54 The Solar System-Mid

The Solar System Written by David Dreier

《太阳系》大卫·德雷尔著

Introduction The solar system is our home in space. It's special to us because it's where we live. Understanding our solar system and how it formed might give us clues about other solar systems. Let's take an imaginary flight through the solar system. We'll start at the center: the Sun. As we move away from the Sun, we will pass many planets and other objects. One of those planets is our own Earth. All the objects in the solar system are circling the Sun. In this book, you will read about all parts of the solar system. Climb aboard! Let's begin our journey.

太阳系是我们的太空家园。 它对我们来说很特别，因为它是我们生活的地方。 了解我们的太阳系及其形成方式可能会给我们提供了解其他太阳系的线索。 让我们想象一次穿越太阳系的飞行。 我们将从中心开始:太阳。 当我们远离太阳时，我们将经过许多行星和其他物体。 其中一个行星就是我们的地球。 太阳系里所有的物体都在绕着太阳转。 在这本书中，你将读到太阳系的各个部分。 爬上!让我们开始我们的旅程。

The Sun The Sun is one of many many, stars in the universe. Stars are huge, fiery balls of gas. The Sun is made mostly of a gas called hydrogen. The Sun is medium-sized compared to other stars. It looks bigger because it is so much closer. The Sun is about 150 million kilometers (93 million mi.) from Earth. Other stars are trillions of kilometers away. Atoms of hydrogen in the center of the Sun are forced together by heat and pressure. They join to form a gas called helium. This process gives off huge amounts of energy and causes the Sun to be hot and bright. Temperatures in the Sun vary. The hottest part of the Sun is its center. The surface of the Sun is much cooler.

太阳太阳是宇宙中许许多多星星中的一颗。 恒星是巨大的、炽热的气体球。 太阳主要是由一种叫做氢的气体构成的。 与其他恒星相比，太阳是中等大小。 它看起来更大，因为它离我们很近。 太阳距离地球大约1.5亿公里(9300万英里)。 其他恒星在数万亿公里之外。 太阳中心的氢原子在热和压力的作用下聚集在一起。 它们结合在一起形成一种叫做氦的气体。 这一过程释放出巨大的能量，使太阳变得又热又亮。 太阳的温度是变化的。 太阳最热的部分是它的中心。 太阳表面的温度要低得多。

The Sun has nearly all of the matter in the solar system. The Sun's huge amount of matter gives it very strong gravity. Gravity is a force of attraction between all objects in the universe. Gravity keeps the planets orbiting the Sun. It also keeps 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

太阳几乎拥有太阳系中所有的物质。 太阳的大量物质赋予了它很强的引力。 万有引力是宇宙中所有物体之间的吸引力。 引力使行星绕太阳运行。 它还使卫星绕行星运行。 关于太阳的快速事实直径:139万公里(864万英里)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:质量是33.2万倍Wowser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，但太阳需要50亿年才能消耗掉这么多的氢

The Planets Our trip through the solar system will take us by eight planets. The number used to be nine. But one planet, Pluto, is no longer called a planet. Scientists place the planets into two groups. Mercury, Venus, Earth, and Mars are called the terrestrial (tuh-RES-tree-ul) planets. They have solid, rocky surfaces. Terrestrial means "like Earth." Saturn, Jupiter, Uranus, and Neptune are called gas giants. They do not have a solid surface. You wouldn't be able to breathe the air on these planets. 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。 但是有一颗行星，冥王星，不再被称为行星。 科学家将行星分为两类。 水星、金星、地球和火星被称为类地行星(tuh-RES-tree-ul)。 它们有坚固的岩石表面。 Terrestrial意为“像地球一样的”。 土星、木星、天王星和海王星被称为气体巨星。 它们没有固体表面。 在这些星球上，你无法呼吸空气。 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 see as we leave the Sun is Mercury. It is small and covered with craters. Mercury looks a lot like Earth's Moon. And like the Moon, it has no air. If you were standing on 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 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

离开太阳后我们看到的第一颗行星是水星。 它很小，布满了陨石坑。 水星看起来很像地球的月球。 和月球一样，它也没有空气。 如果你站在水星上，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