kilometre displacement² caused by the Yarkovsky effect. 

 

Sophotons, those elementary mass-less particles of light really can create a tinyforce. 

 

Theforce is about one ounce on Earth, say that the weight of a shot glass. That isthe force on this huge asteroid³, the size of a football stadium. Even for me itis truly remarkable⁴. It is dramatic that a force so slight can have suchdramatic changes on an individual asteroid’s orbit over millions of years.  

 

TheYarkovsky effect is subtle. It takes many millions of years to gently nudge anasteroid out of its regular orbit. But once that orbit has been disturbed, theconsequences can be profound. 

 

Nowit can come increasingly under the influence of the solar system’s largestplanet, Jupiter. Jupiter has a mass 300 times bigger than Earth’s, so there isa huge gravitational field. Often that works to our benefit. Stray objects canbe swept up in Jupiter’s gravity, drawing them into the planet. We’ve actuallyobserved Jupiter acting⁵ as a shield in this way. This photograph, from theHubble Space Telescope, shows the fragments of a comet torn apart by Jupiter’sgravity. As the pieces were drawn⁶ to the planet’s atmosphere, the impacts leftblast scars, some as big as the Earth.

1 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。

2 displacement   

n.移置，取代，位移，排水量

参考例句：

• They said that time is the feeling of spatial displacement.他们说时间是空间位移的感觉。
• The displacement of all my energy into caring for the baby.我所有精力都放在了照顾宝宝上。

3 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。

4 remarkable   

adj.显著的，异常的，非凡的，值得注意的

参考例句：

• She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
• These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。

5 acting   

n.演戏，行为，假装；adj.代理的，临时的，演出用的

参考例句：

• Ignore her,she's just acting.别理她，她只是假装的。
• During the seventies,her acting career was in eclipse.在七十年代，她的表演生涯黯然失色。

6 drawn   

v.拖，拉，拔出；adj.憔悴的，紧张的

参考例句：

• All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
• Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。