評論
打印
Okay, so there's an asteroid heading toward the Earth. Whatdo we do?
我們來假設，有顆小行星要撞地球啦，我們怎么辦呢？
Does our future really rest in the hands of Hollywood, Bruce Willis and a ragtag team ofminers like in the movie Armageddon?
難道真要想好萊塢電影《世界末日》里演的似的，把未來交到布魯斯·威利斯和他那幫烏合之眾手里？
Sure, we could wait until danger is imminent and then hope that a well placed nuclear explosionwould shatter or deflect the monster asteroid threatening humanity, but is this our only option?
我們當然也能聽任危機發展下去，在最后關頭期待一枚核彈把帶有毀滅威力的小行星擊碎或者打偏。不過這難道是人類的唯一選擇？
The answer is that it depends on how big the asteroid is, how far away it is, and How much timewe have before impact?
這個嘛，要看這顆小行星有多大，離地球有多遠，我們有多少危機應對時間啦。
Because there's lots of space debris out there, odds are that the threatening object won't be oneof the giant Earth-destroying asteroids that NASA is already tracking, but a smaller meteoroid capable of causing regional devastation.
足以毀滅地球的小行星早已上了NASA的定位追蹤名單。但宇宙里到處是太空垃圾，很可能沒等那些小行星威脅到地球，一些更小的流星就已足以造成地域性災難了。
With enough warning, though, we could crash a robotic spacecraft into the object and change its trajectory so that it'll sail by Earth.
不過，有了充足的預警，我們可以發射一些無人太空飛行器，把這些小天體撞離原定軌道。
We know we have the technology for this, because NASA has already successfully rammed a spacecraft into a comet to study the comet's composition.
這種技術早就有了，NASA就曾把一架飛行器撞向顆彗星，用以研究彗星的成分。
There are also rare instances when space objects pass close by several years before returning on a collision course with Earth.
也有一種很少見的情況：一些天體早先只是擦過近地軌道，數年后飛回來時，卻可能撞上地球。
Here even a tiny change in trajectory during the first pass would resultin big payoff later.
天體軌道極細微的變化都可能導致今后的大災難。
In these cases, we could use a spacecraft's mass and gravitational field to nudge the space object off course without shattering it and creating potentially dangerous fragments.
這種情況下，利用太空飛行器的質量和重力場，能將致命天體引偏些。用不著擊碎它，這樣也就不會產生可能威脅到地球安全的一堆碎片了。
Obviously, early warning is key, which is why NASA has issued a grand challenge to scientists invarious disciplines, institutions and agencies to work together to uncover ways of detecting,characterizing and interacting with asteroids.
顯然，早期預警是關鍵。這也是為什么NASA給學界和各大相關機構出了個大挑戰，讓大家聯合起來，預先測算分析和處理各種小行星的運行情況。
Because when it comes to the future of the Earth,Bruce Willis can only do so much.
因為一旦真的等到災難臨頭，布魯斯·威利斯可救不了人類。
