编辑：这些话题听起来很科幻，但其实离我们并不遥远。今年初，"一颗编号为2024 YR4的小行星可能 会在2032年撞击地球"的消息曾引起热议。就在9月3日晚，一颗近地小行星2025 QD8在21万公里外与地 球"擦肩而过"。本期院士讲科普，我们邀请中国探月工程总设计师、深空探测实验室主任兼首席科学家 吴伟仁院士，和大家聊聊探索小行星的那些事。 浩瀚的太阳系中，围绕太阳公转的不仅有八大行星，还有千千万万个头不等、形状各异、运行轨道不同 的小行星。小行星是太阳系原始星云在长成大行星过程中的中间产物，也被称为太阳系建筑大厦的砖 石。在前不久举行的第三届深空探测（天都）国际会议上，我国科学家提出了中国小行星探测、防御和 资源开发利用构想，并向国际伙伴发出了合作倡议。 太阳系内小行星分布示意图。深空探测实验室供图 数十亿颗小行星，是太阳系形成与演化的"活化石" 地球防御小行星撞击漫画。杨仕成绘 网友：最近看到一个热搜话题，"我国规划撞击一颗小行星"，有种科幻照进现实的感觉。小行星是颗什 么"星"，为什么要去撞击它？假如小行星撞地球，我们怎么办？ 在小行星防御方面，2005年，美国成功实施了"深度撞击"任务，验证了动能撞 ...

Core Viewpoint - The article discusses the significance of asteroid exploration, defense, and resource utilization, emphasizing the need for a comprehensive strategy to address potential threats from near-Earth asteroids and the opportunities they present for future space economy [5][11]. Group 1: Asteroid Characteristics and Distribution - The solar system contains billions of asteroids, categorized into near-Earth asteroids, main belt asteroids, Trojan asteroids, centaur asteroids, and Kuiper belt asteroids, serving as "living fossils" of solar system formation [6]. - Near-Earth asteroids are defined as those with a perihelion distance of less than 1.3 AU, and they are rich in metals, water ice, and other resources, classified into metallic, carbonaceous, and silicate types [6][11]. Group 2: Current Exploration and Defense Efforts - Japan's Hayabusa mission was the first to return samples from an asteroid, while China's Chang'e 2 conducted a flyby of the asteroid Toutatis, showcasing advancements in asteroid exploration [7]. - The U.S. has successfully tested kinetic impactor technology for asteroid deflection, with the DART mission demonstrating the ability to alter an asteroid's trajectory [7][9]. - China is planning to implement a demonstration mission for asteroid deflection by 2027, aiming to validate the feasibility of kinetic impact techniques [9][10]. Group 3: Threats Posed by Asteroids - Near-Earth asteroids pose significant threats, with historical events like the Chicxulub impact leading to mass extinctions and recent incidents causing damage and injuries [8][9]. - As of March 2025, only 1% of near-Earth asteroids have been cataloged, highlighting the challenges in monitoring and tracking these celestial bodies [8]. Group 4: Resource Development Potential - Asteroids hold immense economic value, with estimates suggesting that over 700 of the 1,000 well-studied asteroids could each be worth over $100 trillion, and the total value of main belt asteroid resources could exceed $70 trillion in the next 30 years [12]. - The development of asteroid resources involves a series of activities including exploration, extraction, processing, and transportation, potentially leading to a "space supply chain" [11][12].

Core Viewpoint - The article discusses the significance of asteroid exploration, defense, and resource utilization, highlighting the potential threats posed by near-Earth asteroids and the need for international collaboration in addressing these challenges [4][7][10]. Group 1: Asteroid Characteristics and Distribution - The solar system contains billions of asteroids, categorized into near-Earth asteroids, main belt asteroids, Trojan asteroids, centaur asteroids, and Kuiper belt asteroids, serving as "living fossils" of solar system formation and evolution [5]. - Near-Earth asteroids are defined as those with a perihelion distance of less than 1.3 AU, and they are rich in resources such as iron, nickel, platinum group metals, and water ice [5][6]. Group 2: Exploration and Defense Initiatives - Japan's Hayabusa mission successfully returned samples from the Itokawa asteroid, while China's Chang'e 2 conducted a flyby of the Toutatis asteroid, showcasing advancements in asteroid exploration [6]. - The U.S. has successfully implemented kinetic impactor missions, such as the DART mission, to test the feasibility of altering asteroid trajectories [6][7]. - China plans to launch the Tianwen-2 mission to sample a near-Earth asteroid by May 2025, furthering its capabilities in asteroid exploration and defense [6][9]. Group 3: Threats Posed by Asteroids - Near-Earth asteroids are considered one of the most significant potential threats to Earth, with historical events like the Chicxulub impact leading to mass extinctions [7]. - As of March 2025, 38,171 near-Earth objects have been discovered, but only a small fraction has been cataloged, indicating a need for improved monitoring and tracking systems [7][8]. Group 4: Resource Development Potential - Asteroids hold significant economic value, with estimates suggesting that over 700 of the 1,000 well-studied asteroids could each be worth over $100 trillion, and the total value of main belt asteroid resources could exceed $70 trillion in the next 30 years [11]. - The development of asteroid resources involves a series of activities including exploration, extraction, processing, and transportation, potentially leading to a "space supply chain" [10][11]. Group 5: International Collaboration and Future Plans - China has proposed a comprehensive strategy for asteroid detection and defense, emphasizing the need for a collaborative international approach to build a robust asteroid monitoring and defense system [8][9]. - The planned demonstration of kinetic impactor missions aims to validate the technology's effectiveness in altering asteroid trajectories and ensuring Earth's safety [9].