Учебное пособие Астрономия. Космическая техника и технологии Алматы, 2012 удк 802. 0 52 629. 7 (0758) ббк 81. Англ. 923
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Discussion Questions 1 Discuss why some scientists were uneasy about the idea of an expanding universe? 2 Astronomer Wendy Freedman's observations of Cepheid variable stars in another galaxy indicated that the age of the universe is about eight-twelve billion years. Why did her discovery cause such a debate among astronomers? What elements of her discovery still lend them to argument? 3 What do scientists learn by observing parts of the universe in other than the visible parts of the spectrum? 4 What materials are believed to compose dark matter, and what can we learn about the universe by examining it? Unit 3 Solar System Text 3 A Soaring Through Our Solar System By Laura G. Smith  Five, four, three, two, one... BLAST OFF! Come along as we explore our solar system! If we were flying high above the Earth, what would you see? The biggest, brightest thing you would see is the sun. You would also see many objects traveling around the sun, including the Earth and its moon! The sun, planets, and moons are all part of our solar system. The sun is a huge star in the middle of the solar system. It is the only star we can see during the day. The sun is much brighter than the stars we see at night, because it is much closer to the Earth. It is made of gases that are released in the form of light and heat. The planets are all different sizes. Pluto, the smallest planet, is tinier than the Earth's moon. Jupiter is the largest planet. It is eleven times wider than the Earth! All nine of the planets are much smaller than the sun. If you had a hollow ball the size of the sun, you could fit one million balls the size of the Earth inside it! All of the planets in our solar system move around the sun in an oval path called an orbit. This path is shaped something like an egg. The sun has a strong force that pulls all of the planets toward it. This force, called gravity, is what makes the planets stay in their orbits. As each planet orbits the sun, it is also spinning around like a top. This spinning is called rotation. Each planet rotates at a different speed. It takes Jupiter less than 10 hours to rotate one time, but it takes Venus 243 days! The planets can be divided into two groups. The first group is called the inner planets. The second group is the outer planets. The inner planets-Mercury, Venus, Earth, and Mars-are smaller and are made of mostly rock and iron. Jupiter, Saturn, Uranus, and Neptune make up the outer planets, which are much larger. They are made mostly of hydrogen, helium, and ice. Pluto is the smallest planet and the farthest from Earth. Because it is so far away, scientists don't know very much about it. Some scientists think it shouldn't even be included as one of the nine planets. There are more than 120 moons that orbit the planets in our solar system. Some planets, like the Earth, only have one moon. Other planets, like Jupiter and Saturn, have as many as 30 moons traveling around them! Besides the nine planets and their moons, there are thousands of other, smaller objects in our solar system. These are small chunks of rocks called asteroids. The tiniest asteroids are less than a mile wide. The largest is over 600 miles wide. Small chunks of iron and rock that break away from asteroids are called meteoroids. Many meteoroids fall close to the Earth. Most of them burn up before they reach the Earth's surface. Meteoroids that fall through the sky like streaks of light are called meteors or "shooting stars." When a meteoroid is found on the Earth's surface, it is called a meteorite. Scientists can study meteorites to learn important facts about our solar system. Comets are another part of our solar system. They travel around the sun just like the planets. A comet looks like a fuzzy star with a long tail. It is made of frozen gases, ice, and bits of dust. Every comet takes a different amount of time to make a full orbit. One famous comet called "Halley's Comet" takes about 77 years to orbit once around the sun. When the telescope was invented in the early 1600's, scientists began to learn much more about the sun, planets, moons, asteroids, meteoroids, and comets that make up our solar system. A long time ago, before we had telescopes, people thought the Earth was in the centre of space and that the sun and other stars orbited around it! Today, with the help of spaceships and other equipment, man is learning even more about our amazing solar system! Choose the correct answer: 1) The planets in our Solar System orbit around the ___. a) Sun b) Moon c) Mars d) Earth 2) The Sun is the brightest star because ___. a) it is the closest star to Earth b) it has the most gases c) it is biggest star in the sky