Abstract DGP2026-42

MiMiTracer: Constraining the Cosmic Origin of Micrometeorites

Carl W. Fenski (1,2), Jenny Feige (1), Alessandro Airo (1), Andrea Miedtank (1,3), Beate Patzer (2)

(1) Museum für Naturkunde Berlin, Germany, (2) Technische Universität Berlin, Germany, (3) Freie Universität Berlin, Germany

Micrometeorites (MMs) constitute a continuous flux of extraterrestrial material to Earth and preserve cosmogenic radionuclide signatures that encode their irradiation and transport histories in the Solar System. During inward migration driven by the Poynting–Robertson (PR) effect, MM progenitors accumulate cosmogenic radionuclides such as Al-26 and Be-10 at rates that depend on heliocentric distance, composition, shielding depth, and orbital evolution (e.g., [1–4]).

We present MiMiTracer, an irradiation–transport modeling framework that couples PR–driven orbital decay with cosmogenic nuclide production by galactic and solar cosmic rays (GCRs and SCRs). Building on earlier approaches [3–5], MiMiTracer implements radially dependent and non-isotropic SCR and GCR fluxes, depth-dependent production rates, and particle mass loss during atmospheric entry. Relative to the predecessor model by Feige et al. [1], MiMiTracer explores a substantially expanded parameter space encompassing progenitor size, density, composition, initial heliocentric distance, and dynamical exit criteria, enabling a systematic evaluation of cosmogenic signatures in Al-26–Be-10 space.

Model experiments reveal robust compositional systematics, with Be-10–enriched domains for carbonaceous-chondrite-like material and compact, Al-26–rich fields for ordinary-chondrite-like compositions, alongside structural degeneracies in cosmogenic nuclide space. Comparison of measured nuclide inventories with modeled irradiation trajectories constrains source regions spanning asteroidal reservoirs, near-Earth asteroids, and cometary populations, including Jupiter-family and high-eccentricity cometary dust.

These results demonstrate that MiMiTracer provides a unifying, physically grounded framework for interpreting cosmogenic nuclide records in MMs. Extending the approach to additional nuclides (e.g., Ne-21, Cl-36, Mn-53), solar-wind species, and dynamically self-consistent N-body transport models will further improve constraints on the origin and evolution of extraterrestrial dust across the Solar System.

[1] J. Feige et al. (2024), Phil. Trans. 382.2273.
[2] K. Nishiizumi et al. (1995), Meteoritics 30.6, 728–732.
[3] Trappitsch and Leya (2013), M&PS 48.2, 195–210.
[4] Trappitsch and Leya (2014), 45th AL&PSC.
[5] Love and Brownlee (1991), Icarus 89.1, 26–43.