英语听力：自然百科 Planetary Life After Death 浴火重生的行星
时间：2019-01-22 作者：英语课 分类：自然百科2008年
英语课
Like a phoenix 1 rising from the ashes, astronomers 2 have found a whole new solar system may be forming in the wake of a star's violent death.
This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared 3 astronomy with your host Dr. Robert Hurt.
When a massive star reaches the end of the line, it ''does not go gentle into that good night''. It becomes a supernova, an explosion so bright that it briefly 4 outshines everything else in the galaxy 5. Most of the heavy elements that make up planets, and even people, are forged in the nuclear furnaces of such explosions. Here we see heavy elements in the Cassiopeia A supernova remnant blowing back into the galaxy and mingling 6 with interstellar gases. The next generation of baby stars forms from this material now enriched with building blocks for growing new solar systems and planets.
But what of the star that went supernova? Its core still remains 7 in the form of a pulsar. This stellar corpse 8 is tiny and dense 9, squeezing about 1.5 times the mass of the Sun into an object a mere 10 10 miles across.
A team led by Dr. Deepto Chakrabarty at the Massachusetts Institute of Technology has found that even a dead pulsar might play host to a whole new generation of planet formation. They studied a once-massive star that went supernova about 100,000 years ago. In the process it likely wiped out any existing planets. While most of the star-stuff blew off into space, a little bit fell back under the pull of gravity. Dr. Chakrabarty explains. "If the original massive star was spinning fast enough then that material won't fall directly back onto the neutron 11 star, but may instead form a disk, and so what we think we've found is a disk of this debris 12 material that's left over from the explosion that formed the neutron star.
This disk has about 10 times the Earth's mass and looks very much like ones that produce planets around young stars. Moreover, it may help solve a recent planet-making mystery. In 1992, astronomers found the first planets outside our solar system, which were orbiting an older pulsar. But where did they come from? Could they have formed after their star went supernova? The discovery of a planet forming disk around a younger pulsar makes this likely. It seems new planets can arise from the ashes of their own star's death.
However pulsar planets are pretty hostile real estate for life. Pulsars provide little light or heat and would bathe these worlds in intense radiation. A nuclear waste dump at the South Pole might actually be a little more pleasant.
n.凤凰，长生(不死)鸟；引申为重生
- The airline rose like a phoenix from the ashes.这家航空公司又起死回生了。
- The phoenix worship of China is fetish worship not totem adoration.中国凤崇拜是灵物崇拜而非图腾崇拜。
n.天文学者，天文学家( astronomer的名词复数 )
- Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
- Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》
adj./n.红外线(的)
- Infrared is widely used in industry and medical science.红外线广泛应用于工业和医学科学。
- Infrared radiation has wavelengths longer than those of visible light.红外辐射的波长比可见光的波长长。
adv.简单地，简短地
- I want to touch briefly on another aspect of the problem.我想简单地谈一下这个问题的另一方面。
- He was kidnapped and briefly detained by a terrorist group.他被一个恐怖组织绑架并短暂拘禁。
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。
adj.混合的
- There was a spring of bitterness mingling with that fountain of sweets. 在这个甜蜜的源泉中间，已经掺和进苦涩的山水了。
- The mingling of inconsequence belongs to us all. 这场矛盾混和物是我们大家所共有的。
n.剩余物，残留物；遗体，遗迹
- He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
- The remains of the meal were fed to the dog.残羹剩饭喂狗了。
n.尸体，死尸
- What she saw was just an unfeeling corpse.她见到的只是一具全无感觉的尸体。
- The corpse was preserved from decay by embalming.尸体用香料涂抹以防腐烂。
a.密集的，稠密的，浓密的；密度大的
- The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
- The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。
adj.纯粹的；仅仅，只不过
- That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
- It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。
n.中子
- Neutron is neutral and slightly heavier than the proton.中子是中性的，比质子略重。
- Based on the neutron energy,the value of weighting factor was given.根据中子能量给出了相应的辐射权重因子的数值。