英语听力:探索发现 2014-05-18 BBC 地平线:陨石的真相-4(在线收听

 Amazing images. But what can you get out of these asan expert?

 
What it shows us, first of all, is a great record ofthe entry of the object into the Earth’s atmosphere. So you see it right fromthe moment it really penetrated. And there it is.
 
That is the edge of the atmosphere?
 
That’s it and it’s coming down at a fairly shallowangle probably and as we play the movie on, what we see is, bang there, firstof all, it suddenly got brighter. So something’s happened to the object. It’sstarting to break apart and as it breaks apart, it releases some of its orbitalenergy. And that’s causing that big flare up there. 
 
And is that because the atmosphere is denser, it isharder?
 
That’s right. It’s finding it harder and harder topunch through the atmosphere. And as we roll on, we suddenly get this bang,this huge flare up where suddenly the whole object is starting to fragment andbreak apart. And that’s where the majority of the energy is being released. 
 
If we look here..
 
There are just little bits coming, falling off.
 
That’s right. There is another flare up there andthere is another flare up there. And now we can still see it’s glowingincandescent. Some major fragment of the object is still falling down throughthe Earth’s atmosphere. Underneath the trajectory you are going to have showersof bits of asteroid, essentially falling down, and then finally 16.5 secondslater, and what we are left with is this contour trail. And invisibly..
 
The shockwave. 
 
The shockwave coming towards us. Yeah, that isright. And itis about a minute later that it’s gone and reached the ground. 
 
This guy driving doesn’t know yet that the shockwaveis on its way here. 
 
That is right. He is still happily listening to theradio on his drive to work in the morning.
  原文地址:http://www.tingroom.com/lesson/yytltsfx/2014/273520.html