Hermean Magnetosphere and Exosphere

在过去的十年中，关于水星磁层中等离子体和磁场结构的实验信息的质量有了很大的提高。自2011年3月信使号被送入水星轨道以来，直到2015年4月30日，信使号在4104圈后完成了任务，该航天器已经传输了大约14TB的数据，包括磁场矢量测量。然而，在缺乏可靠的定量估计的情况下，行星磁场与太阳风等离子体流相互作用的许多特征要么是未知的，要么只是笼统地明确的。其中，人们可以指出一些简单的问题，如穿透磁层的行星际磁场的相对大小，经过行星的磁化太阳风等离子体流引起的势降的平均大小和范围，以及磁层夜间磁尾的形成条件、结构和相对长度。行星磁场是否减缓或加速了对外圈的侵蚀，以及外圈以多快的速度补充从表面溅射出来的中性粒子，这些问题仍然悬而未决。开发赫米恩磁层和外磁层的定性模型，并通过与信使号的结果进行比较来改进它，将使我们的项目至少部分地回答这些问题。

During the past decade the quality of experimental information on plasma and magnetic field structure in Mercury's magnetosphere has substantially improved. Since March 2011, when MESSENGER was inserted into the Mercury’s orbit and until April 30, 2015 when its mission was completed after 4104 orbits the spacecraft had transmitted approximately 14 TB of data, including magnetic field vector measurements. Nevertheless, many features of interaction of planetary magnetic fields with the solar wind plasma flow remain either unknown or clear only in general terms in the absence of reliable quantitative estimates. Among these, one can point out simple questions such as the relative magnitude of the interplanetary magnetic field penetrating the magnetosphere, the average magnitude and range of potential drop arising due to magnetized solar wind plasma flow past the planet, and conditions for formation, structure and relative length of the magnetotail on the nightside of the magnetosphere. The questions whether the planetary magnetic field slows down or accelerates the erosion of the exosphere and at what rate the exosphere is replenished with neutral particles sputtered from the surface remain open. Developing qualitative models of the Hermean magnetosphere and exosphere and refining it by comparing with the results of MESSENGER will allow our project to at least partially answer these questions.