反馈建议 切换旧版 去做题 结束训练
全文精听 逐句精听
句间停顿： 关
  • 关
  • 1S
  • 3S
  • 5S
语速： x 1.0
  • 速度0.8X
  • 速度1.0X
  • 速度1.2X
  • 速度1.5X
  • 速度1.8X
  • 速度2X
始终显示原文
欢迎使用 KMF 精听精研
坚持练习精听，反复听、吃透每个句子，能够快速 提升听力能力
开始精听
或按 「 空格」开始播放

段落1

This is Scientific American 60-Second Science. I'm Christopher Intagliata.

点击显示原文

隐藏原文=

Aside from all the satellites, and the space station orbiting the Earth, there's a lot of trash circling the planet too.

点击显示原文

隐藏原文=

Twenty-one thousand baseball-sized chunks of debris, according to NASA.

点击显示原文

隐藏原文=

But that number's dwarfed by the number of small particles.

点击显示原文

隐藏原文=

There's hundreds of millions of those.

点击显示原文

隐藏原文=

"And those smaller particles tend to be going fast.

点击显示原文

隐藏原文=

So you think of picking up a grain of sand at the beach, and that would be on the large side.

点击显示原文

隐藏原文=

But they're going 60 kilometers per second."

点击显示原文

隐藏原文=

Sigrid Close, an applied physicist and astronautical engineer at Stanford University.

点击显示原文

隐藏原文=

Close says that whereas mechanical damage-like punctures-is the worry with the bigger chunks, the dust-sized stuff might leave more insidious, invisible marks on satellites-by causing electrical damage.

点击显示原文

隐藏原文=

"We also think this phenomenon can be attributed to some of the failures and anomalies we see on orbit, that right now are basically tagged as 'unknown cause.'"

点击显示原文

隐藏原文=

Close and her colleague Alex Fletcher modeled this phenomenon mathematically, based on plasma physics behavior.

点击显示原文

隐藏原文=

And here's what they think happens.

点击显示原文

隐藏原文=

First, the dust slams into the spacecraft. Incredibly fast.

点击显示原文

隐藏原文=

It vaporizes and ionizes a bit of the ship-and itself.

点击显示原文

隐藏原文=

Which generates a cloud of ions and electrons, traveling at different speeds.

点击显示原文

隐藏原文=

And then: "It's like a spring action, the electrons are pulled back to the ions, ions are being pushed ahead a little bit.

点击显示原文

隐藏原文=

And then the electrons overshoot the ions, so they oscillate, and then they go back out again."

点击显示原文

隐藏原文=

That movement of electrons creates a pulse of electromagnetic radiation, which Close says could be the culprit for some of that electrical damage to satellites.

点击显示原文

隐藏原文=

The study is in the journal Physics of Plasmas.

点击显示原文

隐藏原文=

The implications of these small particles on future spaceflight is huge.

点击显示原文

隐藏原文=

"One of my dreams is interstellar travel.

点击显示原文

隐藏原文=

So I love Star Trek, I grew up hoping I could build something to get outside our solar system, and I feel like this is just one of the many things we have to worry about.

点击显示原文

隐藏原文=

I think the space environment as a whole is still something we need to tackle."

点击显示原文

隐藏原文=

Before it tackles any astronauts a long way from home.

点击显示原文

隐藏原文=

Thanks for listening, for Scientific American 60-Second Science. I'm Christopher Intagliata.

点击显示原文

隐藏原文=
[ < 空格 > ]
当前句 /
/
  • 段落1
  • 第 1 句
  • 第 2 句
  • 第 3 句
  • 第 4 句
  • 第 5 句
  • 第 6 句
  • 第 7 句
  • 第 8 句
  • 第 9 句
  • 第 10 句
  • 第 11 句
  • 第 12 句
  • 第 13 句
  • 第 14 句
  • 第 15 句
  • 第 16 句
  • 第 17 句
  • 第 18 句
  • 第 19 句
  • 第 20 句
  • 第 21 句
  • 第 22 句
  • 第 23 句
  • 第 24 句
  • 第 25 句
  • 第 26 句

+ 创建收藏夹
保存 取消