Periodic Reporting for period 1 - XeMoon (Sources and sinks for excess Xe and Ar on the Moon)
Reporting period: 2018-05-01 to 2020-04-30
The lunar exosphere balances sources - volcanic outgassing and, impacts (delivery degassing) - and sinks – loss to space, trapping into the regolith. This project aims to track exospheric Xe and Ar through sources and sinks to understand the Moon’s history, and develop a model to account for the data. This is important to society because the Moon preserves a record of the Solar System's early history that the Earth has lost; this is the time when life was beginning on Earth and the surfaces of Mercury and Mars were being shaped.
A number of factors led to a delay in the acquisition of xenon isotopic data. It has been agreed that these analyses will be completed once facilities reopen following COVID19 pandemic closure. Accurate chronology of events on the lunar surface to be used in exospheric models is already making us revise our understanding of the early history of the Earth and the inner Solar System, with far-reaching implications. Details are subject to embargo, but the lunar record gives insight into the bombardment history of the early Earth and, thus, the timing of the emergence of life on our planet and the environment it experienced. Since the Moon is used as the benchmark for relating crater densities to absolute ages across the inner Solar System, this leads to a re-evaluation of the first billion years of Mercury, Mars, asteroid belt, etc. This work also provides new insights into volcanic processes shaping the Moon’s crust and the evolution of its mantle, extending the time period over which volcanism is known to have shaped the Maria Imbrium and Serenitatis.
A number of factors led to a delay in the acquisition of xenon isotopic data. It has been agreed that these analyses will be completed once facilities reopen following COVID19 pandemic closure. Accurate chronology of events on the lunar surface to be used in exospheric models is already making us revise our understanding of the early history of the Earth and the inner Solar System, with far-reaching implications. Details are subject to embargo, but the lunar record gives insight into the bombardment history of the early Earth and, thus, the timing of the emergence of life on our planet and the environment it experienced. Since the Moon is used as the benchmark for relating crater densities to absolute ages across the inner Solar System, this leads to a re-evaluation of the first billion years of Mercury, Mars, asteroid belt, etc. This work also provides new insights into volcanic processes shaping the Moon’s crust and the evolution of its mantle, extending the time period over which volcanism is known to have shaped the Maria Imbrium and Serenitatis.
Apollo samples loaned by NASA have been fully characterized. A protocol was develop that enabled complete characterization (Fig 1) of the material using an array of analytical techniques. Age data is vital for better understanding of impact flux onto the Earth-Moon system to improve an estimation of Xe and Ar sources delivered by impacting material and released during volcanism (Fig.2) and that lost following heating and melting of the surface. Ar-isotopic analyses have been made for age determination and evaluation of sources and sinks, complementary U/Pb dates have been acquired. Xe-isotope analyses suggest that volcanic glasses and basaltic regolith fragments had complex burial histories. Several new collaborations have also been initiated across Europe and with colleagues in China (under the auspices of the ESA-CNSA Research Team).
The major results of the project are:
1 First Xe data from individual lunar volcanic glass beads allowing constraining of their burial history and exposure and the extent of xenon preservation from their source magma.
2 Extending the duration of volcanic activity in Mare Imbrium and Mare Serenitatis.
3 Re-evaluating the bombardment history of the inner Solar System based on improved selection of samples constraining absolute ages of specified impact events.
A manuscript for (1) is in preparation. (2) was presented at international conferences including the EPSC-Berlin (2018), the MetSoc-Sapporo (2019) and the 34th NGW-Oslo (2020). For (3) a paper is currently submitted to Nature and further publications are in preparation; it was presented at the ELS-Toulouse (2018), the EGU-Vienna (2018), AGU-San Francisco, 2018), and the 34th NGW-Oslo (2020).
The major results of the project are:
1 First Xe data from individual lunar volcanic glass beads allowing constraining of their burial history and exposure and the extent of xenon preservation from their source magma.
2 Extending the duration of volcanic activity in Mare Imbrium and Mare Serenitatis.
3 Re-evaluating the bombardment history of the inner Solar System based on improved selection of samples constraining absolute ages of specified impact events.
A manuscript for (1) is in preparation. (2) was presented at international conferences including the EPSC-Berlin (2018), the MetSoc-Sapporo (2019) and the 34th NGW-Oslo (2020). For (3) a paper is currently submitted to Nature and further publications are in preparation; it was presented at the ELS-Toulouse (2018), the EGU-Vienna (2018), AGU-San Francisco, 2018), and the 34th NGW-Oslo (2020).
