Tobie G, Auclair-Desrotour P, Běhounková M, Kervazo M, Souček O, Kalousová K
Laboratoire de Planétologie et Géosciences, UMR 6112, CNRS, Nantes Université, Université d'Angers, Le Mans Université, Nantes, France.
IMCCE, CNRS, Observatoire de Paris, PSL University, Sorbonne Université, Paris, France.
Space Sci Rev. 2025;221(1):6. doi: 10.1007/s11214-025-01136-y. Epub 2025 Jan 16.
Tidal interactions play a key role in the dynamics and evolution of icy worlds. The intense tectonic activity of Europa and the eruption activity on Enceladus are clear examples of the manifestation of tidal deformation and associated dissipation. While tidal heating has long been recognized as a major driver in the activity of these icy worlds, the mechanism controlling how tidal forces deform the different internal layers and produce heat by tidal friction still remains poorly constrained. As tidal forcing varies with orbital characteristics (distance to the central planet, eccentricity, obliquity), the contribution of tidal heating to the internal heat budget can strongly change over geological timescales. In some circumstances, the tidally-produced heat can result in internal melting and surface activity taking various forms. Even in the absence of significant heat production, tidal deformation can be used to probe the interior structure, the tidal response of icy moons being strongly sensitive to their hydrosphere structure. In the present paper, we review the methods to compute tidal deformation and dissipation in the different layers composing icy worlds. After summarizing the main principle of tidal deformation and the different rheological models used to model visco-elastic tidal response, we describe the dissipation processes expected in rock-dominated cores, subsurface oceans and icy shells and highlight the potential effects of tidal heating in terms of thermal evolution and activity. We finally anticipate how data collected by future missions to Jupiter's and Saturn's moons could be used to constrain their tidal response and the consequences for past and present activities.
潮汐相互作用在冰质天体的动力学和演化过程中起着关键作用。木卫二剧烈的构造活动以及土卫二上的喷发活动，都是潮汐变形及其相关耗散表现的明显例子。虽然长期以来人们一直认为潮汐加热是这些冰质天体活动的主要驱动力，但控制潮汐力如何使不同内部层发生变形以及通过潮汐摩擦产生热量的机制，仍然受到很大限制。由于潮汐力随轨道特征（与中心行星的距离、偏心率、倾角）而变化，在地质时间尺度上，潮汐加热对内部热收支的贡献可能会发生很大变化。在某些情况下，潮汐产生的热量会导致内部融化和表面出现各种形式的活动。即使在没有大量热量产生的情况下，潮汐变形也可用于探测内部结构，冰卫星的潮汐响应对其水圈结构非常敏感。在本文中，我们回顾了计算构成冰质天体的不同层中潮汐变形和耗散的方法。在总结了潮汐变形的主要原理以及用于模拟粘弹性潮汐响应的不同流变模型之后，我们描述了在以岩石为主的核心、地下海洋和冰壳中预期的耗散过程，并强调了潮汐加热在热演化和活动方面的潜在影响。我们最后预测了未来对木星和土星卫星的探测任务所收集的数据将如何用于限制它们的潮汐响应以及对过去和当前活动的影响。
