Extended Data Fig. 6: Variation of the Root-Mean-Square Deviation (RMS) to the observed elemental abundances as a function of the three randomised variables in 1000 Monte Carlo simulations.
The four N-body simulations are organised by row, in which the RMS is plotted on the ordinate axis and the value of the random variable on the abscissa, organised by column (mass accretion rate (\(\dot M\)), mean atmospheric mass (mi) and embryo feeding zone (σembryo). Although the goodness of fit is nearly independent of σembryo and mi, it has a well-defined minimum as a function of mass accretion rate. The mass accretion rate defined by this minimum varies only marginally among the four N-body simulations, with a mean of 1.08(±0.17)×10−7 solar masses/year, demonstrating that the composition of the fully accreted Earth analogue is largely sensitive to the initial compositions of its constituents, which are in turn set by the temperatures (and hence heliocentric distances) at which they were formed.
