NASA撞击小行星任务

NASA is going to try something it has never done before.

美国国家航空航天局（NASA ）将尝试一件以前从未做过的事情。

It's going to attempt to move an asteroid.

NASA将试图移动一颗小行星。

It's part of a mission to test technologies humanity may someday need to keep a space rock from striking our planet.

这是一项测试技术任务的一部分，人类可能有一天会需要这些技术来防止太空岩石撞击我们的星球。

Just to be clear, they are not trying to move this asteroid because it's headed towards Earth, right?

澄清一下，他们试图移动这颗小行星并不是因为它朝着地球前进，对吧？

Right. I mean, we have enough problems.

是的。我是说，我们的问题已经够多了。

So yeah, the - an asteroid's the last thing we need.

小行星是我们最不需要的东西。

But this is passing close to Earth. It's not on a collision course.

但这颗小行星离地球很近。它并没有处于碰撞的轨道上。

Still, this mission is going to demonstrate how you might deflect a planet-killing asteroid.

不过，这次任务将演示如何使毁灭地球的小行星偏离轨道。

Tom Statler is a NASA scientist on the mission. And here's what he said at a briefing last week.

汤姆·斯塔特勒是此次NASA任务的科学家。这是他在上周的新闻发布会上发表的言论。

We're doing this test when we don't need to on an asteroid that isn't a danger just in case we ever do need to and we discover an asteroid that is a danger.

我们在不需要对一颗不构成危险的小行星进行测试的情况下进行这项测试，以防我们真的发现了一颗危险的小行星，需要这么做。

OK, practice. This is practice. That makes me feel better.

好的, 演习。这是演习。这让我感觉好多了。

So explain how this practice run's going to work.

那就解释一下这次演习是怎么进行的。

Sure. So this thing's called the Double Asteroid Redirection Test - or DART for short. And it's all right there in the name.

好的。这个项目被称为“双小行星重定向测试”，简称DART。这都写在名字里了。

The target is actually two asteroids, a big one called Didymos and a second smaller one that's orbiting the big one. That one's called Dimorphos.

目标实际上是两颗小行星，一颗大的叫做“迪迪莫斯”，另一颗小的绕着大的旋转。小的叫做“迪莫弗斯”。

So the spacecraft is going to try and slam into that little asteroid at more than 14,000 miles per hour.

这艘航天器将尝试以超过14000英里每小时的速度撞击那颗小行星。

And the hope is that that's going to nudge or redirect, as the cool kids call it, the asteroid just a tiny, tiny amount.

我们的希望是，这将轻推移动小行星、重新改变小行星方向，就像孩子们说的那样，这颗小行星只需要改变一点。

The nudge should change the time it takes the little asteroid to go around the big one, the time of a single orbit.

这一推动应该会改变那颗较小的小行星绕较大的小行星一圈所需的时间，即绕轨单圈所需的时间。

Astronomers on Earth are going to attempt to measure that change.

地球上的天文学家将努力测量这种变化。

And that will let them know whether this thing had the desired effect.

这将会让他们了解这次撞击是否达到了预期的效果。

OK. You say nudge. So this is not like in the movies, where they try to blow the asteroid up?

好。你说的推动。这和电影里不一样，电影里是想把小行星炸飞?

Right. Yeah. I mean, in fact, the whole nuking an asteroid thing is actually pretty risky, it turns out...Because you might end up with a lot of asteroid parts headed in the same direction.

是的。我的意思是，事实上，用核弹摧毁小行星实际上是相当危险的，事实证明了……因为最后可能会有很多小行星碎片朝同一个方向移动。

So you might end up with two big chunks instead of one.

所以你可能会得到两大块小行星碎片，而非一块。

Right.

是的。

So NASA thinks these little shoves are actually the way to go.

所以NASA认为这些小小的推力是可行的。

Now, obviously, if this were a planet-killer, this spacecraft would be too small.

现在，很明显，如果这是一个行星摧毁器，那这个航天器也太小了。

NASA might have to build a bigger version.

NASA可能要造一个更大版本的航天器。

Or they might have to build a bunch of little ones to give several pushes over a period of time.

或者，他们可能不得不建造一堆小的航天器，以在一段时间内提供数次推动。

But the thing to remember is space is really big.

但要记住的是，太空是非常浩瀚的。

So it may not take all that much to move an asteroid out of Earth's path.

因此，把一颗小行星移出地球的轨道可能并不需要付出那么多。

So what are you going to be watching for specifically in this exercise today?

在今天的演练中你们要特别注意什么?

Well, the spacecraft's actually going to be livestreaming as it approaches its target.

航天器在接近目标的过程中会进行直播。

So we should see the asteroid getting bigger and bigger.

所以我们应该会看到小行星变得越来越大。

It's steering itself using software that was developed for missile defense.

航天器会利用导弹防御系统开发的软件控制方向盘。

And hopefully, we're going to see it grow right up to the last minute before impact.

希望我们能看到航天器一直行驶到撞击前的最后一分钟。

And Statler says this test is going to be a really important proof of concept.

斯塔特勒称这个测试将是一个非常重要的概念证明。

At the end of the day, the real question is, how effectively did we move the asteroid?

到头来，真正的问题是，我们如何才能有效地移动小行星?

And can this technique of kinetic impact be used in the future if we ever needed to?

如果将来有需要，动能撞击的技术还能被使用吗?

But scientists say it could be days or even weeks before they know for sure how it went.

但科学家表示，他们可能需要几天甚至几周的时间才能确定事情的进展。