A new protocol was developed to mount valuable and rare samples allocated in small amounts preventing loss of Xe and demounting.
Combining multiple analytical techniques allowed (1) distinguishing volcanic from impact glasses, (2) the observation of bubbles/vesicles in volcanic glasses suggesting loss of gas from the melt (3) evaluation of the volume percent of the different phases in lunar basalts enabling proper interpretation of age data (4) the identification of U-bearing mineral phases for in-situ U/Pb age determination. I have shown that diverse datasets can be acquired from a mere ~50mg (2-4 mm diameter) of single-lithology lunar regolith fragments, yielding information regarding the sample’s geologic history, including events that may have affected its original composition and texture, and also paths on the lunar surface as a particle of the lunar regolith. This is vital for understanding subsequent noble gas analysis.
My work on the chronology of the lunar surface has wide implications for our understanding of the origin of life and the nature of the environment experienced by early organisms.
I instigated a cross-European network for inter-calibration of age dating labs and to source a new supply of the Hb3gr standard for the widely used 40Ar/39Ar technique widely used across terrestrial geoscience. Around 500 new vials have been produced, they are stored at the GeoForschung Zentrum (GFZ) in Potsdam, Germany and available to the community.
I have helped expand European capacity to participate in planetary science by collaborating with the Ar-laboratory at the Technical University of Freiberg, Germany to develop their capabilities in analysis of extraterrestrial samples to match the terrestrial expertise they have developed since establishment early in the 21st century.
My project illustrates the immense scientific resource preserved on the lunar surface. I passionately believe that this is part of humanity’s collective inheritance, and am concerned that the ethical aspects of using the resources in the lunar surface to support exploration and, potentially, industry (in situ resource utilization - ISRU) are insufficiently considered. During the project, I was able to organize a workshop immediately after the European Lunar Symposium in 2019 at the University of Manchester: The Moon as a ‘contact zone’ to other worlds: an interdisciplinary workshop. This brought together scientists, social scientists and interested members of the general public to discuss means to avoid the repeated colonialist mind-set in which many are planning ventures to other worlds. As a consequence, I was invited to present “The Moon is NOT ours” at the British Science Festival in Coventry in September 2019. I have taken part in a wide range of activities to disseminate information about my project and lunar science in general across the UK, Germany, Portugal, China and Vietnam.
Combining multiple analytical techniques allowed (1) distinguishing volcanic from impact glasses, (2) the observation of bubbles/vesicles in volcanic glasses suggesting loss of gas from the melt (3) evaluation of the volume percent of the different phases in lunar basalts enabling proper interpretation of age data (4) the identification of U-bearing mineral phases for in-situ U/Pb age determination. I have shown that diverse datasets can be acquired from a mere ~50mg (2-4 mm diameter) of single-lithology lunar regolith fragments, yielding information regarding the sample’s geologic history, including events that may have affected its original composition and texture, and also paths on the lunar surface as a particle of the lunar regolith. This is vital for understanding subsequent noble gas analysis.
My work on the chronology of the lunar surface has wide implications for our understanding of the origin of life and the nature of the environment experienced by early organisms.
I instigated a cross-European network for inter-calibration of age dating labs and to source a new supply of the Hb3gr standard for the widely used 40Ar/39Ar technique widely used across terrestrial geoscience. Around 500 new vials have been produced, they are stored at the GeoForschung Zentrum (GFZ) in Potsdam, Germany and available to the community.
I have helped expand European capacity to participate in planetary science by collaborating with the Ar-laboratory at the Technical University of Freiberg, Germany to develop their capabilities in analysis of extraterrestrial samples to match the terrestrial expertise they have developed since establishment early in the 21st century.
My project illustrates the immense scientific resource preserved on the lunar surface. I passionately believe that this is part of humanity’s collective inheritance, and am concerned that the ethical aspects of using the resources in the lunar surface to support exploration and, potentially, industry (in situ resource utilization - ISRU) are insufficiently considered. During the project, I was able to organize a workshop immediately after the European Lunar Symposium in 2019 at the University of Manchester: The Moon as a ‘contact zone’ to other worlds: an interdisciplinary workshop. This brought together scientists, social scientists and interested members of the general public to discuss means to avoid the repeated colonialist mind-set in which many are planning ventures to other worlds. As a consequence, I was invited to present “The Moon is NOT ours” at the British Science Festival in Coventry in September 2019. I have taken part in a wide range of activities to disseminate information about my project and lunar science in general across the UK, Germany, Portugal, China and Vietnam.