55 The Solar System-High

The Solar System Written by David Dreier

《太阳系》大卫·德雷尔著

Introduction Earth is our home, and the solar system is our local neighborhood in the universe. Our solar system is just one of many, near the outer edge of just one of billions of galaxies— huge rotating masses of stars— in the universe. But it's special to us because it's where we live. Understanding our own solar system and how it formed might even give us clues about solar systems elsewhere in the universe. Let's take an imaginary flight from the center of our solar system to its outer edges. We start at the Sun, the center of the solar system. As we move away from the Sun and travel to the very edges of the solar system, we will pass many objects of varying sizes and shapes. All of them, just like Earth, are circling the Sun. Climb aboard our fantasy spaceship! Let's begin our journey.

地球是我们的家，太阳系是我们在宇宙中的邻居。 我们的太阳系只是众多星系中的一个，它位于宇宙中数十亿个星系(巨大的旋转恒星质量)之一的外缘。 但它对我们来说很特别，因为它是我们生活的地方。 了解我们自己的太阳系及其形成方式甚至可能为我们提供宇宙其他地方太阳系的线索。 让我们假想一次飞行，从太阳系的中心飞到它的外缘。 我们从太阳系的中心太阳开始。 当我们离开太阳，到达太阳系的边缘时，我们会经过许多大小和形状各异的物体。 它们都像地球一样绕着太阳转。 登上我们的梦幻飞船!让我们开始我们的旅程。

The Sun The Sun is one of countless stars in the universe. Stars are huge, fiery balls of gas. The Sun is medium-sized compared to other stars— it only looks larger because it is much, much closer to us. The Sun is about 150 million kilometers (93 million mi.) from Earth, while other stars are trillions of kilometers away. The Sun— like other bright stars— is made mostly of hydrogen gas. Hydrogen is the lightest element in the universe. Atoms of hydrogen in the Sun's center are forced together by extreme heat and pressure. In this joining process, called fusion, four hydrogen atoms produce one atom of helium. Fusion releases huge amounts of energy that cause the Sun to be extremely hot and bright. Temperatures in the Sun vary greatly. The hottest part of the Sun is its core. The surface of the Sun is much cooler. As hydrogen atoms form helium, the supply of hydrogen decreases.

太阳太阳是宇宙中无数恒星中的一颗。 恒星是巨大的、炽热的气体球。 与其他恒星相比，太阳是中等大小的——它看起来更大，只是因为它离我们非常非常近。 太阳距离地球大约1.5亿公里(9300万英里)，而其他恒星距离地球数万亿公里。 太阳和其他明亮的恒星一样，主要是由氢气构成的。 氢是宇宙中最轻的元素。 太阳中心的氢原子在极端高温和高压的作用下聚集在一起。 在这个被称为聚变的结合过程中，四个氢原子产生一个氦原子。 核聚变释放出巨大的能量，使太阳变得非常热和明亮。 太阳的温度变化很大。 太阳最热的部分是它的核心。 太阳表面的温度要低得多。 当氢原子形成氦时，氢的供应就减少了。

The Sun is by far the most massive object in our solar system. It contains more than 99 percent of all the mass— quantity of matter— in the solar system. The Sun's tremendous mass gives it extremely strong gravity. Gravity is a force of attraction between all objects in the universe. It is gravity that keeps planets orbiting the Sun, and moons orbiting planets. Fast Facts About the Sun Diameter: 1.39 million kilometers (864,000 mi.) Temperature: Core: about 15 million ºC (27 million ºF) Surface: about 5,500ºC (10,000ºF) Corona: more than 1 million ºC (1.8 million ºF) Mass, compared with Earth: 332,000 times as massive Wowser! Over time, the Sun's supply of hydrogen will almost run out. The Sun will then begin to cool down. But it will take 5 billion years for the Sun to use up that much hydrogen!

到目前为止，太阳是太阳系中质量最大的物体。 它包含了太阳系中99%以上的质量(物质的数量)。 太阳巨大的质量赋予了它极强的引力。 万有引力是宇宙中所有物体之间的吸引力。 是引力使行星绕太阳运行，卫星绕行星运行。 关于太阳的快速事实直径:139万公里(86.4万英里)温度:核心:约1500万ºC(2700万ºF)表面:约5500ºC(10,000ºF)日冕:超过100万ºC(180万ºF)质量，与地球相比:是Wowser质量的33.2万倍!随着时间的推移，太阳的氢供应将几乎耗尽。 太阳将开始冷却下来。 但太阳需要50亿年才能消耗掉这么多氢!

The Planets Our trip through the solar system will take us by eight planets. The number used to be nine. But in 2006, the most distant planet, Pluto, lost its standing as a planet. Scientists place the planets into two groups. One group is the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. These planets are called the terrestrial (tuh-RES-tree-ul) planets because they have solid, rocky surfaces. The word terrestrial means "like Earth." The outer four planets— Saturn, Jupiter, Uranus, and Neptune— are called gas giants. These planets are big balls of gas and do not have a solid surface. Do You Know? Here's a memory aid to remember the order of the planets from the Sun (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune): My Very Educated Mother Just Showed Us Neptune.

行星我们的太阳系之旅将经过8个行星。 这个数字过去是9。 但在2006年，最遥远的行星冥王星失去了行星的地位。 科学家将行星分为两类。 一组是离太阳最近的四颗行星:水星、金星、地球和火星。 这些行星被称为类地行星(tuh-RES-tree-ul)，因为它们有坚固的岩石表面。 “terrestrial”这个词的意思是“像地球一样”。 外层的四颗行星——土星、木星、天王星和海王星——被称为气体巨星。 这些行星是巨大的气体球，没有固体表面。 你知道吗?这里有一个记忆帮助记住行星的顺序从太阳(水星，金星，地球，火星，木星，土星，天王星，海王星):我非常有教养的母亲刚刚给我们看了海王星。

The Terrestrial Planets The first planet we encounter as we leave the Sun is Mercury, a small, barren planet that is covered with craters. Craters are scars on the surface of a planet that form when meteorites or other objects strike it. Mercury looks a lot like Earth's Moon. And like the Moon it has no atmosphere. If you were standing on the surface of Mercury, the Sun would look three times larger than it does on Earth. When the Sun is overhead on Mercury, the temperature rises to about 430°C (800°F). After sunset, it drops down to about -170°C (-280°F). Fast Facts About Mercury Diameter: 4,879 kilometers (3,032 mi.) Average distance from the Sun: 58 million kilometers (36 million mi.) Period of rotation (one turn on axis): 59 Earth days Period of revolution (one orbit around Sun): 88 Earth days Number of moons: 0

当我们离开太阳时，我们遇到的第一颗行星是水星，这是一颗覆盖着陨石坑的贫瘠的小行星。 陨石坑是行星表面的伤疤，是由陨石或其他物体撞击形成的。 水星看起来很像地球的月球。 和月球一样，它也没有大气层。 如果你站在水星表面，太阳看起来会比地球上大三倍。 当太阳在水星上方时，温度上升到约430°C(800°F)。 日落后，气温下降到-170°C(-280°F)。 关于水星的快速事实直径:4879公里(3032英里)平均距离太阳:5800万公里(3600万英里)自转周期(轴上一圈):59地球日公转周期(绕太阳一圈):88地球日月球数:0