The Winchcombe Meteorite: one year on

It was the first UK meteorite fall for 30 years. Here we gather the story of a remarkable community hunt involving pandemic precautions, social media spikes and some very lucky guinea pigs.

Towards a New Architecture of Cosmic Experience

The article unfolds an account of several overlapping fields of inquiry contributing to the early modern experience of the cosmos. Traversing scale, scope, and media, from the first recorded meteorite fall to scholastic debates over the materiality of heaven and the practice of architecture as cosmic analogue, I argue in favour of bringing together a broad range of interdisciplinary source material in order to explore the spatiality of the cosmos and how it was encountered and reproduced as a place or cosmic space or non-place on earth. The accompanying examples gesture towards an open-ended model defined not solely by the built environment as much as by the ephemeral and rhetorical structures framing the cosmos for human consumption.

Russia in Supercritical Situation: Managing Restoration of Life-Support Functions to Overcome the Consequences of a Natural Macro Catastrophe

Supercritical fluid is a state of matter when its temperature and pressure are above the critical point. Supercritical situation is a state of the economy in its cumulative manifestations and mutual influence, whereby the state of key life-support profiles is below the critical point of controllability. Various forecasts are increasingly actualizing the probability of a natural (and man-made) macro-catastrophe (a large meteorite fall, an earthquake of 10–12 points and others, as well as a pandemic similar to COVID–19, but with more severe consequences). As the coronavirus pandemic has shown, modern civilization is becoming ever more vulnerable to such disasters. To overcome the destabilizing trends of a natural (and man-made) macro-catastrophe, it is necessary to adopt proactively a set of measures in Russia that will drastically increase the efficiency of public administration in relation to the list of regulated resource, economic, technical, social and other parameters incorporating mechanisms and procedures of public administration into market mechanisms and the budgeting structure with regard to external and internal factors of the supersystem's vital activities.

The Moroccan experience on Meteoritics and Planetary Science

<p>Morocco is a treasure house of meteorites, most meteorites accessible to scientists and collectors in all over the world are originated from Morocco and surrounding countries. Collection of meteorites is essentially done in hot and cold deserts. Morocco has a large and safe Sahara where many nomads are living. A big community of meteorite hunters is well established. Nomads and hunters are good observers, they learned by practicing how to make the difference between terrestrial and extra-terrestrial rocks that represent an important source of revenue for them. Those meteorites are almost all exported. All classes of meteorites are found in the hot deserts including many rare and important for scientific research ones.</p> <p>Since 2001, our team in the Hassan II University of Casablanca Faculty of Science Ain Chock is working on the promotion of meteorites in Morocco, Arab countries and Africa. Cosmochemistry courses has been introduced to the national curricula. Many PhD thesis has been prepared and defended. Since 2004 meteorite falls in Morocco have been classified and submitted to the Nomenclature Committee of the Meteoritical Society by our team, including the exceptional fifth Martian meteorite fall in Morocco “Tissint”. Many valuable papers have been published on these falls.</p> <p>On 2019, ATTARIK Foundation for Meteoritics and Planetary Science was created by our team and a group of passionate people. The aim of ATTARIK is to support the research of the PhD students on Planetary Sciences and to disseminate sciences through youth in cities and countryside. The Africa Initiative for Planetary and Space Science was launched on 2016 in Cape Town has similar objectives.</p> <p>The Moroccan experience can be a good reference to development of planetary sciences in Africa and the Arab countries.</p>

An investigation of the 27 July 2018 bolide and meteorite fall over Benenitra, southwestern Madagascar

Several dozen stones of an ordinary chondrite meteorite fell in and around the town of Benenitra in southwestern Madagascar during the early evening of 27 July 2018, minutes after a widely observed meteor fireball (bolide) transit and detonation. The event was confirmed by low-frequency infrasound recordings received at ~17h15 UTC (Coordinated Universal Time; 19h15 local time) at the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) infrasound station I33MG near Antananarivo, 542 km northnortheast of Benenitra. An energy release equivalent to 2.038 kt of TNT was calculated from the infrasound signals. Seismograph readings at the SKRH station 77 km north-northwest of Benenitra recorded a twostage signal consistent with the arrivals of an initial air-coupled ground wave at 16h48:08 UTC and a stronger pulse at 16h49:22 UTC linked directly to the atmospheric pressure wave. The infrasound and seismic signal arrival times suggest that the bolide entry and detonation occurred at approximately 18h46 local time (16h46 UTC), entry was from the northwest, and the detonation hypocentre was located within ~20 km of Benenitra. Despite meteorite debris being found among buildings within Benenitra, there was no damage to structures or injuries reported. Eyewitness accounts and photographic records indicate that approximately 75 mostly intact stones were collected; however, the remoteness of the area, the rugged nature of the terrain and sales of fragments to meteorite collectors have limited scientific analysis of the fall and the extent of the strewn field. The total mass of recovered stones is estimated at between 20 kg and 30 kg, with one fragment of 11.2 kg and several of ~1 kg. Petrographic and mineral chemical analyses indicate that the stones belong to the L6 class of ordinary chondrites. Cosmogenic radionuclide analysis confirms that the fall is linked to the bolide event. The name Benenitra has been officially accepted by the Meteoritical Bulletin Database.

