AI 中文总结
本研究结合现代观测与轨道-热化学演化模型，证实伽利略卫星存在约0.8-2.0 Gyr前建立的极限环，明确其当前演化状态及未来任务的评估方向。
AI 中文摘要
木卫一、木卫二和木卫三在拉普拉斯平均运动共振中运行，它们的轨道与热化学演化存在强耦合[1-5]。受迫偏心率维持着潮汐耗散，为木卫一的火山活动提供动力，并维持木卫二的地下海洋[6-8]。潮汐加热取决于卫星的偏心率、半长轴和内部属性；轨道演化则取决于卫星耗散对共振动力学的影响[4,8]。这种耦合演化尚未在受现代观测约束的自洽框架中得到处理。本研究结合现代自行观测、地球物理测量（包括迁移率、地表热流、潮汐响应和转动惯量[9-13]）与轨道-热化学演化模型，约束卫星的长期演化与当前状态。研究表明，联合观测指向一个持续的晚期极限环，该极限环可能在约0.8-2.0 Gyr前通过热演化与轨道演化的反馈建立；当前状态在该振荡分支内重复，其周期约为95-150 Myr。当前木卫一处于高耗散状态并向内迁移，木卫二和木卫三持续向外迁移；预测木卫二在该周期内会经历向内迁移阶段。周期内，木卫一的平均熔融分数变化显著（约10-30%），木卫二的冰壳厚度变化约3-15 km。木卫二和木卫一的预测结构将由未来任务（包括Europa Clipper、JUICE和IVO[14-17]）进行评估。
英文摘要
Io, Europa, and Ganymede orbit in the Laplace mean-motion resonance, where their orbital and thermochemical evolution are strongly coupled [1-5]. Forced eccentricities sustain tidal dissipation, powering Io's volcanism and maintaining Europa's subsurface ocean [6-8]. Tidal heating depends on the moons' eccentricities, semimajor axes, and interior properties. Orbital evolution depends on how satellite dissipation affects the resonant dynamics [4, 8]. This coupled evolution has not been treated in a self-consistent framework constrained by modern observations. Here, we combine modern astrometric and geophysical measurements of migration rates, surface heat fluxes, tidal response, and moment of inertia [9-13] with an orbital-thermochemical evolution model to constrain the long-term evolution and present state of the moons. We show that the joint observations select an ongoing late-time limit cycle, likely established $\sim$0.8-2.0 Gyr ago through feedback between thermal and orbital evolution. The present-day state recurs within this oscillatory branch, whose cycles repeat every $\sim$95-150 Myr. Io presently experiences high dissipation and migrates inward, whereas Europa and Ganymede continue to migrate outward. Europa is predicted to undergo episodes of inward migration during the cycle. During the cycles, Io's mean melt fraction varies substantially ($\sim$10-30%), while Europa's ice-shell thickness varies by $\sim$3-15 km. The predicted structures of Europa and Io will be assessed by future missions including Europa Clipper, JUICE, and IVO [14-17].
