53 The Solar System-Low

THE SOLAR SYSTEM Written by David Dreier

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. Let's take an imaginary flight through the solar system. We'll start at the center, with the Sun. As we move away from the Sun, we will pass many planets. One of those planets is our own Earth. Earth and the other planets all circle the Sun. 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。 让我们想象一次穿越太阳系的飞行。 我们从中心开始，从太阳开始。 当我们远离太阳时，我们将经过许多行星。 其中一个行星就是我们的地球。 地球和其他行星都绕着太阳转。 爬上!让我们开始我们的旅程。

The Sun The Sun is one of many stars in space. Stars are huge, fiery balls of gas. The Sun is made mostly of a gas called hydrogen. The Sun looks big and bright because it is fairly close to us. Other stars are much much farther away. That's why they're just little specks of light. Atoms of hydrogen in the center of the Sun are forced together. They turn into a gas called helium. This process gives off huge amounts of energy. It causes the Sun to be hot and bright.

太阳太阳是太空中众多恒星中的一颗。 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。 太阳看起来又大又亮，因为它离我们相当近。 其他恒星要远得多。 这就是为什么它们只是小光点。 太阳中心的氢原子被迫聚在一起。 它们会变成一种叫做氦气的气体。 这个过程释放出巨大的能量。 它使太阳又热又亮。

The Sun's huge size gives it very strong gravity. Gravity is a force that pulls objects together. Gravity keeps the planets orbiting the Sun. 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 hydrogen will almost run out. The Sun will begin to cool down. But it will take 5 billion years for that to happen!

太阳的巨大体积赋予了它很强的引力。 重力是一种把物体拉在一起的力。 引力使行星绕太阳运行。 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，太阳的氢几乎会耗尽。 太阳将开始冷却。 但这需要50亿年才能实现!

The Planets Our trip through the solar system will take us by eight planets. Scientists place the planets into two groups. One group has Mercury, Venus, Earth, and Mars. They all have a solid surface. The outer four planets are Saturn, Jupiter, Uranus, and Neptune. These planets 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。 科学家将行星分为两类。 一组是水星、金星、地球和火星。 它们都有固体表面。 最外层的四颗行星是土星、木星、天王星和海王星。 这些行星被称为气体巨星。 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 Inner Planets The first planet we see after leaving the Sun is Mercury. It is a small planet covered with craters, like our Moon. And like the Moon, it has no air. On Mercury, the Sun looks 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

我们离开太阳后看到的第一颗行星是水星。 它是一颗布满陨石坑的小行星，就像我们的月球一样。 和月球一样，它也没有空气。 在水星上，太阳看起来比地球上大三倍。 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)。 关于水星直径4,879公里(3,032英里)距离太阳的平均距离:5,800万公里(3,600万英里)自转周期(轴转一圈):59地球日公转周期绕太阳一周88个地球日月球数:0