Exploring the lunar regolith at the microscale
PhD 3 years Manchester, UK
Uploaded 16 Apr 2018
This project will use a range of non-destructive state of the art analytical techniques to characterise the physical and chemical properties of small (<1 mm) lunar soil components from a range of geological settings. Our integrated analytical approach will investigate the range of processes that control soil formation and recycling on the Moon and address key lunar science and exploration goals (NRC, 2007; Joy et al., 2011, 2012).
Lunar science project details: The Moon is covered with a soil-like layer called a regolith (McKay et al., 1991; Spray, 2016). This boundary layer preserves a record both of the Moon’s crust formation and modification history, and of its evolution driven by impacting asteroids and comets. Regolith is made from rock and mineral fragments, and also unique sub-mm sized glassy ‘agglutinate’ constructs produced by a combination of micrometeorite impacts and solar wind and cosmic ray irradiation. The number of agglutinates present in a lunar soil typically increases with sample surface exposure (a physio-chemical phenomena termed as “maturity”). Thus, agglutinates are a uniquely important indicator of regolith production and recycling, and are a key to understanding space weathering processes (McKay and Basu, 1983). At a larger scale, knowledge of the processes that create and modify the lunar regolith is crucial to also understanding the compositional and structural attributes of other airless planet and asteroid regoliths. However, the exact formation history of agglutinates and chemical relationship to the lunar parent soil in which they formed is poorly understood (Vance et al., 2016): this topic forms the core of the project.
The student will work with agglutinates extracted from Apollo (US mission) and Luna (Russian samples) soils. We will utilise newly available non-destructive analytical techniques (Kiely et al. 2011; Vonlanthen et al., 2015; Martin et al., 2017) to undertake microscale investigations of individual agglutinates. The project will utilise analytical facilities within the SEES, including e-beam methods (SEM, EMPA) and FTIR spectroscopy and the Manchester X-ray imaging Facility (MXIF) CT facilities at UoM. Applications will also be made for time at the Diamond X-ray synchrotron through UoM access routes.
Planetary exploration activities: A vital component of this PhD is to also to help catalogue the Royal Society’s Luna sample collection. Little research has been undertaken on these samples since the 1980s and the collection now needs to be properly and thoroughly described, photographed and recorded in a database so that the sample can be curated appropriately to enable future research. Technical reports on each of the remaining Luna sample collections will be key outcomes of this project and will have significant long-term benefits for the Royal Society and to the UK cosmochemistry community. The knowledge gained from preparation, analysis and curation of precious small-sized extraterrestrial samples will leverage involvement in planning for future lunar sample-return missions. Back scatter electron images of agglutinates in an ancient Apollo fused soil sample. These constructs are formed of mineral clasts in a vesicular heterogeneous glassy matrix.
Timeline: In all years of the project the student will attend relevant specialist training courses, attend conference to present outcomes, and will interact with our collaborators at the ESA analogue curation facility at the Harwell campus in Oxfordshire.
We are seeking a student with a good degree in geology / planetary science / geochemistry with good knowledge of planetary science and some experience working with analytical instrumentation. Demonstrating that you have undertaken independent research is desired.