Volatile-element depletion in rocky planets as a purity spectrum of a single information field: An information-dynamics reinterpretation of hybrid accretion

Abstract

Wang et al. (2026, Nature Astronomy) showed that the moderately-volatile lithophile element (MVLE) depletion patterns of Earth and Mars record different formation pathways: Earth accreted ≳75% of its mass via pebble accretion, Mars ∼73% via collisions of volatile-depleted planetesimals. We reinterpret this result in the information-dynamics (ID) framework, in which self-organization (ε) and dissipation (γ) compete through a single information field of local purity p. A numerical experiment on the published source data (13 elements for bulk silicate Earth, bulk silicate Mars and Vesta) shows that a single mean purity cannot describe the two planets: the fit escapes to unphysical solutions. The data instead require a purity spectrum: each planet’s pattern is a mixture over one universal single-purity response law S(T ; p), with only the mixture weights differing between bodies. A joint fit with a 4-parameter universal law reproduces all 36 data points with χ2/N = 0.35 (all residuals within 2σ). The inferred spectra mirror the published multi-component decomposition (Earth: 59% strongly-processed + 24% Vesta-like + 17% volatile-rich; Mars: Vesta-like bin dominant), and Vesta independently concentrates 99% of its weight at a processing temperature of 1116K, reproducing the published 1135±35K without being given it. Pebble accretion and planetesimal collision thus emerge as two projections of the same field at different purities, rather than two independent mechanisms. We give testable predictions for rocky exoplanets and the Moon.