Characterization of Potential Micrometeorites by Synchrotron Analysis

• Main Authors: Madison Esposito, Kevin Souhrada, Erin Garland, Mary Kroll, Robert Bolen, Victoria Hernandez, Janet Kaczmarek, David Meisel, Anya Swiss, Paul Northrup, Vivian Stojanoff, Juergen Thieme, Aleida Perez
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Geosciences
• Subjects: micrometeorites; meteorites; synchrotron; X-ray fluorescence; X-ray absorption spectroscopy; X-ray diffraction
• Online Access: https://www.mdpi.com/2076-3263/10/7/275

Micrometeorites (MMs) are small particles that account for most of the extraterrestrial material deposited on Earth. Synchrotron X-ray fluorescence and diffraction allowed for chemical and mineral characterization to distinguish MM from atmospheric particulate. The relative components of iron, nickel, and other elements were considered in the identification of ferrous MM while high amounts of titanium were considered an indication that the particles were of atmospheric origin. Out of 100 samples collected by high school students and teachers, eight were taken to a synchrotron for analysis. Of those eight, three exhibited extraterrestrial compositions. X-ray absorption near-edge structure analysis revealed that the same three samples contained sulfide, the main sulfur form constituent in MM. X-ray microdiffraction analysis showed the presence of the minerals pentlandite and forsterite. Collectively, these results support the extraterrestrial nature of the three particles.