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The inner solar system's biggest and most recent known collision was the Moon-forming giant impact between a large protoplanet and proto-Earth. Not only did it create a disk near Earth that formed the Moon, it also ejected several percent of an Earth mass out of the Earth-Moon system. Here, we argue that numerous kilometer-sized ejecta fragments from that event struck main-belt asteroids at velocities exceeding 10 kilometers per second, enough to heat and degas target rock. Such impacts produce ∼1000 times more highly heated material by volume than do typical main belt collisions at ∼5 kilometers per second. By modeling their temporal evolution, and fitting the results to ancient impact heating signatures in stony meteorites, we infer that the Moon formed ∼4.47 billion years ago, which is in agreement with previous estimates.

Lunar meteorites represent a more random sampling of lunar material than the Apollo or Luna collections and, as such, lunar meteorite impact melt ages are the most important data in nearly 30 years with which to reexamine the lunar cataclysm hypothesis. Within the lunar meteorite breccias MAC 88105, QUE 93069, DaG 262, and DaG 400, seven to nine different impact events are represented with40Ar-39Ar ages between 2.76 and 3.92 billion years ago (Ga). The lack of impact melt older than 3.92 Ga supports the concept of a short, intense period of bombardment in the Earth-moon system at ∼3.9 Ga. This was an anomalous spike of impact activity on the otherwise declining impact-frequency curve.

The SNC (Shergotty-Nakhla-Chassigny) meteorites have recorded interactions between martian crustal fluids and the parent igneous rocks. The resultant secondary minerals -- which comprise up to 1 vol.% of the meteorites -- provide information about the timing and nature of hydrous activity and atmospheric processes on Mars. We suggest that the most plausible models for secondary mineral formation involve the evaporation of low temperature (25 - 150 C) brines. This is consistent with the simple mineralogy of these assemblages -- Fe-Mg-Ca carbonates, anhydrite, gypsum, halite, clays -- and the chemical fractionation of Ca-to Mg-rich carbonate in ALH84001 \"rosettes\". Longer-lived, and higher temperature, hydrothermal systems would have caused more silicate alteration than is seen and probably more complex mineral assemblages. Experimental and phase equilibria data on carbonate compositions similar to those present in the SNCs imply low temperatures of formation with cooling taking place over a short period of time (e.g. days). The ALH84001 carbonate also probably shows the effects of partial vapourisation and dehydration related to an impact event post-dating the initial precipitation. This shock event may have led to the formation of sulphide and some magnetite in the Fe-rich outer parts of the rosettes. Radiometric dating (K-Ar, Rb-Sr) of the secondary mineral assemblages in one of the nakhlites (Lafayette) suggests that they formed between 0 and 670 Myr, and certainly long after the crystallisation of the host igneous rocks. Crystallisation of ALH84001 carbonate took place 0.5 Gyr after the parent rock. These age ranges and the other research on these assemblages suggest that environmental conditions conducive to near-surface liquid water have been present on Mars periodically over the last 1 Gyr. This fluid activity cannot have been continuous over geological time because in that case much more silicate alteration would have taken place in the meteorite parent rocks and the soluble salts would probably not have been preserved. The secondary minerals could have been precipitated from brines with seawater-like composition, high bicarbonate contents and a weakly acidic nature. The co-existence of siderite (Fe-carbonate) and clays in the nakhlites suggests that the pCO sub(2) level in equilibrium with the parent brine may have been 50 mbar or more. The brines could have originated as flood waters which percolated through the top few hundred meters of the crust, releasing cations from the surrounding parent rocks. The high sulphur and chlorine concentrations of the martian soil have most likely resulted from aeolian redistribution of such aqueously-deposited salts and from reaction of the martian surface with volcanic acid volatiles. The volume of carbonates in meteorites provides a minimum crustal abundance and is equivalent to 50-250 mbar of CO sub(2) being trapped in the uppermost 200-1000 m of the martian crust. Large fractionations in d super(18)O between igneous silicate in the meteorites and the secondary minerals (,30ppt) require formation of the latter below temperatures at which silicate-carbonate equilibration could have taken place (400C) and have been taken to suggest low temperatures (e.g. ,150C) of precipitation from a hydrous fluid.

This study examines inter- and intrapersonal problems associated with being overweight among one thousand one hundred sixty-four 6- to 7-year-olds (49% boys) in 29 rural schools. Socioemotional data include child self-reports, peer sociometrics, and teacher reports. Results support the hypothesis that children with weight problems struggle socially and emotionally, and extend current understanding of child obesity by demonstrating that problems appear early, are evident in a community sample, can be identified using standard sociometric methods, and are worse among children with severe obesity. Sociometric status difference between levels of obesity were also found. Although obese children were neglected by peers, severely obese children were rejected.

