保护地球免受小行星撞击的方法
📖 逐句对照翻译
Astronomers following asteroid activity in space estimate there is a very small chance an object large enough to destroy a whole city could strike Earth in 2032.
追踪太空中小行星活动的天文学家估计，2032年一个足以摧毁整座城市的天体撞击地球的可能性非常小。
But space agency officials say even if such an asteroid keeps heading on a path toward Earth, the world is now much better-equipped to defend itself against such a threat.
但航天局官员表示，即使这样的小行星继续朝地球方向飞行，如今世界也更有能力防御此类威胁。
The American space agency NASA recently estimated there was a 3.1 percent chance that asteroid 2024 YR4 would hit Earth on December 22, 2032.
美国航天局NASA最近估计，小行星2024 YR4在2032年12月22日撞击地球的概率为3.1%。
That is the highest probability predicted for such a large space rock in modern times.
这是现代预测到的对于如此巨大的太空岩石而言的最高概率。
Richard Moissl is head of the European Space Agency's (ESA) planetary defense office.
理查德·莫伊索尔是欧洲空间局（ESA）行星防御办公室主任。
While recognizing the risk the asteroid could present, he told the French news agency AFP people should not panic over such predictions.
尽管认识到这颗小行星可能带来的风险，但他告诉法新社，人们不应对此类预测感到恐慌。
Astronomers have noted that the more data they gather, the odds of a direct asteroid hit are expected to keep rising over time.
天文学家指出，他们收集的数据越多，小行星直接撞击地球的可能性预计会随时间推移而不断增加。
However, scientists say at a certain point the odds will likely drop down to zero.
然而，科学家表示，在某个时刻，这种可能性很可能会降至零。
Moissl said he thinks it is important to remember that even in the unlikely event the probability keeps rising to 100 percent, the world is "not defenseless."
莫伊塞尔表示，他认为重要的是要记住，即使概率不断上升至100%这种不太可能发生的情况，世界也“并非毫无防御能力”。
Here are some methods currently being considered as defensive measures to keep humanity safe in case there is a real threat.
以下是一些目前正在考虑的防御措施，用以在存在真实威胁时保障人类安全。
Send a spacecraft to hit it
发射一艘航天器去撞击它
Only one planetary defense method has been tried against an asteroid.
针对小行星的行星防御方法中，只有一种已被尝试过。
In 2022, NASA's Double Asteroid Redirection Test (DART) sent a spacecraft into the 160-meter-wide Dimorphos asteroid.
2022年，美国宇航局的双小行星重定向测试（DART）任务将一艘航天器撞向了宽160米的迪莫弗斯小行星。
The effort successfully changed the asteroid’s orbit around a larger space rock.
这次努力成功改变了这颗小行星围绕一颗更大太空岩石运行的轨道。
Bruce Betts is chief scientist for the nonprofit Planetary Society.
布鲁斯·贝茨是非营利组织行星协会的首席科学家。
He told AFP that space agencies could hit the 2024 YR4 asteroid with several spacecrafts, observing how each one changed the path.
他告诉法新社，航天机构可以用多艘航天器撞击2024 YR4小行星，观察每次撞击如何改变其轨道。
The asteroid discovered in December is estimated to be 40-90 meters wide -- about half the size of Dimorphos.
去年12月发现的这颗小行星估计宽40至90米，约为迪莫弗斯的一半大小。
"You have to take care not to overdo it," Moissl warned.
“你得注意不要做得太过火，”莫伊索尔警告说。
He said this is because if a spacecraft only partly destroys an asteroid, it could send smaller pieces of the space rock heading toward Earth.
他说，这是因为如果航天器只部分摧毁了一颗小行星，可能会使较小的太空岩石碎片飞向地球。
Non-contact methods
非接触式方法
A separate idea would involve sending a large spacecraft to fly alongside a threatening asteroid.
另一种设想是发射一艘大型飞船，与具有威胁的小行星并行飞行。
The spacecraft would not touch the asteroid, but would use its gravitational force to pull it away from Earth.
航天器不会接触小行星，而是会利用其引力将其拉离地球。
Moissl said another non-contact plan would put a spacecraft near the asteroid to eject a continuous flow of atoms to push the asteroid off course.
莫伊塞尔表示，另一种非接触式方案是将一艘航天器放置在小行星附近，喷射出连续的原子流，从而将小行星推离轨道。
Scientists have also considered painting one side of the asteroid white.
科学家们还考虑过将小行星的一面涂成白色。
They believe this could increase the light the object reflects to make it slowly change course.
他们认为这可以增加物体反射的光线，使其缓慢改变航向。
Contact methods
联系方式
One idea is to use a nuclear weapon against a threatening asteroid.
一个想法是使用核武器来对付具有威胁的小行星。
In laboratory tests, researchers found that X-rays from a nuclear blast could move a rock.
在实验室测试中，研究人员发现核爆炸产生的X射线能够移动岩石。
But this is considered more of a plan for kilometers-wide asteroids like the one that killed off the dinosaurs.
但这更多被视为针对数公里宽的小行星的计划，比如导致恐龙灭绝的那一颗。
And this method also carries the risk that a nuclear explosion could send additional pieces of the asteroid falling toward Earth.
而且这种方法还存在风险，核爆炸可能会将更多的小行星碎片推向地球。
A similar method – but one considered less dangerous – would involve shooting laser beams from a spacecraft to destroy the side of an asteroid in an effort to push it away from Earth.
一种类似但被认为危险性较小的方法是从航天器上发射激光束，摧毁小行星的一侧，力图将其推离地球。
If all else fails
如果一切都不奏效
Moissl said that if all else fails, at least the world will have a good idea where a threatening asteroid would strike.
莫伊塞尔表示，如果所有努力都失败，至少全世界能清楚地知道威胁性的小行星会撞击在哪里。
Since astronomers believe most asteroids would at most threaten to destroy one city, efforts could be organized to get people out of an area before a strike.
由于天文学家认为大多数小行星最多只会摧毁一座城市，因此可以组织力量在撞击发生前将人们撤离该地区。
"Seven-and-a-half years is a long time to prepare," Moissl added.
莫伊索补充说：“七年半的时间来准备是很长的。”
He also noted that even with the rising odds involving 2024 YR4, there is still about a 97 percent chance the asteroid will miss Earth.
他还指出，即便2024 YR4小行星撞击地球的概率上升，它仍有约97%的可能性会与地球擦肩而过。
I’m Jill Robbins.
我是吉尔·罗宾斯。
Daniel Lawler with Issam Ahmed reported this story for Agence France-Presse.
丹尼尔·劳勒与伊萨姆·艾哈迈德为法新社报道了此事。
Jill Robbins adapted it for Learning English.
吉尔·罗宾斯为《学习英语》改编了它。
