Well the earth is rotating while simultaneously revolving around the sun.

其实地球在自转的同时也绕太阳公转。

Though it spins quickly, Jupiter's orbit around the sun takes about 12 years.

尽管木自转速度很快，但它绕太阳公转一周大约需要12年。

What is the fastest spinning planet in our solar system?

太阳系中自转最快的是哪颗？

We can see it more often than that because of how fast the Earth rotates.

我们经常看到亮，是因为地球自转速度快。

When a planet is that close to its star, its rotation becomes locked.

当一颗离它所环绕的恒近时，它的自转就会固定。

So it spins backwards compared to the direction of spin of all the other planets.

因为自转的方向不同于太阳系中所有其他。

The planet's rotation rate has something to do with it.

这和自转的速度有关。

One turn on the Earth's axis takes 24 hours — that's what makes one day.

地球自转一周，需要24小时也就是一天。

Some spin with periods many seconds or even minutes long.

它们有些自转的周期仅有几秒甚至几分钟。

Or maybe it had trouble keeping up with the ground spinning beneath it?

或者可是它没跟上地球的自转？

24 hours makes one day that's just one time that I'm spun.

我的一天是 24 小时，那是我自转一圈的时间。

When the Earth spins on its axis, ocean levels stay the same.

当地球自转时，海平面保持不变。

It takes 243 Earth days for Venus to complete one full rotation.

金自转一圈需要243个地球日。

You see, Earth's spin on its axis gradually slows down over time.

你看，地球沿地轴自转的速度随时间而逐渐减慢。

That means they orbit in the opposite direction that the planet spins in.

这意味着它们的轨道方向与自转的方向相反。

Over long time scales, Earth's rotation is actually slowing down.

从长期来看，地球的自转实际上正在减慢。

Not to mention, the Earth's spin may increase, making days only hours long.

更不用说地球自转的速度也将加快，一天可只有几个小时。

The speed of this rotation is what defines a day.

自转的速度决定了一天的长度。

At the Equator, Earth spins at a speed of 1670 kilometers per hour.

在赤道，地球以每小时 1670 公里的速度自转。

In their rotational and orbital movements, stars and their satellites go from right to left.

天体的和它们的卫公转和自转的运动，都是从右向左转。