Organic matter responses to radiation under lunar conditions

Large bodies, such as the Moon, which have remained relatively unaltered for long periods of time have the potential to preserve a record of organic chemical processes from early in the history of the solar system. A record of volatiles and impactors may be preserved in buried lunar regolith layers that have been capped by protective lava flows. Of particular interest is the possible preservation of prebiotic organic materials delivered by ejected fragments of other bodies, including those originating from the surface of the early Earth. Lava flow layers would shield the underlying regolith and any carbon-bearing materials within them from most of the effects of space weathering, but the encapsulated organic materials would still be subject to irradiation before they were buried by regolith formation and capped with lava. We have performed a study to simulate the effects of solar radiation on a variety of organic materials mixed with lunar and meteorite analogue substrates. A fluence of ~3 x 1013 protons cm-2 at 4-13 MeV, intended to be representative of solar energetic particles, has little detectable effect on low molecular weight (≤C30) hydrocarbon structures that can be used to indicate biological activity (biomarkers) or the high molecular weight hydrocarbon polymer poly(styrene-co-divinylbenzene), and has little apparent effect on a selection of amino acids (≤C9). Inevitably, more lengthy durations of exposure to solar energetic particles may have more deleterious effects and rapid burial and encapsulation will always be more favourable to organic preservation. Our data indicate that biomarker compounds that may be used to infer biological activity on their parent planet can be relatively resistant to the effects of radiation, and may have a high preservation potential in paleoregolith layers on the Moon

Petrography and bulk composition of Miller Range 05035: a new lunar VLT gabbro

Miller Range (MIL) 05035 is a crystalline lunar mare gabbroic meteorite collected in Antarctica in 2005 [1]. It is an important new sample in the lunar meteorite (LM) collection as it is only one of ~8 to be classified as basaltic in nature. MIL 05035 is coarsely grained with large pyroxene grains ( 8mm) subophitically enclosing plagioclase grains ( 6mm), and accessory ilmenite, spinel, silica and sulphide phases

The Intentional Fieldwork Education Model: Guiding Fieldwork Educators Toward Intentionality and Competency to Enhance Student Learning

Fieldwork education is an essential component of occupational therapy education. The level of competency and preparedness of fieldwork educators may vary substantially and may significantly impact student learning outcomes. The availability of an evidence-based comprehensive fieldwork model to guide the fieldwork educator, clarify issues related to teaching-learning, and provide insightful solutions to issues the educator may encounter, is warranted but is not currently available. The intentional fieldwork education model, introduced in this article, was developed to provide a framework to enhance fieldwork educator competency, self-efficacy, and student learning outcomes. In addition, the model emphasizes the significance of intentionality in the fieldwork education process and provides educators with evidence and information to promote the process of intentional education throughout the learning continuum. The article will describe the tenets of the intentional fieldwork education model, research results supporting the need and perceived utility of the model, and promote its application among clinical and academic educators

The Intentional Fieldwork Educator: Applying the Intentional Fieldwork Education Model (IFWEM)

This presentation introduces the Intentional Fieldwork Education Model (IFWEM). This model emphasizes intentional teaching and the application of the occupational therapy lens in the clinical education process. The IFWEM incorporates the frameworks of Transformational Learning Theory (Canton & Taylor, 2012), Experiential Learning Theory (Lisko & O’dell, 2010), and Pedandragogy (Samaroo, Cooper & Green, 2013) to improve the effectiveness of teaching-learning during the fieldwork experience through intentional engagement. The creation of intentional learning experiences, student assimilation into the clinic culture, and modification and pacing of learning during the clinical education process are discussed. In addition, the impact of collaborative relationships, effective communication and feedback, teaching styles, and the integration of learning styles into the fieldwork experience are explored. Following an in-depth presentation of the concepts of the model, a series of applicable vignettes are presented

Creating Opportunities for OT-OTA Student Learning Through Community Collaborations

Providing occupational therapy (OT) and occupational therapy assistant (OTA) students with collaborative educational experiences can foster an understanding of role delineation and lay the foundation for positive relationships in future work environments. Offering these experiences during the didactic portion of the curriculum can provide a deeper understanding of the OT-OTA relationship and encourage greater intraprofessional collaboration in fieldwork settings and as practitioners. This project was an intraprofessional educational experience between students enrolled in a graduate OT master’s degree program and students enrolled in an OTA program. In the first phase students met and socialized with each other, discussed role delineation, completed case studies, and planned group interventions. In the second phase, students led groups at a community based work activity center for adults with intellectual disabilities and spent more time in intraprofessional collaboration as they debriefed and discussed their experience. To assess student understanding and perceptions of the learning experience, a survey was administered to all student participants for the past two years, 2016 and 2017. The majority of the 78 respondents agreed or strongly agreed that the preparatory meeting and implementation of groups increased understanding of the OT-OTA role and role delineation; the learning experience promoted a beginning working relationship between the OT-OTA; the learning experience was effective in promoting the application of learned skills/information; and they would recommend this learning experience for future OT-OTA students

An analysis of Apollo lunar soil samples 12070,889, 12030,187 and 12070,891: basaltic diversity at the Apollo 12 landing site and implications for classification of small-sized lunar samples.

