The main asteroid belt spanning approximately 2-4 AU in heliocentric distance serves as a
sparse repository of rocky debris offering invaluable insights into the solar system's past.
Evidence drawn from the dynamical structure of both the main belt and the Kuiper belt beyond
Neptune suggests a narrative of planetary migration wherein the giant planets initially
existed in a more compact formation before experiencing migration driven by planetesimals. This
migration event swept both mean motion and secular resonances across the main asteroid belt
inducing a rise in asteroid eccentricity and depletion of the belt itself. Examination of
present-day distributions of large main belt asteroids aligns with this narrative offering
further support for resonance sweeping during the epoch of giant planet migration. Utilizing an
analytical model of ni6 secular resonance sweeping constraints on Saturn's migration speed can
be inferred. Post-migration dynamical chaos emerged as the primary loss mechanism for
asteroids with diameters exceeding 10 km with a logarithmic decay law effectively describing
the dynamical loss history of test particles from this region. This model implies a potential
decline in the rate of impacts from large asteroids over the last approximately 3 billion years
suggesting a present-day impact flux significantly lower than previously estimated impacting
crater chronologies and hazard risk assessments. Additionally quantification of the solar
wind's 6Li 7Li ratio reflects the influx of chondritic material and enhanced dust production
during planetesimal-driven giant planet migration contributing to the current depletion of
lithium in the solar photosphere relative to chondrites. The expectation of 6Li being less
abundant in the sun compared to 7Li due to differing nuclear reaction rates further supports
this narrative. Furthermore evidence pointing to a short-lived impact cataclysm affecting the
entire inner solar system may be discernible in the composition of implanted solar wind
particles in lunar regolith offering yet another layer of insight into the tumultuous history
of our celestial neighborhood.
