A Consolidated Grant Proposal for Solar and Planetary Science at the University of Leicester, 2022 - 2025

我们提出了一个世界级的研究计划，重点研究与我们太阳系有关的三个主要领域。第一种方法是研究气体被电离的行星的外部环境，这样气体不仅能感受到行星的引力，还能与行星的磁场和电场产生强烈的相互作用。在第二个领域，我们试图研究太阳系天体的起源和演化，通过检查小行星、球粒陨石和月球样本的材料，以及通过基于实验室的水星类似物的x射线荧光探测。第三个区域将使用詹姆斯·韦伯太空望远镜（JWST）和地面天文台的光谱来探索冰巨星天王星和海王星的平流层和对流层。先前在第一个领域的工作表明，行星的外部环境变化很大，这是由它们与外部太阳不断吹来的等离子体的相互作用以及与内部行星及其卫星的相互作用决定的。太阳风很容易爆发，可能导致地球上的磁暴和明亮的极光，并且在太阳周期和与太阳的距离上变化强烈。它与行星的相互作用取决于行星是否被磁化，是否有大气层，是否有活跃的卫星。我们将利用信使号的数据研究靠近太阳的水星，这颗行星有磁场，但几乎没有大气层；在离太阳更远的火星上使用航天器星座，火星有大气层，但没有强大的磁场来防止太阳风的侵蚀；并结合地球上的多航天器和地面仪器，在中距离上既有大气层又有磁场。我们还将利用朱诺号木星探测器和卡西尼号土星探测器的数据，结合哈勃太空望远镜的紫外波长和大型地面望远镜的红外波长对极光的观测，研究强磁化的巨行星木星和土星。极光是由在外层环境和上层电离大气之间流动的大规模电流引起的，这些电流在这些区域之间传递力。总体重点将放在复杂的物理过程上，这些物理过程将外部的太阳风、行星周围的磁场（如果有的话）和内部的行星大气或表面耦合在一起。在第二个领域，实验室研究，我们将分析由隼鸟2号任务从c级小行星龙宫带回的物质。我们将对阿波罗月球风化颗粒和最近独特的碳质球粒陨石进行补充分析，以建立对空间风化和c级小行星母体过程的新认识。该项目建立在我们在行星材料微分析方面的领先专业知识的基础上，通过ePSIC和UoL的电子显微镜以及基于同步加速器的x射线光谱学。针对水星的实验室工作将集中在MIXS地面参考设施上，这是一个专门建造的系统，可以对x射线荧光进行详细分析，使用x射线或电子源诱导，用于定制的表面类似物。这个实验室设施将使我们能够利用来自BepiColombo任务的MIXS数据来扩展我们的科学计划，无论是在水星的全球和局部尺度上，还是在产生与电子轰击相关的重要x射线荧光的夜侧磁层-表面相互作用方面。最后一个主题是利用莱斯特大学在JWST上的保证时间巨行星计划的领导地位，利用冰巨星天王星和海王星的MIRI光谱图，结合地面观测计划，了解平流层环流、光化学和对流层气象如何塑造亚巨星大小的世界的大气。

We propose a world-class programme of research that focuses on 3 main areas of study concerned with our solar system. The first involves study of the outer environments of the planets where the gas is ionised, such that it not only feels the gravitational pull of the planet, but also interacts strongly with its magnetic and electric fields. In the second area we seek to study the origin and evolution of solar system bodies, through examination of materials from asteroid, chondrite and lunar samples, and through laboratory-based exploration of X-ray fluorescence from Mercury analogues. The third area will employ spectroscopy from the James Webb Space Telescope (JWST) and ground observatories to explore the planetary stratospheres and tropospheres at the ice giants Uranus and Neptune.Previous work in the first area shows that the outer environments of the planets vary widely, determined by the interaction with the plasma that blows continuously from the Sun on the outside, and the interaction with the planet and its moons on the inside. The solar wind is prone to outbursts that can lead to magnetic storms and bright auroras at Earth, as well as varying strongly over the solar cycle, and with distance from the Sun. Its interaction with the planets then depends on whether the planet is magnetised, has an atmosphere, and has active moons. We will use MESSENGER data to study Mercury close to the Sun, a planet that has a magnetic field but almost no atmosphere; use the constellation of spacecraft at Mars, more distant from the Sun, which has an atmosphere but no strong magnetic field to prevent its erosion by the solar wind; and combine multi-spacecraft and ground instrumentation at Earth, at intermediate distances having both an atmosphere and a magnetic field. We will also study the strongly magnetized giant planets Jupiter and Saturn using data from the Juno mission at Jupiter and Cassini at Saturn, combined with observations of the auroras at ultraviolet wavelengths using the Hubble Space Telescope and at infrared wavelengths using large ground-based telescopes. Auroras are caused by large-scale electric currents flowing between the outer environments and the upper ionized atmospheres, which communicate force between these regions. Overall emphasis will be on the complex physical processes that couple the solar wind on the outside, the magnetic field surrounding the planet (if any), and the planetary atmospheres or surface on the inside.In the second area, laboratory studies, we will analyse material returned from C-class asteroid Ryugu by the Hayabusa2 mission. We will make complementary analyses on Apollo lunar regolith grains and recent, unique carbonaceous chondrite falls to build a new understanding of space weathering and C-class asteroid parent body processes. This project builds on the leading expertise we have in the microanalysis of planetary materials, through electron microscopy at ePSIC and UoL, and synchrotron-based X-ray spectroscopy. Laboratory work focused on Mercury will centre on the MIXS Ground Reference Facility, a purpose-built system to allow detailed analysis of X-ray fluorescence, induced using an X-ray or electron source, for bespoke surface analogues. This laboratory facility will uniquely allow us to expand our science programme using the MIXS data from the BepiColombo mission, both in relation to the dayside surface composition goals at global and local scales on Mercury, and in terms of the nightside magnetosphere-surface interaction which produces a significant X-ray fluorescence associated with electron bombardment.The final theme leverages Leicester's leadership of the guaranteed-time giant planets programme on the JWST, exploiting MIRI spectroscopic maps of the Ice Giants Uranus and Neptune, combined with a ground-based observation programme, to understand how stratospheric circulation, photochemistry, and tropospheric meteorology shape the atmospheres of sub-giant-sized worlds.