A new study suggests that an asteroid strike by an American spacecraft likely changed the shape of the targeted object.
一项新的研究表明，美国航天器的小行星撞击可能改变了目标物体的形状。
NASA crashed the DART spacecraft into the asteroid Dimorphos in 2022. The asteroid strike happened about 11 million kilometers from Earth.
美国宇航局 (NASA) 于 2022 年将 DART 航天器撞向小行星 Dimorphos。小行星撞击发生在距地球约 1100 万公里处。
The experiment tested a method for changing the orbit of some asteroids to prevent them from possibly crashing into our planet in the future.
该实验测试了一种改变一些小行星轨道的方法，以防止它们将来可能撞击我们的星球。
NASA has said its studies of the crash showed it was successful because the force of the strike changed the asteroid’s orbit around a larger asteroid Didymos. NASA’s measurements also found the strike reduced the orbital period of Dimorphos by 33 minutes.
美国宇航局表示，对这次撞击的研究表明这次撞击是成功的，因为撞击的力量改变了小行星围绕较大小行星迪迪莫斯的轨道。 NASA 的测量还发现，这次撞击使 Dimorphos 的轨道周期缩短了 33 分钟。
Such a major crash would normally create a large crater in the targeted object. But a new study presents evidence that the crash made more than a hole – it likely changed the shape of the whole asteroid.
此类重大碰撞通常会在目标物体上形成一个大坑。但一项新的研究提供的证据表明，这次撞击造成的不仅仅是一个洞——它很可能改变了整个小行星的形状。
Astronomers at the University of Bern, in Switzerland carried out the research. A study detailing the findings recently appeared in the publication Nature Astronomy .
瑞士伯尔尼大学的天文学家进行了这项研究。最近发表在《自然天文学》杂志上的一项详细研究结果的研究。
The team used a computer simulation system to study the changes to Dimorphos that resulted from the crash. The system aimed to recreate the breakup of space objects that have been hit.
该团队使用计算机模拟系统来研究因坠机而导致的 Dimorphos 的变化。该系统旨在重现被击中的空间物体的破碎情况。
The researchers said their simulation method has been used in the past to recreate space objects crashing into each other. For example, the team said it confirmed the results of a Japanese spacecraft collecting a sample from the Ryugu asteroid in 2019.
研究人员表示，他们的模拟方法过去曾被用来重现太空物体相互碰撞的情况。例如，该团队表示，它证实了日本航天器在 2019 年从龙宫小行星收集样本的结果。
Sabina Raducan is with the Physics Institute of the University of Bern. She helped lead the project. Raducan described the simulation process in a statement as “computationally intensive.” In total, she said 250 simulations were completed, which reproduced the first two hours after the asteroid strike.
Sabina Raducan 在伯尔尼大学物理研究所工作。她帮助领导了该项目。 Raducan 在一份声明中将模拟过程描述为“计算密集型”。她说总共完成了 250 次模拟，重现了小行星撞击后的前两个小时。
The researchers used all available information about NASA’s operation. These included the predicted shape of Dimorphos, data on the strike itself, as well as the size of the cloud the crash left behind. In addition, the team aimed to estimate unknown details about the asteroid and the surrounding area.
研究人员使用了有关 NASA 运作的所有可用信息。其中包括 Dimorphos 的预测形状、撞击本身的数据以及坠机留下的云的大小。此外，该团队的目标是估计有关小行星及其周边地区的未知细节。
“Then what we did is check which of the simulation run outcomes most closely match observed reality,” Raducan said.
“然后我们所做的是检查哪些模拟运行结果最接近观察到的现实，”拉杜坎说。
She added that results of the research provided clear evidence that the crash turned Dimorphos into a relatively weak “ rubble pile ” asteroid. Raducan explained this meant that the object is currently being held together “by the asteroid’s extremely weak gravity” rather than a solid and strong mass.
她补充说，研究结果提供了明确的证据，表明这次撞击使 Dimorphos 变成了一颗相对较弱的“碎石堆”小行星。拉杜坎解释说，这意味着该物体目前是“通过小行星极弱的引力”而不是坚固而坚固的质量结合在一起的。
The researchers noted that the results of the simulation and the team’s examinations partly explain why the crash was so effective in changing the path of the asteroid.
研究人员指出，模拟结果和团队的检查部分解释了为什么这次撞击如此有效地改变了小行星的路径。
Raducan said the results also persuaded the team that “the likelihood is that the crater grew to encompass the entire body itself, so that Dimorphos ended up being completely reshaped.” It is therefore unlikely that a crater still exists after the crash.
拉杜坎表示，研究结果也让研究小组相信，“陨石坑有可能扩大到覆盖整个身体，因此迪莫福斯最终被彻底重塑。”因此，坠机后陨石坑不太可能仍然存在。
The researchers said the existence of a crater can be investigated further by a European Space Agency (ESA) spacecraft. The spacecraft, called Hera, is preparing for a possible launch in October.
研究人员表示，欧洲航天局（ESA）的航天器可以进一步调查陨石坑的存在。这艘名为“赫拉”(Hera) 的航天器正在为 10 月份的发射做准备。
ESA says Hera’s cameras and instruments will carry out detailed studies of Dimorphos and the asteroid it orbits, Didymos. During the operation, the spacecraft will aim to collect the most data yet on such an asteroid system.
欧空局表示，赫拉的相机和仪器将对 Dimorphos 及其绕轨道运行的小行星 Didymos 进行详细研究。在操作过程中，航天器的目标是收集有关此类小行星系统的最多数据。