月亮

Patterns of the motion of the Sun, Moon, and stars in the sky can be observed, described, and predicted.

::太阳、月亮和星星在天空中的运动模式可以被观察、描述和预测。

Look up and what do you see?

During the day you see the Sun.

It glows bright in the daytime sky.

At night, you will see the twinkling of tiny stars.

::抬头看，你看到了什么？白天你可以看到太阳。它在白天的天空中闪闪发光。在晚上，你会看到闪烁的小星星。

The Sun and the stars have a regular pattern.

The Sun can be seen during the day, the stars at night.

What about the Moon?

What patterns does it have?

::太阳和星星有一个规则的模式。白天可以看到太阳，晚上可以看到星星。月球呢？它有什么模式？

The Moon moves across the sky just like the Sun.

It moves across the sky just like the stars.

Unlike the Sun and stars, the way we see the Moon changes.

::月亮像太阳一样在天空中运行。它像星星一样在天空中移动。与太阳和恒星不同，我们看到月球的方式是变化的。

On some nights, you can see a big Moon hanging in the

night sky.

On other nights, only a part of the Moon can be seen.

::在一些夜晚，你可以看到一个大月亮挂在夜空中。在其他夜晚，只能看到月亮的一部分。

The Moon really does not change shape.

The change in the way you see the Moon is all part of

its pattern.

The Moon repeats its pattern every 28 days.

::月球确实不会改变形状。你看到月亮的方式的变化都是它模式的一部分。月球每28天循环一次。

You see the Moon full one night.

About seven days later, the Moon looks different.

No, it really has not changed shape.

It changes because it changes positions as it moves around

the Earth.

::有一天晚上你看到满月。大约七天后，月球看起来不一样了。不，它真的没有改变形状。它的变化是因为它在绕地球运动时改变了位置。

The half of the Moon that faces the Sun is always bright.

What changes is not how much is lit.

What changes is what part of the Moon we can see

from Earth.

::月亮面向太阳的那一半总是明亮的。变化的不是光照的多少，而是我们从地球上能看到月球的哪一部分。

Sometimes we cannot see the Moon.

We call this part of the pattern a new Moon.

Even then, half the Moon is lit by the Sun.

::有时我们看不到月亮。我们把这部分图案称为新月。即便如此，月球的一半仍被太阳照亮。

The Moon makes Earth’s oceans rise and fall.

The Moon pulls on the Earth with its gravity.

The Sun also plays a role.

The Sun has gravity too and pulls on the Earth.

This regular rise and fall is called the tide.

::月球使地球的海洋上升和下降。月球用它的引力拉着地球。太阳也起到了一定作用。太阳也有引力，对地球有吸引力。这种规律的涨落就叫做潮汐。

As the Earth rotates, gravity pulls in different places.

As a result, the water on Earth goes up and down.

The Moon has patterns and also causes patterns.

::地球自转时，引力会吸引不同的地方。因此，地球上的水上下波动。月亮有规律，也造成规律。