A composite luminous and dark flight model allowing strewn field prediction

<p>As of today, instrumentally observed meteorite falls account for only 37 recovered meteorite cases, with derived Solar System orbit, out of 65098 registered meteorite names. To bridge this knowledge gap, a number of fireball networks have been set up around the globe. These networks regularly obtain thousands of records of well-observed meteor phenomena, some of which may be classified as a likely meteorite fall (Sansom et al. 2019). A successful recovery of a meteorite from the fireball event often requires that the science team can be promptly directed to a well-defined search area. Here we present a neat Monte Carlo model, which comprises adequate representation of the processes occurring during the luminous trajectory coupled together with the dark flight (Moilanen et al. 2021). In particular, the model accounts for fragmentation and every generated fragment may be followed on its individual trajectory. Yet, the algorithm accounts only for the mass constrained by the observed deceleration, so that the model does not overestimate the total mass of the fragments on the ground (and this mass may also be retrieved as zero). We demonstrate application of the model using historical examples of well-documented meteorite falls, which illustrate a good match to the actual strewn field with the recovered meteorites, both, in terms of fragments’ masses and their spatial distribution on the ground. Moreover, during its development, the model has already assisted in several successful meteorite recoveries including Annama, Botswana (asteroid 2018 LA), and Ozerki (Trigo-Rodríguez et al. 2015, Lyytinen and Gritsevich 2016, Maksimova et al. 2020, Jenniskens et al. 2021).</p><p>References</p><p>Jenniskens P. et al. (2021). Asteroid 2018 LA, impact, recovery and origin on Vesta. Submitted to Science.</p><p>Lyytinen E., Gritsevich M. (2016). Implications of the atmospheric density profile in the processing of fireball observations. Planetary and Space Science, 120, 35-42 http://dx.doi.org/10.1016/j.pss.2015.10.012</p><p>Maksimova A.A., Petrova E.V., Chukin A.V., Karabanalov M.S., Felner I., Gritsevich M., Oshtrakh M.I. (2020). Characterization of the matrix and fusion crust of the recent meteorite fall Ozerki L6. Meteoritics and Planetary Science 55(1), 231–244, https://doi.org/10.1111/maps.13423 </p><p>Moilanen J., Gritsevich M., Lyytinen E. (2021). Determination of strewn fields for meteorite falls. Monthly Notices of the Royal Astronomical Society, in revision.</p><p>Sansom E.K., Gritsevich M., Devillepoix H.A.R., Jansen-Sturgeon T., Shober P., Bland P.A., Towner M.C., Cupák M., Howie R.M., Hartig B.A.D. (2019). Determining fireball fates using the α-β criterion. The Astrophysical Journal 885, 115, https://doi.org/10.3847/1538-4357/ab4516</p><p>Trigo-Rodríguez J.M., Lyytinen E., Gritsevich M., Moreno-Ibáñez M., Bottke W.F., Williams I., Lupovka V., Dmitriev V., Kohout T., Grokhovsky V. (2015). Orbit and dynamic origin of the recently recovered Annama’s H5 chondrite. Monthly Notices of the Royal Astronomical Society, 449 (2): 2119-2127, http://dx.doi.org/10.1093/mnras/stv378</p>

Determination of strewn fields for meteorite falls

ABSTRACT When an object enters the atmosphere it may be detected as a meteor. A bright meteor, called a fireball, may be a sign of a meteorite fall. Instrumentally observed meteorite falls provide unique opportunities to recover and analyse unweathered planetary samples supplemented with the knowledge on the Solar system orbit they had. To recover a meteorite from a fireball event, it is essential that recovery teams can be directed to a well-defined search area. Until recently, simulations showing the realistic mapping of a strewn field were difficult, in particular due to the large number of unknowns not directly retrieved from the fireball observations. These unknowns include the number of fragments and their aerodynamic properties, for which the masses of the fragments need to be assumed in a traditional approach. Here, we describe a new Monte Carlo model, which has already successfully assisted in several meteorite recoveries. The model is the first of its kind as it provides an adequate representation of the processes occurring during the luminous trajectory coupled together with the dark flight. In particular, the model comprises a novel approach to fragmentation modelling that leads to a realistic fragment mass distribution on the ground. We present strewn field simulations for the well-documented Košice and Neuschwanstein meteorite falls, which demonstrate good matches to the observations. We foresee that our model can be used to revise the flux of extra-terrestrial matter onto the Earth, as it provides a possibility of estimating the terminal mass of meteorite fragments reaching the ground.