Planetary Science at Oxford Physics 2019

行星物理学的建议范围从研究巨行星的大气层到研究无气天体（如小行星）的反射率和热特性，这是研究这些天体的主要方法。该计划概述了一项协调一致的努力：1)测量和了解太阳系内外巨大行星大气中的流体循环、云凝结和光化学；2)测量和解释无空气行星体的光谱，以更好地了解它们的起源、组成和风化层结构。我们有四个互补的主要项目。项目1：朱诺号任务的最新结果表明，木星（可能还有土星）复杂的带状大气环流与行星半径相比既不是很深，也不局限于一个较浅的“天气层”。这就留下了许多关键问题的答案，这些问题涉及它们的气象学的动力学起源以及由此产生的热量和物质示踪剂在这些标志性和原型行星体内的传输。在这个项目中，我们将测试和评估木星和土星大气环流主要特征的可能动力机制，结合对卡西尼号、旅行者号、朱诺号和其他航天器观测到的风和热结构的创新分析，以及最先进的木星和土星深层天气层的全球数值环流模型。项目2：巨行星大气中的云是如何形成的？它们是由什么构成的，又是如何开始的？在这个项目中，我们将把近红外（近红外）反射测量、热红外发射观测和基础建模联系起来，探索富氢太阳系巨行星的云形成。这最终将有利于理解太阳系行星和系外行星的云。项目3：原始小行星（通常被认为是C型和b型小行星）为太阳系的形成和演化提供了重要线索。在这个项目中，由于我们是英国唯一的合作研究者和参与科学家，我们将使用美国宇航局OSIRIS-REx任务的数据来研究原始小行星Bennu，为2020年对其表面进行采样做准备。作为该任务科学团队的一员，利用我们定制的实验室和数值模拟能力，我们的工作将把返回的样本置于地质背景下，并帮助确定本努在太阳系小行星种群的更广泛背景下的位置。项目4：热红外（TIR）遥感测量可用于通过光谱和温度测绘来确定无空气物体的成分和物理性质。包括美国宇航局月球勘测轨道器（LRO）和OSIRIS-REx在内的任务正在获取表面温度数据集，要正确解释这些数据需要新的实验室测量。该项目通过使用和升级独特的实验设备——牛津空间环境角计，解决了热发射随观测角度、表面粗糙度和孔隙度的变化，以进行有针对性的实验室测量，最大限度地从这些新的和未来的数据集中获得回报。

This proposal in planetary physics ranges from studying the atmospheres of the giant planets through to studying the reflectance and thermal properties of airless bodies such as asteroids, which are the primary ways in which these bodies can be studied. The programme outlines a coordinated effort to: 1) measure and understand the fluid circulations, cloud condensation and photochemistry in giant planet atmospheres, both within the Solar System and beyond; and 2) measure and interpret the spectra of airless planetary bodies to better understand their origins, composition and regolith structure. We have four complementary main projects. Project 1: Recent results from the Juno mission have indicated that the complex, zonally banded atmospheric circulation of Jupiter (and probably Saturn) is neither very deep compared to the planetary radius, nor confined solely to a shallow 'weather layer'. This leaves unanswered a host of key questions concerning the dynamical origin of their meteorology and the resulting transport of heat and material tracers within these iconic and prototypical planetary bodies. In this project, we will test and evaluate possible dynamical mechanisms for energizing the principal features of the atmospheric circulations of Jupiter and Saturn, using a combination of innovative analyses of the observed wind and thermal structure from Cassini, Voyager, Juno and other spacecraft, and a state- of-the-art global numerical circulation model of the deep weather layers of Jupiter and Saturn. Project 2: How do clouds form in the atmospheres of the Giant Planets? What are they made of and how are they initiated? In this project we will link near-infrared (near-IR) reflection measurements, thermal-IR emission observations and fundamental modelling to explore cloud formation in hydrogen-rich Solar System Giant Planets. This will ultimately benefit the understanding of clouds in both Solar System planets and exoplanets.Project 3: Primitive asteroids (usually assumed to be C- and B-type asteroids) hold important clues to the formation and evolution of the Solar System. In this project, enabled by our roles as the UK's only Co-Investigator and Participating Scientist, we will use data from NASA's OSIRIS-REx mission to study primitive asteroid Bennu in preparation for sampling of its surface in 2020. As part of the mission's science team, and using our bespoke laboratory and numerical modelling capabilities, our work will place the returned sample into geologic context and also help determine Bennu's place in the wider context of the Solar System's asteroid populations. Project 4: Remote sensing measurements in the thermal infrared (TIR) can be used to determine the composition and physical properties of an airless body through spectroscopy and temperature mapping. Surface temperature datasets are being acquired by missions including NASA's Lunar Reconnaissance Orbiter (LRO) and OSIRIS-REx, and to interpret them correctly requires new laboratory measurements. This project addresses how thermal emission varies with observation angle, surface roughness and porosity by using and upgrading a unique experimental facility, the Oxford Space Environment Goniometer, to make targeted laboratory measurements to maximise the return from these new and future datasets.