中国成为首个从月球背面取回岩石的国家
【中美创新时报2024 年 6 月 26 日编译讯】（记者温友平编译） 周二（25日），中国将一个装满月球土壤的太空舱从月球背面送回地球，这是其雄心勃勃的月球和太阳系其他部分探索计划的最新成功。《纽约时报》记者卡特里娜·米勒（Katrina Miller）对此作了下述报道。
中国国家航天局的嫦娥六号着陆器在历时 53 天的任务后取回了该样本，突显了中国在太空领域日益增强的能力，并取得了自 2007 年开始的一系列月球任务中的又一次胜利，迄今为止这些任务几乎毫无瑕疵地执行了。
“这是全世界科学家的一件大事，”中国地质大学行星地质学家龙晓在一封电子邮件中写道，并补充说这也是“全人类值得庆祝的事情”。
这种情绪和国际月球样本交换的前景凸显了人们对中国机器人登陆月球和火星任务将有助于促进对太阳系的科学理解的希望。与这些可能性形成鲜明对比的是，华盛顿和其他地方的观点认为，周二的成就是 21 世纪具有地缘政治色彩的太空竞赛的最新里程碑。
今年 2 月，一艘私人运营的美国航天器登陆月球。美国宇航局也在开展阿尔特弥斯计划，让美国人重返月球表面，尽管它的下一个任务，即宇航员绕月飞行，由于技术问题而被推迟。
中国也在寻求扩大其在月球上的存在，在未来几年内将更多的机器人降落在月球上，并最终让人类宇航员登陆月球。
为了实现这一目标，中国采取了缓慢而稳定的方法，实施了几十年前设计的机器人月球探测计划。该计划以中国月亮女神嫦娥命名，前两次任务绕月飞行，拍摄并绘制月球表面地图。随后是嫦娥三号，它于 2013 年降落在月球近侧，并部署了玉兔一号探测器。2019 年，嫦娥四号紧随其后，成为首个访问月球背面的航天器，并将玉兔二号探测器送上月球表面。
一年后，嫦娥五号着陆，将近 4 磅的近侧月球风化层送回地球。这一成就使中国成为继美国和苏联之后第三个实现从月球采集样本的复杂轨道编排的国家。
香港大学月球地质学家钱玉琪表示，嫦娥五号和嫦娥六号的机动都是中国未来载人登月任务的试运行，与 20 世纪 60 年代和 70 年代的阿波罗任务一样，需要着陆月球表面，然后发射人类。
在致力于将宇航员送上月球的同时，中国的长期战略是为了解太阳系付出科学代价。
嫦娥五号的样本比美国或苏联在 20 世纪 60 年代和 70 年代收集的月球物质更年轻。它主要由玄武岩或古代火山喷发的冷却熔岩组成。
两个中国领导的研究小组得出结论，玄武岩大约有 20 亿年的历史，这表明月球上的火山活动比美国阿波罗和苏联月球样本推断的时间范围至少长 10 亿年。
嫦娥六号于 5 月 3 日发射，其科学野心更大：从月球背面带回物质。月球正面主要是广阔的黑暗平原，那里曾是古代熔岩流淌的地方。但背面的平原较少。它还拥有更多的陨石坑和更厚的地壳。
而且由于那一半从未面向地球，因此无法直接与月球背面的着陆器进行通信，因此很难成功到达。中国航天局依靠之前发射到月球轨道的两颗卫星在嫦娥六号访问期间与其保持联系。
周二，样品容器重新进入地球大气层，然后降落在内蒙古四子王旗地区的表面，地面工作人员在那里努力将其回收。
当科学家获得月球背面的土壤时，他们将比较新回收的玄武岩与月球正面玄武岩的成分。这可能有助于他们推断月球的火山活动如何导致其两半演化不同。
任务小组还将寻找周围地区的物质，这些物质因彗星和小行星撞击而从其原始位置飞离。钱玉琪说，如果撞击足够强烈，这些碰撞可能会从月球下地壳和上地幔中挖掘出物质。这可能会让我们深入了解月球内部的结构和成分。
这些撞击产生的熔岩也可能为南极-艾特肯盆地的年龄及其形成的时代提供线索，科学家认为在此期间，大量小行星和彗星轰击了太阳系内部。
钱玉琪说，这一时期“彻底改变了月球的地质历史”，也是“地球演化的关键时期”。
本文最初发表于《纽约时报》。
题图：周二（25日），官员们准备回收嫦娥六号月球探测器的着陆舱，嫦娥六号探测器降落在中国北方的内蒙古。STRINGER/AFP VIA GETTY IMAGES
附原英文报道：
China becomes first country to retrieve rocks from the moon’s far side
By Katrina Miller New York Times,Updated June 25, 2024
China brought a capsule full of lunar soil from the far side of the moon down to Earth on Tuesday, achieving the latest success in an ambitious schedule to explore the moon and other parts of the solar system.
