第2610期: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. 在太空估计中，遵循小行星活动的天文学家很少有一个足够大的物体摧毁整个城市，可以在2032年撞击地球。 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. 但是航天局官员说，即使这样的小行星不断前往地球的道路，现在，世界已经准备好捍卫自己的威胁。 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年将在2032年12月22日袭击地球有3.1％的机会。这是现代如此大的太空岩石所预测的最高概率。 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·莫斯尔（Richard Moissl）是欧洲航天局（ESA）行星防御办公室的负责人。 他告诉法国新闻机构法新社，人们不应对这种预测感到恐慌。 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，直接小行星命中的几率预计会随着时间的流逝而不断上升。 但是，科学家说，在某个时刻，赔率可能会下降到零。 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." 莫斯尔说，他认为重要的是要记住，即使在不太可能的情况下，概率不断上升到100％，世界“没有防御”。 Here are some methods currently being considered as defensive measures to keep humanity safe in case there is a real threat. 以下是当前的一些方法，以防人类安全，以防有真正的威胁。Only one planetary defense method has been tried against an asteroid. 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. 仅尝试使用一种行星防御方法来针对小行星。 在2022年，NASA的双小行星重定向测试（DART）将航天器发送到160米宽的双层小行星中。 这项努力成功地改变了小行星围绕更大的空间岩石的轨道。 Bruce Betts is chief scientist for the nonprofit Planetary Society. He told AFP that space agencies could hit the 2024 YR4 asteroid with several spacecrafts, observing how each one changed the path. 布鲁斯·贝茨（Bruce Betts）是非营利行星社会的首席科学家。 他告诉法新社，太空机构可以用几个航天器击中2024年小行星，观察每个人如何改变路径。 The asteroid discovered in December is estimated to be 40-90 meters wide -- about half the size of Dimorphos.据估计，这颗小行星在 12 月发现时有 40-90 米宽，大约是 Dimorphos 大小的一半。"You have to take care not to overdo it," Moissl warned. 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. “你必须小心不要过度，”莫伊斯尔警告说。他说，这是因为如果航天器只部分摧毁了一颗小行星，它可能会将较小的太空岩石碎片送向地球。A separate idea would involve sending a large spacecraft to fly alongside a threatening asteroid. The spacecraft would not touch the asteroid, but would use its gravitational force to pull it away from Earth. 一个单独的想法将涉及将大型航天器与威胁性的小行星一起飞行。 航天器不会接触小行星，而是利用其引力将其从地球上拉开。 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.莫斯尔说，另一个非接触计划将使小行星附近的航天器在小行星附近弹出，以驱散原子的连续流，以将小行星脱离路线。 Scientists have also considered painting one side of the asteroid white. They believe this could increase the light the object reflects to make it slowly change course. 科学家还考虑绘画小行星白色的一侧。 他们认为这可能会增加物体反射的光，以使其缓慢改变路线。One idea is to use a nuclear weapon against a threatening asteroid. 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. 一个想法是使用核武器来防止威胁性的小行星。 在实验室测试中，研究人员发现，来自核爆炸的X射线可能会移动岩石。 但这被认为是宽公里的小行星的计划，例如杀死恐龙的小行星。 而且该方法还具有核爆炸可能会使小行星落入地球的其他部分的风险。 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. 一种类似的方法（但被认为危险的较小）将涉及从航天器射击激光束以摧毁小行星的一侧，以便将其远离地球。Moissl said that if all else fails, at least the world will have a good idea where a threatening asteroid would strike. 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. 莫斯尔说，如果其他所有问题都失败了，至少世界将在威胁性小行星袭击的地方有一个好主意。 由于天文学家认为大多数小行星最多都会威胁要摧毁一个城市，因此可以组织努力使人们在罢工之前离开该地区。 "Seven-and-a-half years is a long time to prepare," Moissl added. 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. Moissl补充说：“七年半的准备时间是很长的时间。” 他还指出，即使涉及2024年的赔率上升，小行星仍有大约97％的机会错过地球。