月亮的黑暗面在哪里？

The descriptor "dark side" is problematic. It seems to suggest that shadows perpetually cloak the surface of one side of themoon。很容易想象光线和黑暗之间的分裂界线，并且通过越过这条线，您可以进入月球侧面，我们永远不会从地球。But that's simply not true.

虽然在任何特定时间都有月球的某些部分是黑暗的，但它并不总是同一部分。那是因为像地球一样，月亮有白天和夜间。因此，如果您要在月球上建立营地并保持原样，您最终会看到太阳升起。你会白天和黑夜。

Since the dark side of the moon shifts as the lunar day progresses, it's more accurate to say that the moon has a一天和夜面，就像地球一样。一天的一面是目前接收阳光的一面，而夜间则远离sun。What does this have to do with the side we see when we look at the moon from Earth? That's where things can get confusing. The side of the moon we see is sometimes the day side, and sometimes the night side. It all depends on when during the lunar day we look at the moon.

一个更准确描述我们看到的月球一侧的术语是近侧。近侧对面的一侧是远端。The near side will always face toward us, and the far side will always face away. This is true even on the opposite side of the Earth. If you were to fly from America to Australia just to get a look at the moon down there, you'd see the same features you're familiar with back home.

近侧和月球的远端都有一天又一个晚上。两者都在月球围绕地球的某些点接收阳光。我们只是看不到月球的另一侧，即使太阳在阳光下闪耀，因为远端总是远离我们。

那么，为什么我们只看到地球上的月球一侧，而月球的阶段与之有什么关系？继续阅读以找出答案。

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It takes about 29 days for themoon使一个完整的轨道围绕地球。这也是月球围绕其轴旋转需要多长时间的时间。因为月亮的旋转和轨道需要相同的时间，所以无论何时看它，我们总是看到月亮的相同面孔。听起来有些混乱，但是以下动画应该有助于清除内容。

如果月亮不旋转，我们将能够看到其表面的所有侧面。同样，如果月亮的旋转速度更快或较慢，我们最终会瞥见整个月球。那么，为什么月亮每次绕地球绕一次旋转一次呢？

简短的答案是重力。The pull on the moon from the Earth has slowed the moon's rotation down to its current speed. Its rotation is locked with the time it takes to orbit the Earth.

Interestingly, the moon is doing the same thing to the Earth. Ever feel like the days are getting longer? They are. But the change is so gradual you'd never notice it. Still, in a few billion years, the Earth's rotation will match the time it takes the moon to orbit the Earth. By that time, the moon and Earth will have drifted apart from each other a bit, which means it will take a little longer for the moon to travel around the Earth -- to the tune of about 40 days or so. That means that in the future, one Earth day will equal 40 of our current Earth days, or about 960 hours [source:space.com]。

Once the Earth's rotation matches the time it takes for the moon to orbit the Earth, the same side of Earth will face the moon all the time. Does that mean that if you were to travel through time to the future, travel to the right spot on Earth and stare up at the sky you'd always be able to see the moon? The answer is no, and it has to do with the月相。

关于月亮的一个普遍误解是，当地球封锁时，新月发生lightfrom thesun, casting the moon into shadow. In fact, during a new moon the moon is between the sun and the Earth. Imagine that you're in a room that has only one light source shining into it from one side. Someone walks between you and the light source. You wouldn't be able to make out any details, but you could see the person in silhouette. That's exactly what a new moon is.

A full moon is when the Earth is between the moon and the sun. Going back to our example, imagine that you have your back to a light source and someone is standing in front of you. You'd be able to see that person clearly. That's the same as a full moon.

无论是满月还是新月，您仍在看月球的同一侧 - 近一侧。在新月期间，您正在农历夜间看着近一侧。有了满月，这是近侧的中午版本。

因此，没有月球的永久黑暗面，但是遥远的一面仍然对我们来说是一个谜。由于月亮的散装将阻止往返于地球的无线电信号，因此工程师提出一种更大程度地探索远处的方法可能是几年了。我们甚至可能开始看到NASAand other organizations erect radio relay towers on the moon's surface to make such exploration possible. Until then, we'll have to go loony over the side that faces us.

想了解有关月球和相关主题的更多信息吗？Moonwalk到下一页上的链接。