The sample, retrieved by the China National Space Administration’s Chang’e-6 lander after a 53-day mission, highlights China’s growing capabilities in space and notches another win in a series of lunar missions that started in 2007 and have so far been executed almost without flaw.
“This is a major event for scientists worldwide,” Long Xiao, a planetary geologist at China University of Geosciences, wrote in an email, adding it’s also “a cause for celebration for all humanity.”
Such sentiments and the prospects of international lunar-sample exchanges highlighted the hope that China’s robotic missions to the moon and Mars will serve to advance scientific understanding of the solar system. Those possibilities are contrasted by views in Washington and elsewhere that Tuesday’s achievement is the latest milestone in a 21st century space race with geopolitical overtones.
In February, a privately operated American spacecraft landed on the moon. NASA is also pursuing the Artemis campaign to return Americans to the lunar surface, although its next mission, a flight by astronauts around the moon, has been delayed because of technical issues.
China, too, is looking to expand its presence on the moon, landing more robots there, and eventually human astronauts, in the years to come.
Building toward that goal, it has taken a slow and steady approach, executing a robotic lunar exploration program it devised decades in advance. Named after the Chinese moon goddess Chang’e, the program’s first two missions orbited the moon to photograph and map its surface. Then came Chang’e-3, which landed on the lunar near side in 2013 and deployed a rover, Yutu-1. It was followed in 2019 by Chang’e-4, which became the first vehicle to visit the moon’s far side and put the Yutu-2 rover on the surface.
One year later, it landed Chang’e-5, which sent nearly 4 pounds of near-side lunar regolith to Earth. The achievement made China only the third country — after the United States and the Soviet Union — to achieve the complex orbital choreography of collecting a sample from the moon.
According to Yuqi Qian, a lunar geologist at the University of Hong Kong, the maneuvers of Chang’e-5 and Chang’e-6 are both test runs for China’s future crewed missions to the moon, which, like the Apollo missions of the 1960s and ‘70s, need to land and then launch humans from the lunar surface.
While it works toward putting astronauts on the moon, China’s long-term strategy is paying scientific benefits for understanding the solar system.
The Chang’e-5 sample was younger than the lunar material collected by the Americans or Soviets in the 1960s and ’70s. It is made up mainly of basalts, or cooled lava from ancient volcanic eruptions.
Two Chinese-led research teams concluded that the basalts were about 2 billion years old, suggesting that volcanic activity on the moon extended at least a billion years beyond the time frame deduced from the US Apollo and Soviet Luna samples.
Chang’e-6 launched May 3 with even grander scientific ambitions: bringing back material from the far side of the moon. The near side of the moon is dominated by wide, dark plains where ancient lava once flowed. But the far side has fewer of those plains. It also has more craters and a thicker crust.
And because that half never faces Earth, it is impossible to directly communicate with landers on the lunar far side, making it difficult to reach successfully. The Chinese space agency relied on two satellites it previously launched into orbit around the moon to remain in touch with Chang’e-6 during its visit.
On Tuesday, the sample container reentered Earth’s atmosphere and then parachuted to the surface of the Siziwang Banner area of Inner Mongolia, where ground crews worked to recover it.
When scientists take possession of the far-side soils, they will compare the composition of the newly recovered basalts with those from the lunar near side. That may help them deduce how the moon’s volcanic activity caused its two halves to evolve differently.
The mission team will also be looking for material from surrounding regions, blasted away from their original sites by impacts with comets and asteroids. If strong enough, these collisions may have excavated material from the lower crust of the moon and its upper mantle, Qian said. That could lead to insights about the structure and composition of the lunar interior.
Melted rock from those impacts could also yield clues about the age of the South Pole-Aitken basin and the era in which it formed, during which scientists believe a barrage of asteroids and comets bombarded the inner solar system.
This period “totally changed the geological history of the moon,” Qian said, and was also “a critical time for the evolution of the Earth.”
