¹M.E.I.Riebe,¹D.I.Foustoukos,¹C.M.O’D.Alexander,¹A.Steele,¹G.D.Cody,¹B.O.Mysen,¹L.R.Nittler
Earth and Planetary Science Letters 540, 116266 Link to Article [https://doi.org/10.1016/j.epsl.2020.116266]
¹Earth and Planets Laboratory, Carnegie Institution of Washington, 5241 Broad Branch Road, Washington, DC 20015, USA
Copyright Elsevier

Interplanetary dust particles (IDPs) and micrometeorites (MMs) were likely major sources of extraterrestrial organics at the surface of the early Earth. However, these particles experience heating to >500 °C for up to several seconds during atmospheric entry. In this study, we aim to understand the effects of atmospheric entry heating on the dominant organic component in IDPs and MMs by conducting flash heating experiments (4 s to 400 °C, 600 °C, 800 °C, and 1000 °C) on insoluble organic matter (IOM) extracted from the meteorite Cold Bokkeveld (CM2). For each of the experimental charges, the bulk isotopic compositions of H, N, and C were analyzed by IRMS, the H isotopic heterogeneities (occurrence of deuterium hotspots) of the samples were measured by NanoSIMS, and the functional group chemistry and ordering of the IOM was evaluated by using FTIR and Raman spectroscopy, respectively. Organic matter in particles heated to ≥600 °C during atmospheric entry experienced significant alteration. Loss of isotopically heavy, labile H and N groups results in decreases in bulk δD, N, H/C and, upon heating ≥800 °C, in N/C. The H isotopic heterogeneity was not greatly affected by flash heating to ≤600 °C, although the hotspots tended to be less isotopically anomalous in the 600 °C sample than in the 400 °C sample. However, the hotspots all but disappeared in the 800 °C sample. Loss of C=O groups occurred at 800 °C. Based on the Raman G-band characteristics, the heating resulted in increased ordering of the polyaromatic component of the IOM.

The data presented in this study show that all aspects of the composition of organic matter in IDPs and MMs are affected by atmospheric entry heating. Modelling and temperature estimates from stepwise release of He has shown that most IDPs and MMs are heated to >500 °C (Love and Brownlee, 1991; Nier and Schlutter, 1993; Joswiak et al., 2007), hence, atmospheric entry heating is expected to have altered the organic matter in most such particles.

¹O. Unsalan,²A. Bayatlı,^3,4P. Jenniskens
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13469]
¹Department of Physics, Faculty of Science, Ege University, 35100 Bornova, Izmir, Turkey
²History Department, Faculty of Letters, Trakya University, 22030 Edirne, Turkey
³SETI Institute, 189 Bernardo Ave, Mountain View, California, 94043, USA
¹NASA Ames Research Center, Moffett Field, California, 94035 USA
Published by arrangement with John Wiley & Sons

Our planet experiences falls of meteorites with different airburst and ground impact risk. Some of these meteors can survive after the atmospheric passage and fall into the ground. Although there are claims that people were hit and killed by meteorites in history, the historical records do not prove this fact so far. This issue might be due to the fact that either the manuscript was written in a language other than English or there is not enough interest in historical records. To the best of our knowledge, we show the first proof of an event ever that a meteorite hit and killed a man and left paralyzed another on August 22, 1888 in Sulaymaniyah, Iraq, based on three manuscripts written in Ottoman Turkish that were extracted from the General Directorate of State Archives of the Presidency of the Republic of Turkey. This event was also reported to Abdul Hamid II (34th sultan of the Ottoman Empire) by the governor of Sulaymaniyah. These findings suggest other historical records may still exist that describe other events that caused death and injuries by meteorites.