如何阻止天外杀手撞击地球？(中)

So to look at how amazing this is, let’s take a look at the size of Dimorphos. How big is it, exactly?And how far away was it?[qh]

为了看看这次撞击有多神奇，我们来看看“迪莫弗斯”的大小。这颗小行星到底有多大? 距离有多远?[qh]

So Dimorphos is about as big and heavy as the Great Pyramid. It’s also about as big as the Roman Colosseum.[qh]

“迪莫弗斯”与大金字塔一样大，一样重。与罗马斗兽场也一样大。[qh]

Okay, that’s pretty big.[qh]

好吧，体积相当大。[qh]

But for those of us steeped in modernity, I like just to say it's about twice the size of a standard football field, and it weighed an estimated 11 billion pounds.[qh]

不过，对于我们这些沉浸在现代生活中的人来说，我会说，“迪莫弗斯”大约是标准足球场的两个大，其重量估计有110亿磅。[qh]

Whereas DART is just a 1,260-pound spacecraft—about the size and weight of a dairy cow. [qh]

而DART（航天器）只是一个1260磅的宇宙飞船——大约是一头奶牛的大小和重量。[qh]

The fact that DART made a dent at all really comes down to its high-velocity impact, which we already said was 14,000 miles per hour. [qh]

DART砸出的坑实际上是由其高速撞击引起的，我们提到过，时速为每小时14000英里。[qh]

And all this took place after a deep-space voyage to the impact point, more than seven million miles from Earth.[qh]

此前，一次深空航行驶向距离地球700多万英里的撞击点。[qh]

So, that’s like a dairy cow smashing into a great pyramid?[qh]

这就像一头奶牛撞进了一个大金字塔中?[qh]

Basically, it gets messy.[qh]

基本上，一片狼藉。[qh]

Huh. Well, let’s get back to the science. [qh]

嗯。好吧，让我们回归科学。[qh]

We know that getting more details is helping astronomers understand why this crash was so successful. [qh]

我们知道，获得更多的细节可以帮助天文学家理解这次撞击如此成功的原因。[qh]

What are some of the new details around the impact that have been found? And what surprised scientists? What was NASA’s original goal here?[qh]

关于这次撞击，我们发现了哪些新的细节? 是什么令科学家们感到惊讶？美国宇航局最初的目标是什么?[qh]

That’s a great question Tulika. And the answer was that the surprise was how well it worked. [qh]

这个问题问得好，图利卡。答案是，令人惊讶之处是撞击效果竟如此之好。[qh]

NASA’s official criterion for success was shifting Dimorphos’s orbit by just 73 seconds.[qh]

美国宇航局的官方成功标准是将“迪莫弗斯”的轨道改变73秒。[qh]

Initial predictions – if it was actually a billiard ball, for instance, all solid material – predictions were that maybe DART would nudge it off by about 7 minutes. Instead we got 33, 33 minutes![qh]

假设“迪莫弗斯”是一个台球，那么它完全由固体物质组成，最初预测DART可能推动“迪莫弗斯”，使其快大约7分钟。实际上快了33分钟![qh]

Yeah! And the difference is due to Dimorphos not being a billiard ball at all. [qh]

对! 造成这种差异是因为“迪莫弗斯”根本不是一个台球。[qh]

It's a loosely bound rubble pile as DART's final closing images showed. [qh]

正如DART的结束阶段图像所示，“迪莫弗斯”是由松散的碎石堆组成。[qh]

So when DART slammed into it, it ejected a huge plume, a long tail of debris, containing more than 2 million pounds of stuff, which imparted recoil, basically, to Didymos. It's a bit like a kick from a shotgun.[qh]

因此，当DART撞击“迪莫弗斯”时，它喷出了巨大的羽流，一长串碎石，包含了200多万磅的物质，这基本上赋予了“迪迪莫斯”后坐力。这有点与霰弹枪的后坐力相像。[qh]

Oh, wow. Well that really helps me visualize it a little bit more. [qh]

哦, 哇。这确实可以帮助我更直观地理解。[qh]

So DART was this $330 million spaceship the size of a golf cart — and it was completely obliterated by this asteroid in a matter of mere microseconds. [qh]

DART是一艘价值3.3亿美元的宇宙飞船、体积有高尔夫球车大小，它在短短几微秒内就被这颗小行星完全摧毁了。[qh]

Scientists seemed pretty confident that this was a smashing success — but what else would we need in order to ensure that any more dangerous asteroids headed for earth don’t obliterate us? [qh]

科学家们似乎很确信这是一次轰动性成功的尝试，不过，我们还需要了解什么才能确保任何撞向地球的更危险的小行星不会摧毁我们呢?[qh]

Great question, Tulika. What we really need to have is better situational awareness. [qh]

问得好，图利卡。我们真正需要的是更好的处境意识。[qh]

How many of these objects are out there? What are they made of? Where are they?[qh]

外太空还有多少这样的物体? 它们的组织结构是什么? 它们的位置在哪里?[qh]

And uh, who’s working on that now?[qh]

现在哪些人在研究这个?[qh]

Lots of different people.[qh]

很多不同的人。[qh]

The key is to get a catalog of different sizes of objects, their different orbits, maybe even what they're made of and figure out which ones are the most threatening.[qh]

关键是要了解一系列不同大小、处在不同轨道、甚至不同组织结构的天体，然后找出哪些天体是最具威胁性的。[qh]

So in terms of certain near term projects we've got Hera, is the first dimension. [qh]

在一些近期项目中，我们发现了“赫拉”，这是第一个维度。[qh]

That's a project from the European Space Agency. [qh]

这是欧洲航天局的一个项目。[qh]

It's named after the Greek goddess who was married to Zeus, I believe, the queen of the gods.[qh]

这颗行星是以希腊女神的名字命名的，她是宙斯的妻子，是诸神之后。[qh]