A Consolidated Grant Proposal for Solar System Research at the University of Leicester (2016-2019)

We propose a world-class programme of research that focuses on two main areas of study concerned with our solar system. The first involves study of the outer environments of the planets where the gas is in the plasma (ionized) state, such that it not only feels the gravitational pull of the planet, but also interacts strongly with its magnetic field. In the second area we seek to study the origin and development of solar system bodies, and the impact on the evolution of life, through detailed examination of the composition of samples from comets, asteroids, and Mars, that are returned by spacecraft for study at Earth, or examined in situ during planetary exploration missions. Previous work in the first area shows that the outer environments of the planets vary widely, determined by the interaction with the plasma wind 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 11-year 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 orbiting close in. We will use spacecraft data to study Mercury close to the Sun that has a magnetic field but almost no atmosphere (MESSENGER mission), Mars further away that has an atmosphere but no strong magnetic field to prevent its erosion by the solar wind (Mars Express and MAVEN), and Earth at intermediate distances having both an atmosphere and a magnetic field (using data from a number of missions including the auroral-imaging IMAGE and Polar satellites, and the Iridium satellite constellation). We will also study the strongly magnetized giant planets Jupiter, Saturn, and Uranus, using data from the new 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 atmosphere or surface on the inside. In a related project we also propose to develop a flight-ready compact low mass ultraviolet imager that can be used to study the auroras at Earth and elsewhere, as well as for wider applications. Research on the origins and evolution of solar system bodies builds on the expertise we have developed in the microanalysis of micron-sized samples of planetary materials, through a unique combination of electron microscopy and synchrotron-based X-ray spectroscopy. Such techniques are essential due to the small amounts of material returned from solar system bodies such as S-class asteroid Itokawa (Hayabusa mission) and Comet 81P/Wild2 (Stardust mission), studies of both forming part of our programme. Analysis of such grains offers the chance to provide a direct comparison to known primitive meteorite types and to reveal the processes that shaped the earliest stages of the solar system. We will also use these techniques to study a recently discovered Martian meteorite which will allow us to constrain the thermal and water-rock interaction history in a sample of Martian impact regolith for the first time. In a related area we also propose to develop an astrobiology instrument that will be able to detect organic compounds and minerals. The primary aim will be to build a miniaturized analytical instrument that can be configured for both in-situ and remote analysis and will be suitable for inclusion in future planetary exploration missions such as those planned by NASA and ESA.