d) it is the hottest star 3)The planets travel around the Sun in an oval path called an ___. a) eggshell b) oddball c) orbit d) asteroid 4) A strong force called ___ pulls the planets toward the Sun. a) energy b) gravity c) rotation d) motion 5) Most of the planets are about the same size as the Sun. a) True b) False 6) The outer planets are made mostly of ___. a) rocks and iron b) water and minerals c) hydrogen, helium and ice d) dust particles 7) When a meteoroid is found on the Earth’s surface, it is called a ___. a) comet b) meteor c) asteroid d) meteorite 8) In the early 1600’s, an important invention was made that helped scientists learn much more about the Solar System. This invention was ___. a) the telescope b) a space ship c) Halley’s Comet d) a meteorite Answer the questions: 1) If we were flying high above the Earth, what would you see? 2) What is the Sun? 3) What is the Sun made of? 4) What are the smallest and the biggest planets? 5) Do all planets rotate at the same speed? 6) What are inner planets made of? 7) Does each planet have the same quantity of Moons? 8) What object is called “asteroid”? 9) Do many meteoroids fall to the Earth? 10) What does comet look like? 11) What is comet made of? 12) Why did people think the Earth was in the centre of space and that the sun and other stars orbited around it? Vocabulary Find words or phrases in the article that mean the following. You’ve been given the first letter to help you. 1 O___ is the path taken by an object moving around a larder object in space. 2 F ___ is the power of energy produced by one thing hitting another. 3 M___ is an object similar to a planet that goes around another planet. 4 T ___ is a piece of equipment shaped like a tube that you look through to make distant object look closer and larger. 5 A ___ is small chunks of rocks goes around the Sun, especially between Mars and Jupiter. Text 3B Our Solar System By Laura G. Smith If you look up the word "solar" in your dictionary, you'll find its basic definition reads something like: "of the sun," or "relating to the sun." System"is defined as: "a set of things or parts forming a whole." When you consider the meanings of these words, there is indication that the sun plays a major role among this group of celestial bodies we call the "solar system." The sun is, in fact, at the centre of this massive system. There are nine major planets and their satellites, asteroids, comets, dust and gases that are continually traveling around the sun. With a mass that is 750 times as great as that of all of the planets in the solar system combined, the sun has a strong gravitational pull that keeps the other objects in orbit around it. As the planets revolve around the sun, the sun revolves around the centre of the Milky Way Galaxy. The Milky Way, which has a circular shape, is made up of dust, gases, planets, and about 100 billion stars. The sun, planets, and other bodies and gases that make up our solar system are only a small speck in this huge galaxy! The nine planets of the solar system can be divided into two groups referred to as the inner planets (also called terrestrial planets) and the outer planets (or major planets). The inner planets; Mercury, Venus, Earth, and Mars, are small and are composed of mostly rock and iron. Jupiter, Saturn, Uranus, and Neptune make up the outer planets, which are much larger and consist mainly of hydrogen, helium and ice. Because Pluto is the farthest planet from Earth, astronomers know very little about it. Some believe it should not even be considered as one of the major planets. More than 120 natural satellites (also called moons) orbit these various planets in our solar system. Asteroids (also called planetoids) are small bodies that orbit the sun, mostly between Mars and Jupiter, in what is referred to as the Asteroid Belt or Main Belt. Astronomers first observed asteroids in the early 1800's with the aid of telescopes. There are more than 20,000 asteroids ranging in size from Ceres, which has a diameter of 623 miles, to bodies that are less than 1 mile in diameter. The Asteroid Belt also includes large amounts of dust that astronomers believe were created by collisions between asteroids. Small chunks of iron and rock that break away from colliding asteroids are called meteoroids. Many meteoroids fall to the earth's atmosphere, but most are burned up by friction before they reach the earth's surface. Meteoroids that fall through the atmosphere, appearing in the night as streaks of light, are called meteors or "shooting stars." Those that are found on the earth's surface are known as meteorites. As scientists have studied meteorites, they have learned valuable information about the ancient conditions of our solar system. The surfaces of Mercury, Mars, and several satellites of the planets (including the earth's moon) show