On the cooling rate evolution of asteroid fragments

Recent observations of rapid cooling rates at high temperatures in several ordinary chondrite and primitive achondrite meteorite groups suggest the fragmentation their parent bodies near peak temperatures. We use analytic models for conductive collisional fragments to show that actively part a fragment experiences similar over large range This characteristic rate decays inversely with time larger longer this decay continues. Measurements temperature therefore place lower bound on size fragments. Applying model H chondrites , which vary from 1 0 ? 2 °C/yr between 700 850 °C, we estimate times least 10 4 years 3 m radius. • Conductive constant declines as 1/time. High-temperature data provide constraint time. size. H-chondrite exceed dynamical estimates reassembly