The late formation of chondrites as a consequence of Jupiter-induced gaps and rings

Abstract

The accretion ages of the first planetesimals-the parent bodies of magmatic iron meteorites-suggest they formed within the first 0.5-1 Myr of Solar System history. Yet, planetesimal formation appears to have occurred in at least two distinct phases. A temporal offset separates early-forming bodies from later-forming chondrite parent bodies, which accreted 2-3 Myr after the Solar System onset - an unresolved aspect of Solar System formation. Here we use numerical simulations to show that Jupiter's early formation reshaped its natal protoplanetary disk. Jupiter's rapid growth depleted the inner disk gas and generated pressure bumps and dust traps that manifested as rings. These structures caused dust to accumulate and led to a second-generation planetesimal population, with ages matching those of non-carbonaceous chondrites. Meanwhile, the evolving gas structure suppressed terrestrial embryos' inward migration, preventing them from reaching the innermost regions. Jupiter likely played a key role in shaping the inner Solar System, consistent with structures observed in Class II and transition disks.

Figures (13)

• Figure 1: Schematic illustration of the proposed evolutionary scenario for the early inner Solar System over the first $\sim$3 Myr. (A) At early times ($t \sim 0.1$ Myr), radial drift and turbulent mixing transport dust grains across the disk. (B) Around $\lesssim 0.5 - 1$ Myr, primordial planetesimal formation occurs in ringsizidoro_planetesimal_2022morbidellietal22. (C) By $\sim$1.5 Myr, growing planetary embryos start to migrate inward under the influence of the gaseous protoplanetary disk, while Jupiter's core enters rapid gas accretion phase. (D) Around $\sim$2 Myr, Jupiter’s gravitational perturbations excite spiral density waves, inducing pressure bumps in the inner disk. Giant impacts among migrating embryos generate additional debris. Pressure bumps act as dust traps, halting inward drift of small solids and leading to dust accumulation. (E) Between $\sim$2–3 Myr, dust accumulation at pressure bumps leads to the formation of a second generation of planetesimals. Rapid gas depletion in the inner disk, combined with the presence of these traps, limits the inward migration of growing embryos. (F) By $\sim$3 Myr, the inner gas disk is largely dissipated, resulting in a system composed of terrestrial embryos and a second generation of planetesimals—potentially the parent bodies of ordinary and enstatite chondrites—while the inner disk evolves into a gas-depleted cavity.
• Figure 2: Snapshots showing the formation of pressure bumps and gaps in a hydrodynamical simulation with a Jupiter-mass planet placed at 5.4 au. The initial surface density profile corresponds to a power-law disk following the classical Minimum Mass Solar Nebula (MMSN) diskweidenschilling_aerodynamics_1977hayashi81. The disk extends from 0.2 au to 40 au, the gas viscosity is set to $\alpha=10^{-5}$, and we use free-outflow boundary conditions. During the entire course of the simulation, Jupiter is kept in a non-migrating orbit, as indicated by the vertical dashed line. The vertical axis represents the normalized gas surface density relative to the initial surface density profile. The disk model employs a logarithmic spacing for radial resolution, consisting of 1240 radial and 1400 azimuthal cells. At 1 au, the disk resolution yields about 12 cells per scale height.
• Figure 3: Normalized inner gas disk mass over time in hydrodynamical simulations with and without Jupiter. The vertical axis represents the mass within the inner disk ($r<5.4$ au), normalized to its initial value. The blue curve corresponds to the simulation, including Jupiter, while the red curve represents the simulation without it. The dot-dashed and dashed lines indicate the fitted exponential depletion timescales for each scenario. In the presence of Jupiter, the inner disk depletes with a timescale of 0.3 Myr --approximately seven times faster than the 2 Myr depletion timescale observed in the simulation without Jupiter.
• Figure 4: Growth-migration tracks of planetary embryos growing via planetesimal accretion and mutual impacts in simulations with Jupiter forming at varying times and without Jupiter. Each simulation begins with 40 planetary embryos, each with a mass of $10^{-4}$ M$_\oplus$, embedded in a disk of $\sim$100 km-sized planetesimals initially distributed between 0.8 and 1.5 au (see Methods). Before Jupiter forms, gas disk dissipation follows an e-fold timescale of 2 Myr. Upon Jupiter's formation, this timescale shortens to 0.3 Myr to reflect the accelerated depletion observed in our hydrodynamical simulations. The grey lines trace the evolution of planetary embryos in mass and semi-major axis, while black circles denote their final masses and positions. The color bar indicates normalized torques acting on the embryos (a migration map): blue regions correspond to outward migration, red to inward migration, and the black contour marks zero-torque regions. The underlying migration map evolves as Jupiter grows. The contours shown here correspond to the time when Jupiter is completely formed. The four panels represent different scenarios, each corresponding to a distinct timing of Jupiter’s formation. From top to bottom: (A) a power-law disk without Jupiter, (B) Jupiter forming at 2 Myr, (C) at 1.5 Myr, and (D) at 1 Myr. The grey area marks the region inside Mercury's orbit.
• Figure 5: Snapshots of surface densities of gas (brown), dust (yellow), and planetesimals (blue) from a dust advection-diffusion simulation including planetesimal formation. The initial surface density follows an MMSN-like disk profile, with no dust initially present in the disk. Dust is introduced between 0.7 and 2.0 au, as calibrated from the results of simulation modeling collisional evolutionizidoro_planetesimal_2022. The top-left panel shows the disk after 2000 years from the start of the simulation (0.502 Myr relative to CAIs) - showing a small amount of dust present. As in previous simulations, the gas disk initially dissipates following an exponential decay with a timescale of 2 Myr. Jupiter starts to form at 1.5 Myr, and we subsequently reduce the depletion timescale to 0.3 Myr. As Jupiter forms, pressure bumps appear and continue to develop until 2 Myr (see Methods). Pressure bumps facilitate dust trapping, triggering planetesimal formation starting at around 2.3 Myr. The bottom-right panel shows the final reservoirs of planetesimals -- labeled A, B, and C -- that are generated by the end of the gas disk phase.