Collisional fragments of Jupiter Trojans as windows into the formation of the solar system

这项由加州理工学院开展的项目旨在解决木星木马的起源问题，木马是木星轨道上的小行星星团。这两个星系团位于轨道上引力稳定的点，一个在行星的前面，另一个在行星后面。这些小行星的起源仍不得而知。这个项目是为了研究木星特洛伊木马的组成，这些木马最近经历了碰撞，以了解它们的历史。将利用凯克天文台和阿塔卡马大毫米/亚毫米阵列(ALMA)等几个地面观测站的数据来检查暴露的物质。该项目的更广泛影响包括对Coursera上的一个名为太阳系科学的免费在线课程进行重大升级。升级将包括最近5年的太空探索，并在太阳系早期动力学历史研究的基础上开发新的丰富内容。木星木马的组成为了解太阳系的动力学历史提供了关键的观测线索，但人们对这些物体的组成知之甚少，因为长期的辐射和持续的粒子轰击使它们的表面变成了黑色的耐火沉积物，没有可识别的光谱特征。这个多方面的项目将研究最近木星特洛伊小行星的碰撞碎片。用新暴露的内部物质观察最近的碎片将提供对它们的组成、形成历史和早期太阳系动力学演化的本质的洞察。将对大小约为5公里的物体进行系统研究，其中所有物体应持续处于碰撞活跃状态，最大可达约40公里，只有偶尔发生碰撞的物体应经历最近的碰撞。使用Palomar可见光光度法、Keck红外光谱和ALMA辐射测量法的组合，将检查这些碎片的反照率、成分和碰撞历史。这项研究将揭示这些天体的起源，它们与小行星主带或柯伊伯带的联系，进而揭示早期太阳系的动力学历史。这一奖项反映了美国国家科学基金会的法定任务，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project carried out at the California Institute of Technology seeks to address the origin of Jupiter Trojans, which are clusters of asteroids in Jupiter’s orbit. These two clusters sit at gravitationally stable points in the orbit, one ahead of the planet, and the other behind. The origin of these asteroids is still unknown. This project is to examine the composition of the Jupiter Trojans that have recently undergone collisions to obtain insight into their history. The exposed material will be examined using data from several ground-based observatories including the Keck Observatory and the Atacama Large Millimeter/submillimeter Array (ALMA). The broader impacts of this project include significant upgrades to a free online class available on Coursera called The Science of the Solar System. The upgrades are to include the last 5 years of space exploration and to develop new rich content based on the research into the early dynamical history of the solar system. The composition of the Jupiter Trojans provides a critical observational clue into the dynamical history of the solar system, but little is known about the compositions of these objects, because long term irradiation and continuous particle bombardment have turned their surfaces into dark refractory deposits with no identifiable spectral features. This multi-faceted project will study recent collisional fragments of Jupiter Trojan asteroids. Observing recent fragments with freshly exposed interior materials will provide insight into their composition, into their formation history, and the nature of the dynamical evolution of the early solar system. A systematic study will be carried out of objects in size from approximately 5 km, where all objects should be continuously collisionally active, up to approximately 40 km, where only the occasional object should have experienced a recent collision. Using combinations of Palomar visible photometry, Keck infrared spectroscopy, and ALMA radiometry, the albedo, composition, and collisional history of these fragments will be examined. This study will reveal the origin of these objects, their connection to the main belt of asteroids or to the Kuiper belt, and, by extension, the dynamical history of the early solar system.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.