英语听力:自然百科 穿越银河系的旅行 Through Milky Way—7(在线收听

 This is a picture of the Orion Nebula in visible light. We can see all of the gas here located in front of what we know are stars in the background, and we want to be able to look inside this nebula/ and see the stars.

In infrared light in this image, we can now pick out the stars inside the nebula and we can see dusty cocoons around the stars.
 
But to learn the true significance of these stars, we need to strip away the dust all together.
 
How do we get rid of all this haze and fog? The way to do that is with an X-ray picture. Now, when we transit this into the X-ray image, you can see just the stars in cells. The X-ray is coming from the surfaces of the stars. And now we can study them in great detail.
 
By analyzing the light from these stars, astronomers have made an astounding discovery. Hidden within the Orion Nebula/ are some of the youngest stars known, just a few hundred thousand years old, a mere heartbeat in the life of the galaxy. So the Orion Nebula/ is a place where stars are born. And the same thing is happening in nebulae throughout the galaxy spiral arms.
 
These regions are the nurseries for new stars. There are young stars in these regions that are heating up gas clouds that surround them and making those gas clouds glow pink.
 
Stars are made out of gas basically, and our galaxy has gas. In fact, our galaxy, you can think of it, is having an atmosphere of gas and dust that surrounds all of stars that we see in the disc. And it is from this gas that new stars are born.
 
By observing nebulae at different stages in their evolution, we can piece together the story of star birth. It all starts within cold dark clouds of dust and hydrogen gas where a subtle tug-of-war begins. The cloud wants to dissipate like smoke in air, but gravity wants to pull it together.
  原文地址:http://www.tingroom.com/lesson/zrbaike/2011/260148.html