Solar System Planetary Science at Oxford 2016-2019

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 soil structure. We have four main projects that are complementary.

1. The first project explores the dynamic atmospheres of Ice Giants, Uranus and Neptune, by studying seasonal changes during a period when Uranus is changing rapidly following its Northern Spring Equinox in 2007, and comparing its atmosphere with the dynamic, turbulent atmosphere of Uranus' sister planet, Neptune. A key part of our study is to understand the generation and evolution of convective storm clouds now regularly seen on both planets. We will improve the retrieval techniques used to interpret such data and couple these with other information, such as models of cloud condensation, to yield more self-consistent solutions. By exploring the thermal balance in these atmospheres we will look for imbalances that might reveal the details of dynamical or condensation processes. This project has overlap with Projects 3 and 4.

2. Our second project builds on our world-class laboratory measurement programme to understand planetary, asteroid and comet surfaces. We will determine the ways in which visible and infrared light is both emitted and reflected by different surfaces, under conditions equivalent to those in space with extreme variations of solar heating. These data will be crucial to interpret observations made by NASA's OSIRIS-REx asteroid sample return mission, an ongoing lunar programme, and the Jovian satellite component of Project 3.

3. Our third project explores the interconnections in giant planet systems and builds upon our existing participation with the NASA Cassini mission. It will help us better understand the atmospheric processes linking the interior circulation of Jupiter and Saturn with the weather layer and upper atmosphere of these planets and also to develop techniques to explore environmental conditions on Jupiter's satellites, preparing the way for future observations with NASA's JWST and ESA's JUICE mission. In particular we seek to map Jupiter's evolving atmosphere with ground-based observations in support of the NASA Juno mission to Jupiter (2016-2017). This project will use some of the same tools developed in Project 1 and interpretation of the observations will be aided by the work described in Projects 2 and 4.

4. Our final project examines the atmospheric dynamics of Gas and Ice Giant planets by improving the dynamical modelling of the atmospheric circulation of the Gas Giants (Jupiter and Saturn) and also, in particular, the Ice Giants (Uranus and Neptune). This will help us better understand how the wind structure of these planets is formed and maintained and also determine the role played by clouds and convection driven by condensation of atmospheric water vapour in their climates. This work will help interpret the observations described in Projects 1 and 3.

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.

1. Public Engagement: Our group has a very strong track record in public outreach and engagement. Our involvement with several space missions gives us valuable public engagement opportunities, since the largest public interest in space missions tends to occur at crucial moments in a mission's lifetime. Crucial periods foreseen during this grant period include the end of the NASA Cassini mission (2017), the NASA Juno mission (2016-2017), the NASA OSIRIS-Rex mission (2016-2019) and the launch of NASA's James Webb Space Telescope (2018). These events present exciting opportunities to explain and share our scientific discoveries with the general public and students, and to encourage greater participation, enthusiasm and interest in science and technology.

2. Analysis Techniques: The techniques we are developing for better exploiting solar system planet observations will have potential impacts in other areas also. We have recently entered into a new 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 combining technology we have developed for planetary science instrumentation with subsystems from our partners to enable a new class of radiometers for small Earth observation spacecraft. For example, in July 2014 we celebrated the launch and successful commissioning of the first of these, the Compact Modular Sounder instrument, on the UK TechDemoSat-1 mission in collaboration with RALSpace. The surfaces theme includes the development of a compact infrared spectrometer and we are currently in early discussions with Oxford's technology transfer office (Isis Innovations Ltd) regarding possible commercial uses for this instrument for future Earth observation and ground based applications.

4. Laboratory Surface Characterization: The proposed upgrade to our space environment spectrogoniometer will enable a much wider user group to gain commercial benefit from using this facility, including, for example, by carrying out specialist spectroscopic characterization of high emissivity coatings at multiple emission and reflection angles.

5. Building Connections: Our involvement in the continued preparation for future missions (especially in ESA's Cosmic Vision programme) will inform and enable involvement by UK companies. Current examples include engagement with a major aerospace company regarding spacecraft and mission designs for a Uranus orbital spacecraft and discussions with a UK company to provide detectors for a Saturn probe mission camera (both proposed CV M4 missions).

6. Citizen Science: The increasing ability of amateur observers to provide background monitoring of atmospheric events in planetary atmospheres 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 target-of-opportunity programmes and significant resulting publications. Such involvements, however, also give rise to increased engagement by amateur observers, interest from the wider public and coverage by the media.