第2219期:NASA Spacecraft Unlocks Asteroid Dinkinesh’s History

NASA's Lucy spacecraft visited a little asteroid called Dinkinesh last November. The visit, scientists say, unlocks a surprisingly interesting history of the asteroid along with its companion, Selam.NASA的露西号航天器去年十一月拜访了一个名为Dinkinesh的小行星。科学家们表示，这次拜访揭示了该小行星及其伴侣Selam的一个令人惊讶的有趣历史。Asteroids are ancient objects from the beginning of the solar system. They offer clues about how Earth and other planets formed about 4.5 billion years ago.小行星是太阳系形成初期的古老天体。它们提供了关于地球和其他行星在大约45亿年前如何形成的线索。The U.S. space agency launched Lucy in 2021 on a 12-year mission to study asteroids. The mission is especially interested in Jupiter's Trojan asteroids, two groups of space rocks that lead and follow the giant planet as it orbits the sun.美国航天局在2021年发射了露西号，执行一个为期12年的小行星研究任务。该任务特别关注木星的特洛伊小行星，这两组空间岩石在木星绕太阳运行时分别位于其前后。On the way, Lucy flew past Dinkinesh and Selam in the inner edge of the main asteroid belt. The spacecraft observed ridges, trough structures and other features on Dinkinesh.在途中，露西号飞过了主小行星带内缘的Dinkinesh和Selam。航天器观察到了Dinkinesh上的山脊、槽状结构和其他特征。Dinkinesh has a diameter of nearly 720 meters. Selam is made up of two similarly sized lobes, one about 230 meters wide and the other about 210 meters. Selam orbits Dinkinesh once about every 53 hours at a distance of about 3.1 kilometers.Dinkinesh的直径接近720米。Selam由两个大小相似的叶状体组成，一个约230米宽，另一个约210米宽。Selam以大约每53小时绕Dinkinesh一圈，距离约3.1公里。It appears, the researchers said, that a big piece of rock broke free sometime in the past from Dinkinesh. The rock was about a quarter its total size, creating a trough on its surface and sending debris into space. Some of this debris, they said, fell back onto Dinkinesh's surface to form a ridge structure.研究人员表示，过去某个时候，一大块岩石从Dinkinesh上脱落下来。该岩石约占其总大小的四分之一，形成了一个槽，并将碎片送入太空。他们说，其中一些碎片重新落回Dinkinesh的表面，形成了一个山脊结构。Other materials came together to form Selam, becoming what is called a contact-binary moonlet.其他材料聚集在一起形成了Selam，成为了所谓的接触双星小卫星。Katherine Kretke, from the Southwest Research Institute in Colorado, is a co-writer of the study published in Nature. She said that “a contact-binary is when it appears that a single body is composed of two objects that collided gently enough not to become disrupted.”来自科罗拉多州西南研究所的Katherine Kretke是发表在《自然》杂志上的这项研究的共同作者。她说，“接触双星是指看起来由两个相互碰撞且碰撞力度足够轻不会破碎的天体组成的单一天体。”Kretke said they are common in the solar system, but Selam was “the first time a contact-binary has been observed orbiting another asteroid.”Kretke表示，它们在太阳系中很常见，但Selam是“第一次观测到的绕着另一颗小行星运行的接触双星。”Simone Marchi is another co-writer of the study. He said, "A planet like Earth formed by the accumulation of countless small bodies. Understanding the properties of small asteroids such as Dinkinesh and Selam helps us to have a better picture of the earliest phases of planet formation.”Simone Marchi是该研究的另一位共同作者。他说：“像地球这样的行星是由无数小天体聚集形成的。了解像Dinkinesh和Selam这样的小行星的性质，有助于我们更好地了解行星形成的最初阶段。”NASA's spacecraft was named for the Ethiopian fossil of the extinct human relative Australopithecus called “Lucy.” That fossil has provided information about early human beings, much like asteroids provide knowledge of planetary formation.NASA的航天器以埃塞俄比亚发现的已灭绝人类亲属——南方古猿的化石“露西”命名。那块化石提供了关于早期人类的信息，正如小行星提供了行星形成的知识。Dinkinesh is the Ethiopian name for the Lucy fossil, meaning "you are marvelous" in the Amharic language. Selam, the Ethiopian name for another Australopithecus fossil, means "peace" in Amharic.Dinkinesh是露西化石的埃塞俄比亚名称，在阿姆哈拉语中意为“你真了不起”。Selam是另一个南方古猿化石的埃塞俄比亚名称，在阿姆哈拉语中意为“和平”。Lucy will next visit the asteroid Donaldjohanson in 2025 in the main asteroid belt. The spacecraft is expected to visit 11 asteroids in total.露西号下一次将在2025年拜访主小行星带中的小行星Donaldjohanson。预计该航天器将总共拜访11颗小行星。