CAREER: GLOW: The Long-Term Histories of Geologically Active Solar System Moons from Isotope Geochemistry

加州理工学院（California Institute of Technology）的凯瑟琳·德·克勒（Katherine de Kleer）博士进行了实验，测量太阳系外天体内部释放的气体。今天，当我们在太阳系内观察地球和我们的行星邻居时，我们只看到了它们一生的快照。为了把这个快照放在上下文中，研究者想要了解他们的长期历史，或者他们是如何成为今天的样子的。在像地球这样具有活跃地质（板块构造、火山活动等）的星球上，我们用来研究它们过去的特征已经被抹去了。对质量稍有不同的化学元素的测量为研究行星更遥远的历史提供了难得的机会。有了新的望远镜，这些测量现在才成为可能，用于太阳系的外部部分。这位研究员和她的研究小组将使用新的望远镜观测研究太阳系卫星和矮行星的演化。通过将这些观测结果与模型相结合，这项工作将促进对这些世界的热流和质量损失历史的理解。该计划将涉及本科生到博士水平的学生，以及博士后学者。它还将培训年轻科学家为公众制作适合各种环境的创新的、互动的科学内容。本项目将同位素地球化学已建立的技术应用于用天文学方法观测到的地质活跃卫星，从而将天文学、地质学和地球化学的学科联系起来。它将具体地提供洞察：在伽利略卫星潮汐加热的寿命；土卫二的质量损失和表面-内部交换过程；以及被捕获卫星的形成和迁移历史。该项目将利用来自阿塔卡马大型（亚）毫米波阵列的新观测数据，将使用考虑所有同位素储层和相关物种交换率的模型进行解释，从而实现对地层和演化情景的稳健限制。这些结果将解决关于这些天体的基本问题，并将建立太阳系卫星的非生物同位素背景，这是使用同位素作为生物特征的重要的第一步。天文学司和地球科学司通过合作伙伴关系提供了共同资金，重点是来自其他世界的地球科学课程（GLOW）。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The investigator, Dr. Katherine de Kleer of the California Institute of Technology, has developed experiments to measure gases released from the interiors of bodies in the outer Solar System. When the Earth and our planet neighbors are viewed within the Solar System today, we see only a snapshot of their full lifetimes. In order to put this snapshot in context, the investigator would like to understand their long-term histories, or how they got to be the way they are today. On worlds, like Earth, that have active geology (plate tectonics, volcanism etc), the signatures that we might use to study their past have been erased. Measurements of chemical elements with slightly different masses provide a rare opportunity to study the more distant histories of planets. With new telescopes, these measurements are only now becoming possible for the outer part of the Solar System. The investigator and her research group will use new telescope observations study the evolution of Solar System moons and dwarf planets. By combining these observations with models, this work will advance understanding of the heat flow and mass loss histories of these worlds. The program will involve students from undergraduate to PhD level, as well as postdoctoral scholars. It will additionally train young scientists in producing innovative, interactive science content for the public, tailored to a range of settings.This project applies established techniques in isotope geochemistry to geologically-active moons observed with astronomical methods, thus bridging the disciplines of astronomy, geology, and geochemistry. It will specifically provide insight into: the longevity of tidal heating at the galilean satellites; the mass loss and surface-interior exchange processes at Enceladus; and the formation and migration histories of captured moons. The project will utilize new observations from the Atacama Large (sub-)Millimeter Array, which will be interpreted using models that will consider all isotope reservoirs and exchange rates for the relevant species, enabling robust bounds on formation and evolutionary scenarios. The results will address fundamental open questions about these objects, and will establish the abiotic isotope background for Solar System moons, an important first step towards using isotopes as biosignatures.Co-funding was provided by the Division of Astronomy and Division of Earth Sciences through a partnership focused on Geoscience Lessons for and from Other Worlds (GLOW).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.