Defining the thermal environment of the proto-planetary circumsolar disk: Continuation

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What were conditions like when the planets were being formed, and what were the major factors that affected their formation? What was the solar system made from? How likely is it that similar processes acted to form planets such as the Earth and Mars around other stars? What can we learn about the possible existence of terrestrial-type planets elsewhere in the galaxy from studying the origins of our own planetary system? These are a few of the questions that we hope to help answer in the proposed research. It is thought that the solar system was formed from a nebula - a cloud of dust and gas. The composition of that material is not known, but we do know that a section of the nebula collapsed under gravity, formed a disk around the young Sun (a so-called proto-planetary disk), and underwent processing at a range of temperatures, in a wide variety of environments, before clumping together to make planets. We're lucky in having a collection of samples that date from this earliest period in solar system history. Primitive meteorites are amongst our only samples of the proto-planetary nebula. In the most primitive meteorites, the mineralogy and chemistry of this material suggests that it escaped subsequent thermal and aqueous alteration within the asteroid. As such, it offers a unique window on conditions in the disk prior to accretion of the first solids. Our knowledge of the thermal environment of the early solar system comes from chemical and mineralogical analyses of these rare meteorites. But those models are largely based on the chemistry of large (a few grams) of bulk heterogeneous meteorites, where components formed in very different environments are measured together. Over recent years, our group has been at the forefront of extending the boundaries of cosmochemistry, using new tools to unravel early solar system processes. We have developed a unique methodology that allows us to determine the chemistry of some of the earliest solids formed in the inner solar system. We have proven the effectiveness of our technique, and our preliminary data already challenge existing models. We are world leaders in this type of work, and are now able to define the compositional makeup for individual components within these highly heterogeneous objects, for the first time. Knowing the chemistry of chondritic components allows us to define the thermal environment of our own proto-planetary disk - its heterogeniety, as well as processes such as volatile depletion (the mechanism by which we arrived at rocky inner planets, as opposed to objects like Uranus), and chondrule formation (the mechanism by which some of the first solids were formed). Understanding the chemistry and thermal environment of our own proto-planetary disk is vital in understanding its formation and evolution, and more generally, how disks and planets around other stars may have formed. Our proposal is for two years funding for a postdoctoral research scientist - an individual who is already a specialist in the relevant techniques - in addition to funding to cover instrumentation costs and consumables. The research is specifically relevant to the theme of 'How do planetary systems evolve', and 'How were the chemical elements created', outlined in the STFC Delivery Plan 2008/9-2011/12.