26 Gennaio 2022, 11:00
Title: The near-Earth cosmic dust complex: perspectives from the Transantarctic Mountains micrometeorite collection.
Speaker: Prof. Luigi Folco da Dipartimento di Scienze della Terra, Università di Pisa
Abstract:
Some 40,000 tons of cosmic dust enters the Earth’s atmosphere each year, dominating the annual mass influx of extraterrestrial material accreting on our planet today. Cosmic dust consists of microscopic particles typically less than a few millimeters in size, moving in the interplanetary space of the solar system. These are mainly produced by collisions among solid bodies and by surface sublimation of icy bodies, including asteroids, comets, and possibly terrestrial planets and their moons. Whether the principal sources of interplanetary dust are asteroids or comets, and how and why the global influx of extraterrestrial materials has varied through Earth’s history are highly debated within the Earth and planetary science community. After a general introduction on the why we study cosmic dust, I will provide an overview of how our team’s micrometeorite research in Antarctica has contributed to this field of study since the discovery of the Transantarctic Mountain micrometeorite collection in 2003, within the framework of the Italian Programma Nazionale delle Ricerche in Antartide (PNRA). In particular, I will focus on the role of this collection in the definition of the composition of the near-Earth interplanetary dust complex, the geology of the parent bodies and flux studies.