Planetary Science at Oxford Physics 2022

行星物理学中的这一提议涵盖了从研究“冰巨人”巨型行星的大气层到研究小行星等无空气天体的反射率和热学性质，这是研究这些天体的主要方法。该方案概述了一项协调工作，以：1)测量和了解太阳系内外巨大冰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的光谱，以更好地了解它们的来源、组成和浮层结构。我们有四个相辅相成的主要项目。项目1：太阳系中所有巨行星复杂的带状大气环流似乎延伸到与行星半径相比既不是很深的深度，也不只限于较浅的“天气层”。这就留下了一系列悬而未决的问题，涉及它们气象学的动力来源、云和阴霾的形成和组织以及由此产生的热量和物质示踪剂的运输。在这个项目中，我们将测试和评估可能的动力学机制，以激发相对未被探索的冰巨星、天王星和海王星的大气环流的主要特征。我们的方法将结合对旅行者号航天器观测到的风和热力结构的创新分析、地面观测和潜在的JWST，以及两个行星深层气象层的新的最先进的全球数值环流模型。项目2：天王星和海王星这两个“冰巨人”由于与其他恒星的“小海王星”有关而引起越来越多的兴趣，并迅速改进地面和空间望远镜观测。然而，目前尚不清楚这些冰巨人的大气中的云是如何形成的，它们的形成与整个颠覆的大气环流有何关系，以及明亮的、离散的暴风云特征与大气动力学和热异常有何联系。在这个项目中，我们将把近红外(近红外)反射测量与同时进行的热红外发射观测联系起来，以探索富氢太阳系冰巨行星中的云形成，并用基本模型分析这些观测结果。这最终将有助于理解太阳系行星和系外行星中的云。项目3：原始小行星(通常被假设为C型和B型小行星)掌握着太阳系形成和演化的重要线索。在这个项目中，由于我们作为此次飞行任务的联合调查员和样品分析小组的成员，我们将使用NASA的OSIRIS-REX任务的数据来研究原始小行星Bennu，为在赠款期间测量样品做准备。作为此次任务科学团队的一部分，并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中，并帮助确定本努在太阳系小行星种群的更广泛背景中的位置。项目4：热红外遥感测量可用于通过光谱分析和测温图确定无空气物体的组成和物理性质。包括NASA的月球勘测轨道器(LRO)和即将到来的月球着陆器和轨道器在内的任务正在获取表面温度数据集，要正确地解释它们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测角仪，进行有针对性的实验室测量，以最大限度地利用这些新的和未来的数据集，解决热发射如何随观测角度、表面粗糙度和孔隙度的变化而变化。

This proposal in planetary physics ranges from studying the atmospheres of the 'Ice Giants' 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 ice 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: The complex, zonally banded atmospheric circulations of all of the giant planets in the Solar System appear to extend over depths that are neither very deep compared to the planetary radius, nor confined solely to a shallow 'weather layer'. This leaves unanswered a host of questions concerning the dynamical origin of their meteorology, the formation and organization of clouds and hazes and the resulting transport of heat and material tracers. In this project, we will test and evaluate possible dynamical mechanisms for energizing the principal features of the atmospheric circulations of the relatively unexplored 'Ice Giant' planets, Uranus and Neptune. Our approach will use a combination of innovative analyses of the observed wind and thermal structure from the Voyager spacecraft, ground-based observations and potentially the JWST, together with a new state-of-the-art global numerical circulation model of the deep weather layers of both planets.Project 2: Uranus and Neptune, the 'Ice Giants', are of increasing interest due to their relevance to the 'mini-Neptunes' being discovered about other stars and rapidly improving ground-based and space-based telescope observations. However, it remains unclear how clouds form in the atmospheres of these Ice Giants, how their formation is related to the overall overturning atmospheric circulation, and how bright, discrete storm cloud features are linked to atmospheric dynamics and thermal anomalies. In this project we will link near-infrared (near-IR) reflection measurements with thermal-IR emission observations taken contemporaneously to explore cloud formation in hydrogen-rich Solar System Ice Giant Planets and analyse these observations with fundamental modelling. 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 a Co-Investigator on the mission and members of the sample analysis team, we will use data from NASA's OSIRIS-REx mission to study primitive asteroid Bennu in preparation for measurements of the sample during the grant period. 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 upcoming lunar landers and orbiters, 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.