The formation and evolution of the Solar System

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The environment in which the early solar system formed can be studied using meteorites that date from that time. This is a proposal to learn more about how the planets formed from a disk of dust and gas. We propose five specific projects:Project A. Rounded spheres called chondrules are common in many meteorites. They formed during a flash heating event in the early solar system. Using newly developed, highly precise, Mg isotope techniques, we propose to determine the relative age of chondrules to a precision not possible before. We want to test a hypothesis that the heating they experienced was a necessary step in planetary accretion, perhaps triggering the accretion process. This has been suggested because the physical and isotopic properties of chondrules suggest they formed at high dust pressures that may have made accretion inevitable. Project B. The study of water in the solar system is fundamental to understanding the evolution of planetary bodies. It is clear the minerals interacted with water to produce hydrated materials. The question is where did that hydration take place - primarily in the parent body of the minerals or in a combination of the solar nebula and parent body? This is important to determining the compositions and locations of reservoirs of H2O available in the early solar system. Project C. As stated on the STFC website, the UK Cosmochemistry Analytical Network is an integrated scheme for the development of new analytical technologies for the laboratory analysis of extraterrestrial material, particularly dust samples returned directly to Earth from space missions. With applications ranging from the physics of stellar nucleosynthesis to the origins of life, the UK-CAN is an essential complement to space-based planetary missions and to several areas of ground based observational astronomy. The need to develop new instrumentation is driven by the imminent return of samples obtained by space missions, as well as by the nature of extraterrestrial samples. Interstellar grains isolated from primitive meteorites range in size from a few microns to a few nanometres (organics and nanodiamonds). Only the largest can be analysed individually with present technology and analyses are limited to the major isotopes. The international community is gearing up towards a new era of sample analysis, stimulated by the return of samples from GENESIS in 2004, STARDUST in 2006 and MUSES-C in 2007, and the potential return of soil from Mars. The UK institutions with major expertise and a proven track record of excellence in the laboratory analysis of extraterrestrial samples are the National History Museum, the Open University and the University of Manchester and these institutions form the core of UK-CAN. Project D. The chemistry of the minerals that make up extraterrestrial materials lead to a better understanding of the environment in which the planets formed in the solar system. Analysing element composition in situ allows further understanding of the physical processes that affected the rocks. In Project D, the applicant will study sulphide nodules from iron meteorites in an effort to understand the thermal environment of the solar system prior to planet formation and will use the same data set to explore the physical process involved in the crystallisation of cores of planets and planetesimals. Project E. Meteorites often contain a fine grained matrix that has not been well studied, because its sub-micron grain size prohibits most analytical techniques. We propose to undertake pathfinder experiments to analyse matrix grain by grain. The aim will be to determine the origin of these grains, and their physical and chemical history. We will then compare them to their analogues: circumstellar dust around young stellar objects.