Methods for Protecting Earth against an Asteroid Strike

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.

跟踪太空中小行星活动的天文学家估计，一个足以摧毁整个城市的物体在 2032 年撞击地球的可能性很小。

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着地球前进，世界现在也更有能力抵御这种威胁。

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. That is the highest probability predicted for such a large space rock in modern times.

美国航天局 NASA 最近估计，小行星 2024 YR4 将于 2032 年 12 月 22 日撞击地球的可能性为 3.1%。 这是现代对如此大的太空岩石预测的最高概率。

Richard Moissl is head of the European Space Agency's (ESA) planetary defense office. While recognizing the risk the asteroid could present, he told the French news agency AFP people should not panic over such predictions.

理查德·莫伊斯尔 (Richard Moissl) 是欧洲航天局 (ESA) 行星防御办公室的负责人。 虽然认识到小行星可能带来的风险，但他告诉法国新闻社法新社，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. However, scientists say at a certain point the odds will likely drop down to zero.

天文学家指出，他们收集的数据越多，小行星直接撞击的可能性预计会随着时间的推移而不断上升。 然而，科学家表示，到了某个时候，这种可能性可能会降至零。

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."

莫伊斯尔表示，他认为重要的是要记住，即使在不太可能发生的情况下，概率不断上升至 100%，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.

以下是目前被认为是防御措施的一些方法，以在存在真正威胁时确保人类安全。

Send a spacecraft to hit it Only one planetary defense method has been tried against an asteroid.

派飞船去撞它 迄今为止，只有一种针对小行星的行星防御方法被尝试过。

In 2022, NASA's Double Asteroid Redirection Test (DART) sent a spacecraft into the 160-meter-wide Dimorphos asteroid. The effort successfully changed the asteroid’s orbit around a larger space rock. Bruce Betts is chief scientist for the nonprofit Planetary Society.

2022年，美国宇航局的双小行星重定向测试（DART）将一艘航天器送入了160米宽的Dimorphos小行星。 这项努力成功地改变了小行星围绕更大的太空岩石的轨道。 布鲁斯·贝茨是非营利性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. The asteroid discovered in December is estimated to be 40-90 meters wide -- about half the size of Dimorphos.

他告诉法新社，航天机构可能会用几艘航天器撞击 2024 YR4 小行星，观察每艘航天器如何改变路径。 12 月发现的这颗小行星估计宽 40 至 90 米，大约是 Dimorphos 大小的一半。

"You have to take care not to overdo it," Moissl warned.

“你必须注意不要做得太过分，”莫伊斯尔警告说。

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. A separate idea would involve sending a large spacecraft to fly alongside a threatening asteroid.

他说，这是因为如果航天器仅部分摧毁小行星，它可能会将较小的太空岩石碎片送向地球。 另一个想法是发送一艘大型航天器与一颗具有威胁性的小行星一起飞行。

The spacecraft would not touch the asteroid, but would use its gravitational force to pull it away from Earth. 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.

航天器不会接触小行星，但会利用其引力将其拉离地球。 莫伊斯尔表示，另一个非接触计划将在小行星附近放置一艘航天器，喷射连续的原子流，将小行星推离轨道。

Scientists have also considered painting one side of the asteroid white.

科学家们还考虑将小行星的一侧涂成白色。

They believe this could increase the light the object reflects to make it slowly change course. One idea is to use a nuclear weapon against a threatening asteroid.

他们相信这可以增加物体反射的光线，使其慢慢改变航向。 一个想法是使用核武器对抗威胁小行星。

In laboratory tests, researchers found that X-rays from a nuclear blast could move a rock. But this is considered more of a plan for kilometers-wide asteroids like the one that killed off the dinosaurs. And this method also carries the risk that a nuclear explosion could send additional pieces of the asteroid falling toward Earth. 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.

在实验室测试中，研究人员发现核爆炸发出的 X 射线可以移动岩石。 但这更多地被认为是针对数公里宽的小行星的计划，就像杀死恐龙的那颗小行星一样。 这种方法还存在核爆炸可能导致更多小行星碎片落向地球的风险。 一种类似的方法（但被认为危险性较小）将涉及从航天器发射激光束来摧毁小行星的侧面，以将其推离地球。

Moissl said that if all else fails, at least the world will have a good idea where a threatening asteroid would strike.

莫伊斯尔说，如果其他一切都失败了，至少世界将清楚地知道威胁性小行星将袭击哪里。

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. "Seven-and-a-half years is a long time to prepare," Moissl added.

由于天文学家认为大多数小行星最多只会威胁摧毁一座城市，因此可以组织努力，在袭击前将人们撤离某个地区。 “七年半的准备时间是很长的，”莫伊斯尔补充道。

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. Daniel Lawler with Issam Ahmed reported this story for Agence France-Presse.

他还指出，即使涉及 2024 YR4 的可能性不断上升，这颗小行星仍有大约 97% 的机会错过地球。 丹尼尔·劳勒和伊萨姆·艾哈迈德为法新社报道了这个故事。

Jill Robbins adapted it for Learning English. ______________________________________________ asteroid - n. any of the small rocky celestial bodies found especially between the orbits of Mars and Jupiter reflect – v. of light or sound. to move in one direction, hit a surface, and then quickly move in a different and usually opposite direction What do you think of this story? Write to us in the Comments Section.

吉尔罗宾斯将其改编为学习英语。 _____________________________________________ 小行星 - n.特别是在火星和木星轨道之间发现的任何小型岩石天体 反射——v.光或声音。朝一个方向移动，撞击一个表面，然后快速朝另一个方向（通常是相反的方向）移动 你觉得这个故事怎么样？ 在评论部分给我们写信。