Cosmogenic radionuclides in the Antonin meteorite

The Antonin meteorite fell on July 15, 2021 in Wielkopolska Voivodeship. Its fall was recorded by fireball camera network and the meteorite specimen was recovered soon after, during a dedicated search expedition. Main mass of Antonin was provided for scientific research relatively quickly after recovery, thanks to which the studies of cosmogenic radionuclide concentrations were carried out in the g spectrometry laboratory at the National Center for Nuclear Research in Otwock/Świerk. The analyses revealed concentration of 7Be and the traces of the cosmogenic radionuclides of 48V and 51Cr, whose half-lives are in the range of 15–28 days, clearly confirming the relationship of the specimen with the observed fireball. The relatively high concentrations of 58Co, 56Co, 46Sc, 57Co and 54Mn (half-lives of several months) also confirm the recent fall of the specimen. Additionally, collected radionuclide data allow to estimate pre-atmospheric size of the meteoroid. Distribution of 60Co and 26Al indicates a meteoroid chunk with a radius of 20–25 cm. The result of 26Al measurement suggests that the investigated meteorite fragment comes from a rather shallow depth of this meteoroid. In addition, the original mass of the meteoroid from which the Antonin meteorite originated was estimated to be less than 100 kg, most likely 70 kg

The chondrite breccia of Antonin (L4‐5)—A new meteorite fall from Poland with a heterogeneous distribution of metal

On July 15, 2021, a huge fireball was visible over Poland. After the possible strewn field was calculated, the first and so far only sample, with a mass of 350 g, was discovered 18 days after the fireball event. The Antonin meteorite was found August 3, 2021, on the edge of a forest close to a dirt road near Helenow, a small suburb of the city of Mikstat. The rock is an ordinary chondrite breccia and consists of equilibrated and recrystallized lithologies. The boundaries between different fragments are difficult to detect, and the lithologies are of petrologic type 5 and type 4. The rock is moderately shocked (S4) and contains local impact melt areas and thin shock veins. The low‐Ca pyroxene and olivine are equilibrated (Fs20.6 and Fa24.0, respectively), typical of L chondrites. The L chondrite classification is also supported by O isotope data and the results of bulk chemical analysis. The Ti isotope characteristics confirm that Antonin is related to the noncarbonaceous (NC) meteorites. One of the studied thin sections shows an unusual metal–chondrule assemblage, perhaps indicating that the metal in the chondrite is heterogeneously distributed, which is, however, not clearly visible in the element abundances.Alexander von Humboldt‐Stiftung http://dx.doi.org/10.13039/100005156Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/50110000165

The chondrite breccia of Antonin ( L4 ‐5)—A new meteorite fall from Poland with a heterogeneous distribution of metal

On July 15, 2021, a huge fireball was visible over Poland. After the possible strewn field was calculated, the first and so far only sample, with a mass of 350 g, was discovered 18 days after the fireball event. The Antonin meteorite was found August 3, 2021, on the edge of a forest close to a dirt road near Helenow, a small suburb of the city of Mikstat. The rock is an ordinary chondrite breccia and consists of equilibrated and recrystallized lithologies. The boundaries between different fragments are difficult to detect, and the lithologies are of petrologic type 5 and type 4. The rock is moderately shocked (S4) and contains local impact melt areas and thin shock veins. The low-Ca pyroxene and olivine are equilibrated (Fs20.6 and Fa24.0, respectively), typical of L chondrites. The L chondrite classification is also supported by O isotope data and the results of bulk chemical analysis. The Ti isotope characteristics confirm that Antonin is related to the noncarbonaceous (NC) meteorites. One of the studied thin sections shows an unusual metal–chondrule assemblage, perhaps indicating that the metal in the chondrite is heterogeneously distributed, which is, however, not clearly visible in the element abundances