Figure 4
From: Terrestrial planet and asteroid belt formation by Jupiter–Saturn chaotic excitation
Comparison of our representative asteroid belt constructed based on disk models that yielded terrestrial planet systems analogous to our own (coloured symbols/curves) with 895 large observed asteroids not belonging to asteroid families (greyscale symbols/curves). Model asteroids represent the state after ~ 4.1 Gyr of dynamical evolution. Observed asteroids possess diameters D > 20–30 km (for albedos 0.1–0.2). (a) The representative asteroid belt consists of local primordial asteroids in the protoplanetary disk at < 3.5 au (brown symbols) and asteroids captured from trans-Jovian orbits after giant-planet migration (blue symbols). The proportion of local:captured asteroids is 33%:67%. The curve indicates the location of the secular resonance nu6 (bottom). (b) Both model and observed asteroids are classified as S- (top), C- (middle) and D/P-type asteroids (bottom). The histograms show the relative fractions of asteroid types per semimajor axis bin. The composition model considered the following proportions of S-, C-, D/P-asteroids: S80%-C20% (< 2 au) and S50%-C50% (> 2 au) for local and S5%-C47.5%-DP47.5% for captured asteroids. See Methods and Supplementary Information for details.