ObjectivesMany researchers conduct a process evaluation alongside an effectiveness trial of a public health intervention to better understand mechanisms behind observed effects. Yet, there is no standardised, scientifically accepted guideline for reporting such process evaluations, which impedes interpretation and comparison of study results. The aim of this project was to develop a consensus-based and expert-based guideline for reporting process evaluations of public health interventions conducted alongside an effectiveness trial.Design and settingWe conducted an e-Delphi study with a large panel of international experts.ParticipantsBased on purposive sampling, we invited 137 international experts that had been involved in the design of process evaluations, researchers who published high-profile process evaluations or frameworks, editors of journals that publish process evaluations, and authors of other reporting guidelines.ResultsBased on a literature search, a first draft of the reporting guideline included 32 items, which was proposed to panel members during the first round. Of the invited 137 invited international experts, 73 (53%) participated in at least one round of the e-Delphi study. Participants rated the inclusion and comprehensibility of the proposed items on a 5-point Likert scale and provided comments and suggestions for relevance and definitions of the items. Adjustments to the items and descriptions were proposed to the e-Delphi panel until consensus of ≥67% for each individual item was reached. In total, 64 (88% of 73) completed round 2, and 55 (76% of 73) completed round 3. This resulted in 19 items that are included in the consensus-based process evaluation reporting guideline for public health intervention studies (CONPHES) guideline. The items cover a detailed description of the intervention that is evaluated, the implementation strategies applied, and underlying causal pathways, and the role of the delivery and support team. The guideline also requires describing the evaluation framework and how evaluation outcomes were assessed. Lastly, the guideline includes items on providing a detailed description of applied analyses (both quantitative and qualitative) and measures for assuring quality. The guideline is accompanied by an Explanation and Elaboration document, with a more detailed explanation of each item.ConclusionsWe expect that the CONPHES reporting guideline for process evaluations of public health interventions can improve the reporting of process evaluations of interventions aimed at promoting public health. This can potentially facilitate more effective translation of public health research into practice and contribute to improving both individual and population health outcomes.

The world's meteorite collections contain a very rich picture of what the early Solar System would have been made of, however the lack of spatial context with respect to their parent population for these samples is an issue. The asteroid population is equally as rich in surface mineralogies, and mapping these two populations (meteorites and asteroids) together is a major challenge for planetary science. Directly probing asteroids achieves this at a high cost. Observing meteorite falls and calculating their pre-atmospheric orbit on the other hand, is a cheaper way to approach the problem. The Global Fireball Observatory (GFO) collaboration was established in 2017 and brings together multiple institutions (from Australia, USA, Canada, Morocco, Saudi Arabia, the UK, and Argentina) to maximise the area for fireball observation time and therefore meteorite recoveries. The members have a choice to operate independently, but they can also choose to work in a fully collaborative manner with other GFO partners. This efficient approach leverages the experience gained from the Desert Fireball Network (DFN) pathfinder project in Australia. The state-of-the art technology (DFN camera systems and data reduction) and experience of the support teams is shared between all partners, freeing up time for science investigations and meteorite searching. With all networks combined together, the GFO collaboration already covers 0.6% of the Earth's surface for meteorite recovery as of mid-2019, and aims to reach 2% in the early 2020s. We estimate that after 5 years of operation, the GFO will have observed a fireball from virtually every meteorite type. This combined effort will bring new, fresh, extra-terrestrial material to the labs, yielding new insights about the formation of the Solar System.

The inner solar system's biggest and most recent known collision was the Moon-forming giant impact between a large protoplanet and proto-Earth. Not only did it create a disk near Earth that formed the Moon, it also ejected several percent of an Earth mass out of the Earth-Moon system. Here, we argue that numerous kilometer-sized ejecta fragments from that event struck main-belt asteroids at velocities exceeding 10 kilometers per second, enough to heat and degas target rock. Such impacts produce ~1000 times more highly heated material by volume than do typical main belt collisions at ~5 kilometers per second. By modeling their temporal evolution, and fitting the results to ancient impact heating signatures in stony meteorites, we infer that the Moon formed ~4.47 billion years ago, which is in agreement with previous estimates.

The Martian atmosphere has a high X-129/Xe-132 ratio compared to the Martian mantle. As Xe-129 is the daughter product of the extinct nuclide I-129, a means of fractionating iodine from xenon early in Martian history appears necessary to account for the X-129/Xe-132 ratios of its known reservoirs. A model is presented here to account for the Marian xenon data which relies on the very different solubilities of xenon and iodine in water to fractionate them after outgassing. Atmospheric xenon is lost by impact erosion during heavy bombardment, followed by release of Xe-129 produced from I-129 decay in the crust.