Abstract The school associated with this volume was inspired by the recent advances in our understanding of the nature and evolution of our Solar System that have come from the missions to study and sample asteroids and comets, and the very successful Mars orbiters and landers. At the same time our horizons have expanded greatly with the discovery of extrasolar protoplanetary disks, planets and planetary systems by space telescopes. The continued success of such telescopic and robotic exploration requires a supply of highly skilled people and so one of the goals of the Glasgow school was to help build a community of early-career planetary scientists and space engineers.

Abstract Chondritic meteorites are fragments of ‘cosmic sandstone’ from space. They are chemically similar to the Sun and so have been regarded historically as samples from the first crop of planetesimals that accreted in the solar protoplanetary disk. Their component ‘sand grains’ include rare objects known as CAIs (calcium aluminium-rich inclusions) and abundant ones called chondrules; both cooled down from magmatic temperatures. CAIs are the oldest dated solar system solids at 4567 to 4568 Myr old. They probably condensed in a hot vaporized region of the disk, and they incorporated radioactive 26Al. Most chondrules, in contrast, are frozen droplets of ultramafic magma. They also incorporated radioactive 26Al but often ~80% less, relative to 27Al, than in CAIs, so probably formed ~2 Myr after CAIs. Chondrules are widely regarded as having formed when clumps of dust in the disk became ‘flash-melted’. However, by 2 Myr after CAIs, to judge from 182W deficit dating of iron meteorites, much of the dust in the disk had already evolved into a host of substantially molten planetesimals intensely heated by the decay of 26Al. Planet-forming mergers between those bodies would have led to ‘splashing’ with ejecta plumes of molten droplets being recycled to the disk. Such droplets account plausibly for most chondrules, with chondrites being construction debris from planet building rather than primary raw material. Their solar chemistry probably reflects late remixing of processed planetary materials. They did not melt because they accreted after 26Al had largely decayed.

Abstract Comets and the asteroidal parents of chondritic meteorites formed from primitive materials in the early Solar System, including water and organics, and have remained undifferentiated since their accretion. Thus, dust particles and meteorites derived from these bodies that are available for study in the laboratory contain constituents of the solar nebula, although we must always be mindful that post-accretionary processing within parent bodies may have modified the original components, including organics, and synthesized new materials. A review of the organics that have been recovered in the most primitive of the chondritic meteorites is presented here. Similar material that occurs in interplanetary dust particles and micrometeorites, and in cometary grains returned to Earth by the Stardust mission, is discussed. A focus of the review is on materials that can be studied by laboratory techniques including gas source mass spectrometry, secondary ion mass spectrometry and other organic chemistry methods.

Abstract Asteroids and comets comprise a diverse range of undifferentiated bodies that are currently of much interest in terms of space exploration. The meteorites called chondrites provide us with a valuable source of information on the origin and evolution of their parent bodies. From careful study of these meteorites the primordial mineralogy can be inferred by keeping in mind that these bodies suffered thermal metamorphism and/or aqueous alteration just after their formation. In this context, newly available instruments allow us to extract chemical, isotopic, and mineralogical information on the components of primitive meteorites. This is essential to better understand the physico-chemical processes operating during the different evolutionary stages experienced by the parent bodies of chondrites.

Abstract Hypervelocity impacts are a fundamental and quite common process in the Solar System. Extreme pressures, temperatures and stress and strain rates characterize an impact event. These unique transient physical parameters result in unique geological and mineralogical phenomena that include the formation of (macroscopic) shatter cones, and shock effects at the scale of minerals. Adiabatic pressure release and post-shock heating generate decomposition, melting and vaporization of rocks. In this chapter these shock and post-shock effects are discussed in terms of formation processes and characteristic features. A case study on the Lake Bosumtwi crater illustrates geochemical aspects of impact melt formation. Key facts about the high-pressure mineral phases in strongly shocked meteorites are discussed. Finally, key results of a unique series of meso-scale cratering experiments ('The MEMIN project') provide details of the role of target porosity in cratering efficiency and the ejection process.

Abstract The Earth’s Moon is the largest natural satellite in the inner Solar System. The Moon is also witness to more than 4.5 Ga of Solar System history and is the only planetary body other than the Earth for which we have collected samples from known locations. Moreover, the lunar surface preserves a record of the cratering rate and the evolution of solar and galactic cosmic radiations throughout the history of the Solar System. Understanding the Moon is essential to understanding both the Earth and our Solar System. Consequently, the Moon was the prime target in Solar System exploration programs, before the pursuit of more distant targets such as Mars and beyond. Our knowledge about the Moon is based on telescopic observations from the Earth, observations by spacecraft from the lunar orbit, measurements on the lunar surface by manned and unmanned lander missions and the analyses of lunar samples in terrestrial laboratories. The knowledge gained from the Apollo and Luna programs of the 1960s and subsequent lunar missions, carried out over the last four decades, continues to demonstrate the value of the Moon in the understanding of our Solar System and the fundamental processes that drive planetary formation and evolution. Because of its restricted geological activity and relatively simple composition compared with the Earth, the Moon provides insights into elementary planetary processes. In comparison to the Earth, the Moon is depleted in both volatile elements, and iron and other siderophile elements. Recently, however, the presence of H2O and OH has been confirmed on the lunar surface as well as in lunar samples. While it has long been suspected that water-ice might be preserved in cold traps at the lunar poles, recent results indicate the presence of OH and H2O outside of these regions. This new discovery makes the Moon an extremely interesting target once again, both scientifically and as a potential resource. Although new data have helped to address some of our questions about the Earth-Moon system, major new questions have emerged and many existing ones remain unanswered.

