英语听力:自然百科 穿越银河系的旅行 Through Milky Way—2(在线收听

 It's really a wonderful time to be an astronomer, especially in studies of Milk Way. We’re undergoing something for revolution. In fact, we can take you places. They're really quite remarkable.

 
We are about to embark on an amazing journey.
 
We'll take the Earth across thousands of light-years to distant parts of the galaxy, totally different from our own. From these unfamiliar neighborhoods, our skies would appear very different. Skies with not just one, but a multitude of suns. Skies that reveal the power of stars billions of years ago. And what we might see in the future as our sun reaches the end of its life. 
 
With the Hubble Space Telescope, astronomers are able to see billions of other galaxies. Every one is different, but there is a pattern. 
 
“When we look out to study other galaxies in the universe, We see that there are basically two types of galaxies.” 
 
Astronomers call the first type--elliptical galaxies. They appear as large bowls of stars, and no matter what angle they’re viewed from, they always look rounded. Making up the other main class of galaxies, other spiral galaxies. Their stars are contained in arms that spiral/out from their centers. Viewed across their edges, they look a bit like Frisbees. So what type of galaxy is the Milky Way? The answer is written across the night/sky. 
 
”The Milky Way, we believe, is a spiral galaxy. So what we are really seeing when we look up at the night, at this band as we're seeing our place in the universe, we are part of a giant disc of stars. 
 
  原文地址:http://www.tingroom.com/lesson/zrbaike/2011/260141.html