signs of having been "attacked" by asteroids during the early history of the solar system. Some meteors and interplanetary dust (dust that is in between or near the planets) may come from comets. Comets generally have three parts: a solid nucleus or centre, which is often no bigger than a few miles across; a round coma, or head, that surrounds the nucleus and is made up of dust particles and frozen gases; and a long tail of dust and gases that escape from the head. Most comets orbit the sun near the outer edge of the solar system. When a comet is drawn closer to the sun, it releases its dust and gases displaying a spectacular, shining tail. The famously known Halley's Comet appears every 75 years. Its most recent appearance was in 1986. Solar wind is another part of the solar system. It is a very thin gas that streams outward constantly from the surface of the sun and through interplanetary space. The particles in solar wind travel past the earth at speeds of about 300 miles per second. This wind also shapes the tails of comets and leaves its particles in the lunar soil. Samples of these particles were brought back from the moon's surface by manned United States Apollo spacecraft. Since the invention of the telescope, man has greatly increased his knowledge of our solar system. It almost seems silly to realize that ancient astronomers once believed that the earth was the centre of the universe and that the sun and all of the other stars revolved around the earth! Little by little astronomers are solving mysteries about the universe. As more powerful tools and techniques are developed, astronomers will become even better equipped to satisfy our curiosity about the amazing stars and planets that decorate our sky. Choose the correct answer: 1) What holds the planets and other bodies of our Solar System in orbit around the sun? a) The gravitation pull of the planets b)The gravitation pull of the sun c) The rotation of the bodies d) The atmosphere 2) The Sun revolves around the a) Solar System b) Planets c) The universe d) Milky Way Galaxy 3) ___ is the farthest planet from the Sun. a) Pluto b) Mercury c) Mars c) Neptune 4) Small bodies that orbit the sun between Mars and Jupiter are called a) asteroids b) meteorites c) comets d) meteors 5) Meteors are often called a) shining stars b) shooting stars c) sparkling stars d) shrinking stars 6 )The word “interplanetary” means a) inside a planet b) in the universe c) between the planets d) collision of planets 7) Comets basically have three parts. They are a) ___ b) ___ c) ___ 8 ) Solar wind occurs as gusts of wind on Sun, similar to strong wind gusts on the Earth a) True b) Fasle Answer the questions: 1) What does the word “solar system" mean? 2) What is the mass of Sun? 3) What is the Milky Way made up? 4) How many groups the nine planets of the solar system can be divided into? 5) When do astronomers first observe asteroids? 6) Do all more than 20,000 asteroids have the same size? 7) How can you name small chunks of iron and rock that break away from colliding asteroids? 8) What information did scientists obtain having studies the meteorites? 9) What is happening when a comet is drawn closer to the sun? 10) What do you know about Halley's Comet? 11) How can you name a very thin gas that streams outward constantly from the surface of the sun and through interplanetary space? 12) At what speed does solar wind travel past the earth? 13) Why astronomers can satisfy our curiosity about the amazing stars and planets that decorate our sky?
Word Bank:
Our ___ consists of the sun, eight ___ and a dwarf planet (and their moons), an ___ belt, and many comets and meteors. The Sun is the ___ of our Solar System. The planets, their moons, the asteroids, comets, meteoroids and other rocks and gas all orbit the ___. The planets that orbit the sun are (in order from the Sun): ___, Venus, Earth, Mars, ___ (the biggest planet in our Solar System), Saturn (with large, orbiting rings), Uranus, Neptune, and Pluto (a dwarf planet). A belt of asteroids (many minor planets made of rock and metal) orbits between ___ and Jupiter. These objects all orbit the Sun in roughly circular orbits that lie in the same plane, called the ___ (___ is an exception to this; it has an elliptical orbit that is tilted over 17° from the ecliptic). The ___ planets (those planets that orbit close to the Sun) are quite different from the outer planets (those planets that orbit far from the Sun). The inner planets are Mercury, Venus, ___, and Mars. They are relatively small, composed mostly of ___, and have few or no moons. The outer planets are Jupiter, Saturn, Uranus, Neptune, and Pluto (a dwarf planet). They are mostly huge, mostly ___, ringed, and have many ___ (again, the exception is Pluto which is small, rocky, dwarf planet with one large moon and two tiny moons). |