Abstract Holding up the right hand side of the periodic table, the noble gases reside in a seemingly inert paradise of full-electron-shell-utopia. Not to be fooled by their outwardly disinterested, yet colourful misdemeanour, they provide a wealth of information about the Solar System and its evolution. In this chapter, the noble gases are introduced and their uses in the planetary sciences summarized.

Abstract Primitive meteorites contain a wide range of materials and components. Some are rare and tiny, e.g. presolar grains, others consist of various types of inclusions, and components such as chondrules and matrix with distinct mineralogical, chemical and/or isotopic characteristics. Isotope analyses of meteorites and their components have become a powerful tool in the interpretation and assessment of the origin and formation processes of primitive meteorites. Advancements in analytical instrumentations are driving the gathering of more precise and detailed isotopic data. There is widespread evidence for isotopic variations of different origins in stable isotopes. Well known and most pronounced, for example, are variations in oxygen isotopes, which are probably due to physicochemical processes in the protoplanetary disk. In addition, a number of stellar nucleosynthetic effects have been shown for neutron-rich isotopes carried either in tiny phases or determined in whole-rock samples. These findings have led to the recognition that the inner Solar System was isotopically less homogeneous than previously thought. Radiogenic chronometers, especially short-lived decay systems such as 26 Al- 26 Mg and 53 Mn- 53 Cr, allow us to constrain the timing of processes related to the formation of primitive meteorites and their components

Abstract Impacts from space leave dramatic craters on planetary surfaces. Alterations also occur at the microscopic scale in the rocks of the crater itself due to the extreme shock pressures and elevated temperatures associated with these high-speed impact events. This chapter discusses these metamorphic impact features and explains how they arise. The chapter begins with some of the theoretical background to shock physics and why high-speed impacts (which lead to shocks) are commonplace in the Solar System. It then describes laboratory methods of reproducing shock events before describing the consequences of shocks on rock samples and how these can be used to subsequently gauge the peak shock pressure to which a sample was subjected.

Abstract The Earth accretes some 40,000 tonnes of extraterrestrial material each year. Most of this is interplanetary dust produced by collisions and evaporation of rocky and icy bodies in the Solar System. A fraction of this dust survives hypervelocity impact with the Earth’s upper atmosphere and is collected at the Earth’s surface in the form of microscopic particles (<2mm) called micrometeorites. Significant quantities of micrometeorites are recovered mainly from deep-sea sediments, and snow, ice and loose sediments in polar areas. Micrometeorites provide samples of a variety of dust-producing bodies in the Solar System for laboratory analysis, most notably primitive asteroids and comets which allow exploration of the first stages in the evolution of the protoplanetary disk. Furthermore, the systematic study of unbiased and time-constrained micrometeorite collections allows investigation of the cycles of extraterrestrial input to the global geochemical budget of planet Earth, including its bearing on the emergence of life. Lastly, knowledge of the physical and compositional properties of micrometeorites provides constraints for modelling the source regions and dynamic evolution of the cosmic-dust complex in the near-Earth space, as well as for assessing the potential hazard of dust in the vicinity of the Earth to space activities. This work provides basic information on micrometeoroid production in space and delivery to Earth, atmospheric entry and micrometeorite collections. It gives an overview of current knowledge of the diversity of micrometeorites in terms of their nature and origin, highlighting recent advances in the identification of new types and in the quantification of the flux of extraterrestrial matter to Earth.

Abstract Despite the abundant evidence that rock-encrusting lichens can weather their substrates, it is currently unclear whether rates of lichen-mediated weathering are faster or slower than rates of abiotic weathering of otherwise identical rock surfaces (i.e. are lichens biodestructive or bioprotective?). This question is of considerable academic and commercial importance. Lichens weather rocks by a combination of biophysical and biochemical mechanisms. Fungal hyphae can penetrate into rocks at ≤~0.1 mm y ;1 and sandstones and limestones are especially vulnerable. Biophysical weathering leads to the fragmentation of minerals, exposing grain interiors. These fresh surfaces may be attacked by a variety of compounds including extracellular polysaccharides, lichen acids and oxalic acid. Evidence for the effectiveness of these biochemical agents includes etched and leached mineral grains and reaction products such as oxalate salts, clay minerals and Fe-hydroxides. Few studies have quantified rates of lichen-mediated weathering and fewer still have compared these data with the weathering rate of unencrusted rock surfaces. The conclusion of this work is that lichens enhance the weathering rate of rock surfaces relative to identical but abiotic substrates. As weathered mineral grains and weathering products are bound within the lichen, these materials will not be eroded until the lichen dies after ~10 1 —10 3 y. Thus, despite being active agents of weathering, lichens should stabilize and protect rock surfaces over the short term. Studies of dated surfaces of a variety of rock types colonized by diverse lichen populations are essential before the impact of lichen colonization on rates of rock weathering can be accurately quantified and predicted.