The Smithsonian Institution says they were the first ever retrieved from another planetary body.

史密森尼学会天文台说，这是有史以来第一次从另一个行星体中找到它们。

These disks are the remnants of planetary formation.

这些圆盘是行星形成的剩余物质.

This fixed everything, including those aggravating planetary motions.

这一点修正了一切，包括那些复杂的行星运动。

This object is what we call a planetary nebula.

这个物体就是我们所说的行星状星云。

It's going to some other planetary system.

而是去了其它星系。

By the time we're ready to settle even the nearest other planetary systems.

到那，我们准备好移民到即使是最近的星球的候。

We who cannot even put our own planetary home in order.

我们，尚不能整治自己的星球的我们。

And we see all the stars surrounded by completed planetary systems.

我们也知道所有恒星都由完全形成的行星系统环绕。

And from there, be able to map out a timeline of planetary development.

接着我们就能描绘出行星变的整个过程。

And so, this was NASA's first ever planetary defense test mission.

这是NASA的第一次行星防御测试任务。

So some planetary systems are aligned just so.

所以有些行星系就是这样排列的。

However, most planetary scientists still do, which is why we're using that terminology here.

但是，绝大部分行星科学家还是认为冥王星是行星，这就是我们使用这个术语的原因。

And that creates an interesting problem in understanding planetary evolution.

引出了一个关于行星化的有趣问题。

Jay Melosh studies planetary impacts at Purdue University.

在普渡大学研究行星撞击的杰伊·梅洛什说到。

Mann added that he believes this pattern " is connected to human-caused planetary warming" .

曼恩补充说，他相信这种模式" 与类造成的地球变暖有关" 。

Unfortunately, Copernicus's model was also pretty top-heavy, and had a hard time predicting planetary motions.

不幸的是，哥白尼的模型仍然非常复杂，对行星运动的预测也不准。

That planetary heat causes all of this chaotic change, which we could call climate change.

行星的热量导致了所有这些混乱的变化，我们可以称之为气候变化。

So planetary astronomer, Heidi Hammel, submits a proposal to NASA.

行星天文学家海蒂∙海莫向NASA递交了一项建议。

But the question still remains, why aren't the planetary orbits perfectly circular?

但问题仍然存在，为什么行星的轨道不是完美的圆形？

Charles El Mir is a mechanical engineer who studies planetary science at Johns Hopkins University.

约翰·霍普金斯大学研究行星科学的机械工程师查尔斯·埃尔米尔说到。