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EN
The largest group of fossil meteorites are L type chondrites, found in the Middle Ordovician limestones in Sweden. Until now, 101 specimes were discovered. Probably, they come from collisions in the asteroid belt. They are completely altered, except the chromite grains.
EN
A piece of a meteorite that had crashed through the roof of a cottage house was find in the central Oslo quarter Rodelřkka at the beginning of March 2012. Some days later the second discovery in the melting snow of Ekebergsletta hilltop plateau triggered the hunting for meteorites in almost all sides of Oslo. The pieces of third meteorite broken by cars and spread out by snowplow was discovered on the asphalt road side by Maciek Burski, the member of Polish Meteoritical Society. Later on the missing fragments of the Maciek’s most east find was collected by Meteoritical Section members of Comet and Meteor Workshop (PKiM) with the help of local meteoritical authorities. The total mass of this unobserved fall is 6.22 kg in five pieces spread out in the eight km-long strewnfield with 200 g and 4.65 kg meteorites on the opposite ends. The Meteorite is not classified yet but unofficial information is “breccia H3-4”.
EN
This scientific paper aims to systematize knowledge about the circumstances of meteorite falls in 2018. Eight of them were officially confirmed by The Meteoritical Society: Hamburg (USA), Ablaketka (Kazakhstan), Aba Pan (Nigeria), Mangui (China), Ozerki (Russia), Renchen (Germany), Gueltat Zemmour (Morocco), Komaki (Japan). Seven more have not yet been classified: Central Kalahari (Botswana), Glendale (USA), Benenitra (Madagascar), Bhakkar (Pakistan), Ghadamis (Libya), Elkouran (Morocco) and meteorite fall from the Sahara Desert. It turns out that the most numerous group of meteorite falls in 2018 were L6 chondrites. There were no iron or stony-iron falls. The author collected information from many different sources. He analyzed entries in the MetBull catalog, publications in social media and press reports in order to compare them with official data from previous years. In this way, he tries to prove that although the circumstances of each meteorite fall are different, coherent conclusions can be drawn from them, and these can help meteorite researchers, for example, in verifying eyewitness accounts.
EN
This scientific paper is a summary of the meteorite falls in 2017: Broek in Waterland (Holland), Tres Irmaos (Brazil), Serra Pelada (Brazil) and Kheneg Ljouâd (Morocco). The study also includes a section about unconfirmed falls, such as Puya Medio (Colombia), Mukundpura (India), Crawford Bay (Canada) and Sadiya (India). The vast majority of these specimens is ordinary chondrites of the L and LL groups. Only Serra Pelada meteorite turned out to be eucrite and Mukundpura is suspected to be carbonaceous chondrite. The author collects and organizes basic information about these findings and compares the latest data with statistics from previous years. The description of the circumstances of finding meteorites are brief and maintained in the popular-scientific tone. The text also includes a set of fireballs and bolides that could end with a meteorite fall. Among them is also a bolide that was visible from Poland. The thesis resembles the criteria for dividing meteors and notes the differences in their naming. It is extended by analogies and comparisons that make possible to look at the issues from different perspectives: from the statistical, through the media, to the historical one.
EN
In 2019 two meteorite showers occurred on Earth, which ended with the fall of hundreds of fragments in Cuba and Costa Rica. Apart from them, meteorites with a total weight of probably less than 10 kg landed in Algeria, Morocco, Iran, India, and Germany. This work is another summary of the year in terms of meteorite falls. It includes information on the circumstances of these phenomena and their scientific consequences. The author collected information from many sources, especially the media and meteorite hunters, to describe in a brief form how the meteorites fell last year. The purpose of his work is to gather basic and proven knowledge, which can serve as an inspiration to further explore the history of meteorites, own meteorite hunting, and draw the attention of researchers to interesting falls in distant regions of the world.
EN
In this article the authors present a simple method of determining the content of selected metal raw materials (Fe, Ni, Co) on the parent bodies of ordinary chondrites. Thanks to the use of planimeter for measuring, under microscope, polished slices of meteorites, it is possible to estimate quite accurately the proportion of these metals in the parent bodies of meteorites, i.e. on asteroids. When it comes to analysing a large number of polished slices, these results will be most likely comparable to much more expensive results of chemical tests conducted on meteorites. Based on the analysis of 16 thin polished sections and polished slices of 11 ordinary chondrites, the authors found out that the highest content of Fe, Ni and Co ore minerals, reaching 10,06% of the total volume, can be found in ordinary chondrites from group H. For ordinary chondrites from groups L and LL, it makes 3,86% and 3,93% of the volume respectively. Employing the results of chemical analyses available in literature sources, the authors also estimated the size of Fe, Ni and Co resources for several selected asteroids. These bodies contain higher concentrations of iron, nickel and cobalt than terrestrial deposits (those found in the earth’s crust). The total content of Fe on parent bodies of even the most deficient in metals group LL of ordinary chondrites is about twice as high as that in the earth’s crust. Cobalt occurs on parent asteroids of ordinary chondrites in concentrations 15–24 times as high as those in the earth’s crust, and the concentrations of Ni are 100–180 times as high as those in the earth’s crust. The contents of these metals on parent asteroids of ordinary chondrites are also several times as high as those in currently extracted deposits in the earth’s crust. Taking into account the mean annual terrestrial production of these metals, the authors have estimated that a parent asteroid of ordinary chondrites with the size between 433 Eros and 6 Hebe could satisfy our need for Fe, Ni and Co for the nearest several million to dozens of billion years. Considering the fact that asteroid belt contains plenty of such objects, and as many asteroids built chiefly of Fe-Ni alloy, one should regard this section of the Solar System as a practically inexhaustible source of metal raw materials. The prospect of their exploitation is probably much nearer than we can currently imagine.
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