Direct measurement of decimetre-sized rocky material in the Oort cloud

The Oort cloud is thought to be a reservoir of icy planetesimals and the source long-period comets (LPCs) implanted from outer Solar System during time giant-planet formation. abundance rocky ice-free bodies key diagnostic formation models as it can distinguish between ‘massive’ ‘depleted’ proto-asteroid-belt scenarios thus disentangle competing planet models. Here we report direct observation decimetre-sized (~2 kg) meteoroid on retrograde LPC orbit (eccentricity ~1.0, inclination 121°). During its flight, fragmented at dynamic pressures similar fireballs dropping ordinary chondrite meteorites. A numerical ablation model fit produces bulk density properties also consistent with asteroidal meteoroids. We estimate flux objects impacting Earth $$1.0{8}_{-0.95}^{+2.81}$$ meteoroids per 106 km2 yr−1 mass limit 10 g. This corresponds an $$\sim {6}_{-5}^{+13}$$ % all originating in these masses. Our result gives support migration-based dynamical System, which predict that significant material cloud, not explained by traditional Observations coming show made material, constraining ratio $${6}_{-5}^{+13}$$ %.