Radial interplanetary fields at Comets and Mars

彗星和火星的径向行星际场

• 批准号: 2878079
• 金额: --
• 依托单位: Northumbria University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2878079
• 关键词: Radial; interplanetary; fields; Comets; Mars

Objects in the solar system are embedded in the solar wind and how they interact with it depends on their atmosphere and magnetic fields. Bodies without a global magnetic field, like Mars and comets, develop an induced magnetosphere. This region is an ideal plasma laboratory consisting of different ion species and dust particles that can be explored by spacecraft. Understanding the environment is crucial for future human exploration and our understanding of the solar system.One of the main parameters determining the shape of the interaction region is the direction of the interplanetary magnetic field (IMF). Most models assume a unified "standard" direction of the field, which often gives good results. However, the IMF is highly variable, and a large part of cases is not covered in literature.Plasma observations at both Mars and comet 67P/Churyumov-Gerasimenko recently showed unusual wave and particle activity that was not covered by the standard models, and which were attributed to a radial IMF configuration. For these cases the environment can change completely, and ion escape and acceleration rates are dramatically different. This has consequences for planetary atmospheric models and cometary tail observations that are poorly understood. This is a knowledge gap that should be filled before the upcoming mission Comet Interceptor will encounter a comet and take multi-point measurements in this environment for the first time.The key to understanding the environment under these special conditions is to relate existing numerical and analytical models to the observations and build new models that better describe the non-standard cases.

太阳系中的物体被嵌入太阳风中，它们如何与太阳风相互作用取决于它们的大气层和磁场。没有全球磁场的天体，比如火星和彗星，会形成一个感应磁层。这个区域是一个理想的等离子体实验室，由不同的离子种类和尘埃粒子组成，可以被宇宙飞船探索。了解环境对未来的人类探索和我们对太阳系的理解至关重要。决定相互作用区域形状的主要参数之一是行星际磁场的方向。大多数模型假设场的统一“标准”方向，这通常会得到很好的结果。然而，国际货币基金组织是高度可变的，很大一部分案例没有在文献中涉及。最近在火星和67P/Churyumov-Gerasimenko彗星上的等离子体观测显示，标准模型没有涵盖不寻常的波和粒子活动，这归因于径向IMF结构。在这些情况下，环境可以完全改变，离子逃逸和加速速率也会有很大的不同。这对我们知之甚少的行星大气模型和彗星尾巴观测产生了影响。在即将到来的彗星拦截器任务遇到彗星并首次在这种环境下进行多点测量之前，这是一个应该填补的知识空白。理解这些特殊条件下的环境的关键是将现有的数值和分析模型与观测联系起来，并建立更好地描述非标准情况的新模型。