Investigating the thermal histories of terrestrial planets using 3D numerical models

气态巨星的类地行星和大卫星都展示了它们不断演化的内部的表面表现。它们内部活动的驱动力是热量。尽管其中一些热量是太阳系早期历史中行星形成和陨石撞击年轻行星时产生的残余热量，但大部分热量来自至今仍在存在的来源和过程。这些热源中最重要的是行星地幔(环绕着固体行星金属核心的厚厚的岩石壳)中的铀、钍和钾产生的辐射加热。木星(木卫一和木卫二)和水星的两颗卫星(木卫一和欧罗巴)以及水星的另一个重要热源是潮汐加热，这分别是由于与木星和太阳相关的引力。所有这些热量被困在行星地幔中的结果是一种被称为地幔对流的过程，这种现象允许构成岩石地幔的硅酸盐岩石在地质时间尺度上流动，就像慢煮的食用油一样。地幔对流是大多数固体行星和卫星自形成以来一直在进行的过程，为了研究地幔对流，我们可以使用复杂的计算机模型来求解具有热硅酸盐岩石性质的流体中的对流方程。因此，我们可以研究影响行星演化的众多自然过程的起源。例如，在地球上，内部运动导致地表运动(我们称之为板块构造和大陆漂移)，研究地幔对流有助于深入了解火山活动、地震和造山的过程。此外，地幔对流影响行星磁场、表面地形、重力场，对于地球而言，还影响矿物和碳氢化合物资源的形成以及地球的气候系统，从而影响环境和生物演化的周期。因此，对这些学科的研究揭示了地幔对流的某些表现，反过来，我们对地幔对流的不断发展的理解可能会影响对地球和行星科学中各种领域的传统观点。

The terrestrial planets and large moons of the gas giants each exhibit surficial manifestations of their evolving interiors. The driving force for their internal activity is heat. Although some of the heat is a remanent of that generated during planetary formation and the bombardment of the young planets by meteorites during the early history of the solar system, the majority results from sources and processes still in place today. The most important of these heat sources is radiogenic heating from Uranium, Thorium and Potassium in planetary mantles (the thick rocky shells surrounding the metallic cores of the solid planets). Another important source of heat in two of the the satellites of Jupiter (Io and Europa) and possibly Mercury is tidal heating due to the gravitational forces associated with Jupiter and the Sun, respectively. The result of all of this heat being trapped in a planetary mantle is a process called mantle convection, a phenomenon that allows the silicate rocks comprising a rocky mantle to flow, over geologic time scales, like cooking oil on a slow boil. In order to study mantle convection, a process that has been ongoing in most of the solid planets and moons since their formation, we can employ sophisticated computer models that solve the equations governing convection in fluids with the properties of hot silicate rocks. As a result we can study the origin of numerous natural processes effecting planetary evolution. For example, on Earth, internal motion results in surface motion (what we call plate tectonics and continental drift) and studying mantle convection provides insights into the processes responsible for volcanism, earthquakes and mountain building. In addition, mantle convection influences planetary magnetic fields, surface topography, gravitational fields, and, again in the case of the Earth, the formation of mineral and hydrocarbon resources and the planet's climatic system, thus influencing cycles of environmental and biological evolution. Accordingly, the study of each of these disciplines reveals some expression of mantle convection and, conversely, our evolving understanding of mantle convection may affect conventional views of a diverse range of fields in the Earth and planetary sciences.