Lunar mare basalts provide insights into the compositional diversity of the Moon’s interior. Basalt fragments from the lunar regolith can potentially sample lava flows from regions of the Moon not previously visited, thus, increasing our understanding of lunar geological evolution. As part of a study of basaltic diversity at the Apollo 12 landing site, detailed petrological and geochemical data are provided here for 13 basaltic chips. In addition to bulk chemistry, we have analysed the major, minor and trace element chemistry of mineral phases which highlight differences between basalt groups. Where samples contain olivine, the equilibrium parent melt magnesium number (Mg#; atomic Mg/(Mg + Fe)) can be calculated to estimate parent melt composition. Ilmenite and plagioclase chemistry can also determine differences between basalt groups. We conclude that samples of ~1-2 mm in size can be categorized provided that appropriate mineral phases (olivine, plagioclase and ilmenite) are present. Where samples are fine-grained (grain size <0.3 mm), a “paired samples t-test” can provide a statistical comparison between a particular sample and known lunar basalts. Of the fragments analysed here, three are found to belong to each of the previously identified olivine and ilmenite basalt suites, four to the pigeonite basalt suite, one is an olivine cumulate, and two could not be categorized because of their coarse grain sizes and lack of appropriate mineral phases. Our approach introduces methods that can be used to investigate small sample sizes (i.e., fines) from future sample return missions to investigate lava flow diversity and petrological significance

Searching for nonlocal lithologies in the Apollo 12 regolith: a geochemical and petrological study of basaltic coarse fines from the Apollo lunar soil sample 12023,155

New data from a petrological and geochemical examination of 12 coarse basaltic fines from the Apollo 12 soil sample 12023,155 provide evidence of additional geochemical diversity at the landing site. In addition to the bulk chemical composition, major, minor, and trace element analyses of mineral phases are employed to ascertain how these samples relate to the Apollo 12 lithological basalt groups, thereby overcoming the problems of representativeness of small samples. All of the samples studied are low-Ti basalts (0.9–5.7 wt% TiO2), and many fall into the established olivine, pigeonite, and ilmenite classification of Apollo 12 basaltic suites. There are five exceptions: sample 12023,155_1A is mineralogically and compositionally distinct from other Apollo 12 basalt types, with low pigeonite REE concentrations and low Ni (41–55 ppm) and Mn (2400–2556 ppm) concentrations in olivine. Sample 12023,155_11A is also unique, with Fe-rich mineral compositions and low bulk Mg# (=100 × atomic Mg/[Mg+Fe]) of 21.6. Sample 12023,155_7A has different plagioclase chemistry and crystallization trends as well as a wider range of olivine Mg# (34–55) compared with other Apollo 12 basalts, and shows greater similarities to Apollo 14 high-Al basalts. Two other samples (12023,155_4A, and _5A) are similar to the Apollo 12 feldspathic basalt 12038, providing additional evidence that feldspathic basalts represent a lava flow proximal to the Apollo 12 site rather than material introduced by impacts. We suggest that at least one parent magma, and possibly as many as four separate parent magmas, are required in addition to the previously identified olivine, pigeonite, and ilmenite basaltic suites to account for the observed chemical diversity of basalts found in this study

Full moon exploration

The Moon is a promising science target, made a priority in recent space exploration plans. So far, polar landing sites have been preferred, but many promising scientific objectives lie elsewhere. Here we summarize the potential value of one such scientific target, northern Oceanus Procellarum, which includes basalts of a wide range of ages. Studying these would allow refinement of the lunar stratigraphy and chronology, and a better understanding of lunar mantle evolution. We consider how exploration of such areas might be achieved in the context of lunar exploration plans

Lunar basalt chronology, mantle differentiation and implications for determining the age of the Moon

Despite more than 40 years of studying Apollo samples, the age and early evolution of the Moon remain contentious. Following the formation of the Moon in the aftermath of a giant impact, the resulting Lunar Magma Ocean (LMO) is predicted to have generated major geochemically distinct silicate reservoirs, including the sources of lunar basalts. Samples of these basalts, therefore, provide a unique opportunity to characterize these reservoirs. However, the precise timing and extent of geochemical fractionation is poorly constrained, not least due to the difficulty in determining accurate ages and initial Pb isotopic compositions of lunar basalts. Application of an in situ ion microprobe approach to Pb isotope analysis has allowed us to obtain precise crystallization ages from six lunar basalts, typically with an uncertainty of about ±10Ma, as well as constrain their initial Pb-isotopic compositions. This has enabled construction of a two-stage model for the Pb-isotopic evolution of lunar silicate reservoirs, which necessitates the prolonged existence of high-μ reservoirs in order to explain the very radiogenic compositions of the samples. Further, once firm constraints on U and Pb partitioning behaviour are established, this model has the potential to help distinguish between conflicting estimates for the age of the Moon. Nonetheless, we are able to constrain the timing of a lunar mantle reservoir differentiation event at 4376±18Ma, which is consistent with that derived from the Sm–Nd and Lu–Hf isotopic systems, and is interpreted as an average estimate of the time at which the high-μ urKREEP reservoir was established and the Ferroan Anorthosite (FAN) suite was formed