外研版八年级下册英语背景材料 Module 3 Journey to space（打包10份）.zip

Scientists discover Milky Ways youngest exploding star 科学家们发现了银河系中已知的最年轻的超新星。相对于其它同伴来说，这 颗年龄仅 140 岁的超新星就像一个婴儿。 Scientists have announced the discovery of the youngest known exploding star, or supernova (超新星), in our Milky Way galaxy (银河系). Astronomers say the remnant (残骸) of the most recent supernova could provide clues to a long-standing mystery about why so few supernovae seem to explode in our galaxy, compared to other galaxies. Astronomers using NASAs Chandra X-ray Observatory and the Very Large Array radio telescope in New Mexico have discovered the remains of a supernova, known as “G1.9”, which must have lit up our galaxy with a bright flash of light about 140 years ago. At a NASA news conference, scientists said they were able to estimate the age of the supernova by tracking its remnants rate of expansion (扩张) over the last 20 years. They said it expanded by 16 percent a surprisingly large amount indicating it is much younger than previously thought. The scientist who led the study, Stephen Reynolds of North Carolina State University, said radio and X-ray technology allowed scientists to track the dying star through a dense field of gas and dust that had previously obscured the view. The second most recent supernova is believed to have occurred around 1680. Astronomers have been searching for more “missing” supernovae and their remnants. Reynolds explained that scientists had measured the rates of exploding stars in other galaxies, and found out that our own Milky Way galaxy seems to be lagging behind in the number of supernovae per century. Scientists said the discovery of the young remnant would be a “goldmine” to study, since it was still so recent and energetic. They said it was an important finding for understanding the life cycles of stars in the Milky Way galaxy. Bob Kirshner of Harvard University explains why supernovae are important for all of us. “The supernovae make the chemical elements, transforming the light elements into the heavy ones,” he said. “So the calcium that is in your bones and the iron that is in your blood probably came from the supernovae that exploded before the sun formed. So it seems reasonable for us to want to know how these elements get formed when stars explode.” Supernovae and their remnants create the majority of the elements in the universe, spreading everything from cobalt (钴) to gold.Our Milky Way Galaxy: A Travelers Guide Our Milky Way is a barred spiral galaxy containing 400 billion stars bound together by gravity. From Earth, the galaxy has the appearance of a faintly luminous band in the sky. The naked eye cannot resolve the individual stars making up the band, and it was not until the invention of the telescope in the 17th century that it was proved that the Milky Way galaxy contained multitudes of stars. In the early decades of the 20th century, astronomer Edwin Hubble photographed other galaxies and determined that they too are huge systems of many stars, and not just small structures within our own galaxy. The Milky Way is but one among multitudes of galaxies in space. The spiral structure of the Milky Way is obscured by the fact that our Earth, sun and nearby planets are embedded in the galaxys disc. Observation of the shapes of other galaxies led to the realization that ours might be a spiral type. Today, new techniques for measuring distance n deep space are helping astronomers put together a picture of the true shape of our Milky Way galaxy, although much debate remains about details such as the exact shape and location of the spiral arms and central bar.The International Space Station 国际空间站是在国际合作基础上建造的最大载人空间站，为人类进行科学 研究和天文观测提供了技术保障。 The International Space Station (ISS) will be a little “city in space” orbiting (沿 轨道运转) 250 miles above the earth. About the size of two football fields, the space station will be a place where people from around the world can live and study in space over long periods of time. The ISS is an extremely expensive project, but it will someday serve as a stepping-stone for future space exploration. Sixteen countries from around the world are working together on the International Space Station. These international partners are the United States, Russia, Canada, Japan, Brazil and European Space Agency (Belgium, Britain, Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, and Switzerland). Risking the dangers of space, the sixteen countries are spending billions of dollars and many years building the space station because they believe they can benefit a lot from it. Perhaps the most important benefit is that the space station allows humans to live and study for long periods in microgravity (微重力), or a “weightless” environment. Think of the space station as a stepping-stone to the stars. If humans are ever going to travel to other planets, such as Mars, we must understand the effects of such long journeys on the human body. Weve learned from past space travel that living in microgravity leads to the weakening of bones and muscles. The space station will allow scientists to understand these effects and study possible solutions for long-term space travel. But studying in microgravity is not the only reason for the space station. For the first time, we will be able to observe the earth from different angles (角度) over long periods of time. The space station will allow us to watch changes in the environment to better understand our own planet. The space station will also give us an opportunity to study the environment of space.The science of astronomy for kids 浩瀚的宇宙无边无际、无始无终，这给无数人带来了无尽的遐想。它的神 奇和神秘不仅开启了古今中外科学家的探索之路，而且强烈地吸引着孩子们！ The science of astronomy (天文学) is interesting. There are a lot of kids who are interested in the planets, the solar system, the universe and everything else thats part of this exciting science. For children, many parts of it are magical and they are drawn towards the moon, the stars and far distant galaxies (星系). The moon is Earths only satellite. It takes about 27 days to travel around the Earth. Gravity (地心引力) between the moon and Earth causes the tides. Its brightness in the night sky attracts many children to learn more about it. Then theres our sun. Earth is quite far from the sun. The distance is between about 91 million miles and about 94 million miles. Thats because Earths orbit (轨道) around the sun isnt a circle; its an ellipse (椭圆). If there were no sun, we wouldnt be alive. Our light and heat comes from the sun. Over 98% of the total stuff in our solar system is in the sun. Think about how small a person is compared to that. We live in the Milky Way galaxy. Its full of space stuff. Even with all this stuff to fill it, its mostly empty. At over 100,000 light years wide and 3,000 light years high, that means the galaxy holds a whole lot of nothing. The center of our galaxy is about 30,000 light years from Earth. Even with all that space there are about 100 billion stars in the Milky Way. In fact the galaxy was named after the thick group of stars in the main part of it. People thought it looked like a stream of milk, so they called it the Milky Way. There is a lot of information about astronomy for kids on the Internet. Kids can easily learn more about the universe around us.Whats it like in space? 太空是个充满魅力的神奇世界，你知道它到底是什么样子的吗？ When we talk about the universe, we mean the earth, the sun, the moon, the stars and the space between them. Many stars look very small because they are so far away. In fact, some of them are even larger than our sun. Space is large and fascinating. Space contains (包含) every bit of matter and every kind of energy. However, most parts of it are completely empty. In the large empty areas between stars and planets, there are no molecules (分子) to vibrate (振动). So there is no sound there. Space can be beautiful. The planets, stars, galaxies and other things make many beautiful and colourful shapes. We can see them by telescope. Space can be dangerous. In deep space we would die at once if there is nothing to protect us. When the earth travels through space, the atmosphere (大气) keeps us safe. It is like a comfortable blanket to keep the cold and other dangers out.