英语听力：自然百科 穿越银河系的旅行 Through Milky Way—18
时间：2019-01-22 作者：英语课 分类：自然百科2011年
英语课
Measuring the brightnesses and colors of the stars in the globular cluster, we can figure out how old they are. Here is the remarkable 1 thing: they are very old. Globular clusters, at least the stars in the globular clusters, in many cases, are almost as old as the universe itself.
Globular clusters are like living fossils. It’s like discovering a community of people who’s been around since the Stone Age. Some stars here have been shining for 12 billion years, more than twice as long as the sun and that helps to put an age to the Milky 2 Way.
Globular clusters are part of our galaxy 3. They orbit our galaxy, in some sense, they are tracers of our galaxy itself. And so by the fact that the globular clusters are so old, it suggests that the galaxy is so old.
So globular clusters tell us something extraordinary. Our galaxy is one of the oldest objects in the cosmos 4. It’s been around almost since the beginning of the universe, at least 12 billion years. The stars in these clusters also reveal/ that when it first formed, the chemistry of the galaxy was very different from how it is today.
We can measure the chemical properties of those stars. Turns out, they have very low abundances of the heavy elements, things like iron, are very rare in globular cluster stars compared to a star like the sun.
What’s true of / globular clusters is true of the early galaxy. It would have been a far less colorful place, lacking heavy elements which color the nebulae and supernovae remnants we see today. But more importantly, it would have been a galaxy without life. It took billions of years for stars to form enough heavy elements for the evolution of life to begin anywhere in the Milky Way.
adj.显著的，异常的，非凡的，值得注意的
- 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。
adj.牛奶的，多奶的；乳白色的
- Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
- I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。
n.星系；银河系；一群(杰出或著名的人物)
- The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
- The company has a galaxy of talent.该公司拥有一批优秀的人才。