国家地理 月亮的故事（在线收听）

Whether it was believed to have been a big ball of cheese, home to the men in the moon, or possess the power to turn people into werewolves, the moon has been a perpetual source of wonder from ancient time to today. Just one quarter the size of the Earth, the moon is small compared to other more spectacular bodies in the universe. But since it's only 240 thousand miles away, a relatively short distance when compared with the vastness of space, nothing looms larger in the night sky.

有人认为月亮是一个大奶酪球，有人认为月亮上有月球人，还有人认为月亮可以将人类变成狼人，从古至今，月亮一直非常奇妙。月球只有地球的四分之一大小，与宇宙中其他更壮观的天体相比，它是很小的。但由于它距离地球只有24万英里，与浩瀚的太空相比，这是一段相对较短的距离，因此在夜空中没有什么比它更大了。

Many scientists believe the moon formed about 4.6 billion years ago. One theory is that a huge asteroid struck earth with such force that rock and debris were shot into orbit around the planet like the rings of Saturn. Over time this cloud of fragments came together to form the moon. Since it has little of any atmosphere to protect it, the moon has been and continues to be bombarded by space debris. The evidence appears all over its dusty surface. Its entire surface is pocked with tens of thousands of craters. It wasn't until Galileo pointed a telescope at moon in 1609 that we got the first close look at its features.

许多科学家认为月球是46亿年前形成的。有一种理论认为，一颗巨大的小行星撞击地球的力量很大，导致岩石和碎片像进入土星环一样的环绕地球的轨道。随着时间的推移，这一大团碎片聚集在一起形成了月亮。由于几乎没有任何大气层来保护它，月球始终受到太空碎片的撞击。它尘土飞扬的表面就是最好的证明。它的整个表面布满了成千上万个火山口。直到1609年伽利略用望远镜对准月球，我们才第一次近距离观察到它的特征。

The moon orbits the earth like the earth orbits the sun. Since the moon doesn't shine on its own but only reflects light from the sun, we see more or less of it during its monthly revolution depending on its position. We call these varying views--phases. When the moon is on the far side of the earth away from the sun, the moon is fully illuminated or full. As the moon travels around the earth, we can only see the sunlight falling on part of it resulting in crescent moons and half moons. When the moon is directly between the earth and the sun, light falls on the far side of the moon, blocked from earth's view, the moon is dark or new. It takes about 29 days for the moon to complete its cycle. On rare occasions a full moon passes through the earth's shadow and the sun's light is blocked. This is called a total lunar eclipse. The moon has quite an effect on our planet. As earth turns the moon's gravity tugs on our oceans creating the tides. The tidal forces have curved our planet's coastlines, buoyed its polar icecaps and influenced the rhythm of life. Our nearest celestial neighbor is a lot more than a beautiful view.

月球绕地球运行，就像地球绕太阳运行一样。由于月球本身并不发光，只反射太阳的光，我们可以在它每月公转过程中的不同位置看到它大大小小的样子。我们把这些看到不同的样子称为月相。当月球在远离太阳的地球的另一边时，月球就会被完全照亮或变成满月。月球绕地球运行时，我们只能看到阳光落在它的一部分上，出现新月和半月。当月球位于地球和太阳中间时，光线落在月球的另一侧，挡住了地球的视线，月球就全暗了或是新月。月球完成一个周期大约需要29天。极少数的时候，整个月亮进入地球的阴影，太阳的光线会被挡住。这被称为月全食。月球对我们的星球有相当大的影响。当地球转动时，海洋会受到月球的引力，形成潮汐。潮汐力弯曲了地球的海岸线，使极地冰盖漂浮起来，影响了生活节奏。我们天体近邻不仅仅是美丽的景色。