Magnetic Field Investigations of Mars and Mercury

火星和水星的磁场研究

• 批准号: RGPIN-2016-03710
• 负责人: Johnson, Catherine
• 金额: $ 6.38万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633667
• 关键词: Magnetic; Field; Investigations; Mars; Mercury

The proposed research program aims to understand the magnetic field environments of Mercury and Mars. At Mercury and Mars, magnetic fields arise from “internal sources” such as fluid motions in the metallic core and/or magnetization of crustal rocks, and from “external sources” such as current systems generated high above the planet’s surface. The resulting environments provide fundamental clues about each planet’s interior, its evolution and its interaction with the solar wind (the stream of charged particles that flows outward from the sun). Past and present interactions with the solar wind have important consequences. For example, the remarkable history of surface water on Mars is tied partly to the resilience of the planet’s atmosphere against erosion by the solar wind. In contrast, on Mercury, direct bombardment of the surface is possible but not yet fully quantified. This process can modify the surface (space weathering), and eject atoms and molecules to form a tenuous atmosphere (exosphere). Finally, time-variations in external magnetic fields (e.g., driven by the solar wind) can generate electrical currents in the planetary interior that produce secondary magnetic fields. Such fields are a unique probe of interior electrical conductivity structure.

拟议中的研究计划旨在了解水星和火星的磁场环境。在水星和火星上，磁场产生于“内部来源”，如金属核心的流体运动和/或地壳岩石的磁化，以及“外部来源”，如行星表面高处产生的电流系统。由此产生的环境为每颗行星的内部、演化及其与太阳风（从太阳向外流动的带电粒子流）的相互作用提供了基本线索。过去和现在与太阳风的相互作用有着重要的影响。例如，火星表面水的非凡历史在一定程度上与火星大气层抵御太阳风侵蚀的韧性有关。相比之下，在水星上，直接轰击表面是可能的，但尚未完全量化。这个过程可以改变表面（太空风化），并喷出原子和分子形成稀薄的大气层（外逸层）。最后，外部磁场的时间变化（例如，由太阳风驱动）可以在行星内部产生电流，从而产生二次磁场。这种场是一种独特的内部电导率结构探针。