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

其实地球在转的同时也太阳公转。

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

尽管木星转速度很快，但它太阳公转一周大约需要12年。

What is the fastest spinning planet in our solar system?

太阳转最快的行星是哪颗？

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

我们经常看到月亮，是因为地球转速度快。

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

当一颗行星离它所的恒星近时，它的转就会固定。

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

因为转的方向不同于太阳所有其他行星。

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

这和行星转的速度有关。

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

地球转一周，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，那是我转一圈的时间。

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

当地球转时，海平面保持不变。

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

金星转一圈需要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行星转的方向相反。

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.

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 公里的速度转。

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

天体的行星和它们的卫星公转和转的运动，都是从右向左转。