Planets don't like each other, because they're gravitationally tugging each other.

行各自不喜欢对，行各不相同取决于各自的引力。

There are nine planets in the solar system.

在太阳系中有九行。

I'm the fourth largest planet in our system.

我是太阳系第四行。

It's the glue that holds the planets in orbit around the sun.

它让九行围绕着太阳旋转。

And was the 9th planet from the Sun.

我是太阳系第九行。

What say we finish ourselves an eight-planet solar system?

我们一起把那8行太阳系模型做完吧？

I'm the 2nd largest planet in our solar system.

我是太阳系中第二行。

So what does Tyson maintain is so wrong with Pluto?

泰森为什么要把冥王从九行中移除？

Venus is the sixth largest planet in the Solar System.

型上，金是太阳系中第6行。

Well, a crater ridge on Vesta, a large asteroid, is around 19 kilometers high.

嗯，行灶神上的陨石坑脊约有 19 公里高。

It's the second largest planet, but ironically the least dense.

它是太阳系第二行，却也是密度最小的一个。

Callisto orbits Jupiter farthest out of the four biggies, almost two million km away.

在四个行中，木卫四的公转轨道离木最远，约达200万千米。

Some people wanted Eris recognized as the tenth planet.

有人希望将阋神命名为第十行。

Juno's goal is to investigate what the giant planet is made from and how it's put together.

“朱诺”的目的是调查这颗行的构成成分和形式。

That's a pretty big gap between a big planet and a small star.

这就是一颗行和一颗小恒之间相当的差距。

So what's the difference between a small brown dwarf and a really big planet?

那么一颗小褐矮和一颗行有什么区别呢？

It was launched on January 19, 2006, while Pluto was still considered the ninth planet.

新视野号于2006年1月19日发射，当时冥王还被认为是第九行。

When Pluto was discovered in 1930, it was named the ninth planet of the solar system.

1930年，冥王被发现之时，它被列为太阳系第九行。

A ninth massive planet was predicted, leading to a grand search that resulted in the discovery of Pluto.

科学家曾预测第九行会出现，从而引发了一场范围的搜寻，最终发现了冥王。

A large planet with hints of cloud formation.

一颗有云形成迹象的行。