Planetary Science at Oxford Physics 2019

Lead Research Organisation: University of Oxford
Department Name: Oxford Physics

Abstract

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.

Planned Impact

Our work is at the cutting edge of modern planetary science and will bring benefits to the UK through public engagement, scientific advancement and industrial collaboration as outlined below.
1. Public Engagement and Outreach: Our group has a very strong track record in public outreach and engagement including participating in events such as "Stargazing Oxford", "Pint of Science" and the Royal Society's Partnership scheme and Summer Exhibition. Typically, the largest public interest in space exploration occurs at crucial moments in a mission's lifetime, e.g. the extended science mission for ESA/NASA's Juno mission, launch of ESA's Jupiter Icy Moons Explorer (JUICE) mission in 2022, rendezvous and sampling for NASA/OSIRIS-REx mission (2019-2022) at asteroid Bennu, and the James Webb Space Telescope (2019 - ). We will work with local organisations to arrange outreach events to mark these key stages in the missions we are involved with. We will continue to contribute to the department's efforts in engaging diverse audiences through targeted programmes and community events and are working to reach schools in Oxford with the lowest progression rates to university. This work aligns with STFC's mission of "Improving our reach with diverse audiences".
2. Analysis Techniques: The techniques we are developing for better exploiting Solar System planet observations will have potential impacts in other areas also. We are a member of an academic partnership with the UK Met Office, which will allow advances we make in atmospheric circulation modelling to be made available to Met Office researchers enabling them to be applied in weather forecasting and climate change prediction. The advanced retrieval techniques we are developing with our radiative transfer and retrieval model, NEMESIS, have the potential to change quite radically the way we think of our place in the Universe since they can be applied not only to Solar System planets, but also to the emerging field of exoplanetary science.
3. Novel Spacecraft Instrumentation: Our space instrument development activity involves collaboration with several UK industrial partners, where we are using technologies we have developed for planetary science instrumentation to enable a new class of radiometers for small Earth observation spacecraft. The surfaces theme includes the development of a compact infrared spectrometer and we are currently in early discussions with Oxford's technology transfer office (Oxford University Innovations Ltd) regarding possible commercial uses for this instrument for future Earth observation and ground-based applications.
4. Laboratory Surface Characterisation: The proposed upgrade to our space environment spectrogoniometer will enable a much wider user group from both academia and industry to gain benefit from using this facility. Example applications include carrying out specialist spectroscopic characterisation of high emissivity coatings or spacecraft components at multiple emission and reflection angles.
5. Building Connections: The planetary group coordinates the Oxford Space Research Network that brings together groups within the University with space instrumentation and technology interests. Our Network is an important route for connecting and disseminating our work to the national and international space sector. Preparation for future missions (especially in ESA's Cosmic Vision programme) helps to inform and enable involvement by UK companies.
6. Citizen Science: For our work on giant planet atmospheres the increasing ability of amateur observers to provide background monitoring of events is a hugely exciting new area of planetary science. Amateur astronomers were responsible for the detection of several planetary storms in the last few years, which led to professional programmes and resulting publications. Such involvements also give rise to increased engagement by amateur observers and the wider public/media

Publications

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