Pith. sign in

REVIEW 3 major objections 4 minor 67 references

Dynamical origin of Theia, the last giant impactor on Earth

T0 review · 3 major / 4 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read This paper uses N-body simulations to argue that Theia, the Moon-forming impactor, had roughly 50-50 odds of being a carbonaceous body, and that the required carbonaceous tail must have carried 0.2-0.3 Earth masses mostly in embryos.

desk verdict A transparent and useful N-body test of a carbonaceous Theia, but the headline 50-50 odds are computed over systems that mostly fail the Mars constraint and are likely overstated until conditioned. read the letter →

arxiv 2507.01826 v1 pith:IOTHVNIO submitted 2025-07-02 astro-ph.EP

classification astro-ph.EP
keywords terrestrialplanetformationMoon-formingimpactTheiacarbonaceouschondritesN-bodysimulationslateaccretionisotopicdichotomy
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper asks whether Theia, the Mars-sized body whose collision with proto-Earth created the Moon, could have been made of carbonaceous (CC) material from the outer Solar System, as some meteorite isotope studies have proposed. To answer this, the authors run N-body simulations of late-stage terrestrial planet formation that start from a standard annulus of rocky embryos and planetesimals and also inject a tail of carbonaceous embryos and planetesimals scattered inward by Jupiter. They find that the scenario is dynamically viable only if the injected carbonaceous mass was about 0.2-0.3 Earth masses and was dominated by embryos rather than planetesimals. Under that condition, about half of their viable simulations give Earth a final giant impactor that contains carbonaceous material, either as a pure CC embryo or as a rocky embryo that had previously swallowed a CC embryo. The result matters because it would turn a cosmochemical hypothesis about the Moon's birth into a concrete, testable dynamical outcome.

What carries the argument

The load-bearing machinery is the mixed-scenario set of N-body simulations of terrestrial planet formation: a standard narrow annulus of non-carbonaceous embryos and planetesimals from 0.7 to 1.2 AU, plus 15 carbonaceous embryos of 1-2% Earth masses and 500 carbonaceous planetesimals carrying 0.04 Earth masses, with perihelia between 0.7 and 1.5 AU and aphelia within 5.5 AU, representing material scattered inward by Jupiter and Saturn. The simulations track which bodies collide with the growing planets and when. The annulus model provides the baseline terrestrial-planet architecture; the injected carbonaceous tail supplies the ingredient whose mass and embryo-to-planetesimal split are tuned; and the criteria of radial mass concentration and angular momentum deficit identify which runs count as viable Solar System analogs.

What would settle it

A concrete way to test the claim would be to measure nucleosynthetic isotope anomalies (for example molybdenum, ruthenium, or titanium) in lunar samples that carry the Moon-forming impactor's signature: if the Moon is found to carry no carbonaceous component, the roughly 50-50 prediction for a carbonaceous Theia would be very hard to sustain. A second, dynamical falsifier would be a demonstration that Jupiter could not scatter 0.2-0.3 Earth masses of carbonaceous material into the terrestrial region during its gas-accretion phase.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central discovery is that a dynamical model of terrestrial accretion can reproduce Earth's roughly 5-10% carbonaceous mass fraction and Mars's much smaller one while simultaneously making it common for the last giant impactor on Earth to be carbonaceous. In the mixed scenario without an early giant-planet instability, 38.5% of simulations ended with a pure CC embryo as Earth's final impactor and another 13.5% with a non-carbonaceous embryo that had previously accreted a CC embryo, so a carbonaceous-bearing Theia occurred in more than half of cases. The same simulations also produced Earth analogues with about 6% CC mass, Mars analogues with under 1% CC mass when no CC embryo struck Mars, a Moon-forming impact timing of 20-70 Myr in most realizations, and a late accretion phase dominated by dry, non-carbonaceous material, in line with cosmochemical data.

Load-bearing premise

The entire result rests on the assumed initial population of carbonaceous objects: a prescribed set of embryos and planetesimals with chosen masses and orbits is inserted as a proxy for material scattered inward by the giant planets, rather than being produced self-consistently by a model of Jupiter's growth and migration; if that injected population is wrong, the 50-50 odds for a carbonaceous Theia change.

Editorial extensions

If this is right

  • If the scenario is right, cosmochemical arguments that Theia was carbonaceous are dynamically supported, not just isotopically inferred.
  • The required scattered carbonaceous mass of 0.2-0.3 Earth masses and an embryo-to-planetesimal mass ratio of at least 8 become constraints on the outer Solar System's primordial planetesimal reservoir and on how efficiently the giant planets' cores formed.
  • Mars's low carbonaceous fraction would be explained as a stochastic outcome: Mars avoids carbonaceous embryos most of the time, while Earth does not, because of the embryo-dominated mass distribution.
  • The Moon-forming impactor need not have been a single large carbonaceous embryo; it could have been a rocky embryo that gained its carbonaceous material earlier, which widens the range of allowed impactor masses.
  • A late accretion phase dominated by dry, non-carbonaceous planetesimals follows naturally, consistent with the volatile-depleted late veneer inferred from the Earth-Moon system.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Inference: the 50-50 odds imply a statistical prediction, namely that a population of similar terrestrial-planet systems should show late giant impactors with carbonaceous isotopic signatures in roughly half of cases.
  • Inference: replacing the imposed carbonaceous initial conditions with a self-consistent model of gas-drag-assisted inward scattering during Jupiter's growth would either confirm the 0.2-0.3 Earth-mass requirement or reveal it as an artifact of the proxy.
  • Inference: the embryo-to-planetesimal ratio of at least 8 suggests that the outer Solar System held several Earth masses of unaccreted embryos near Jupiter and Saturn, a population that might be connected to captured irregular satellites or Trojans, though the paper does not model those bodies.
  • Inference: applying the same mixed-scenario approach to exoplanetary systems could predict a correlation between a rocky planet's measured volatile budget and the probability that its last giant impactor carries a carbonaceous isotopic signature.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 4 minor

Summary. The paper tests, with N-body simulations of late-stage terrestrial accretion, the cosmochemical proposal that Earth's final giant impactor (Theia) was a carbonaceous (CC) object. Starting from a narrow-annulus population of NC embryos and planetesimals, the authors add inward-scattered CC planetesimals and embryos in three scenarios (small-only, large-only, and mixed), with a subset of runs imposing a simplified giant-planet instability at 20 Myr. They report that the mixed scenario with no instability can match several Solar System constraints, and that in slightly more than half of those runs Earth's last giant impactor contains a CC component: 38.5% as a pure CC embryo and 13.5% as an NC embryo that previously accreted a CC embryo. They interpret this as roughly 50-50 odds that Theia was carbonaceous and derive constraints on the total scattered CC mass and embryo-to-planetesimal mass ratio.

Significance. If the central claim is robust, the paper provides a dynamical validation of a specific and debated cosmochemical scenario, and it sharpens the discussion of how Earth's carbonaceous budget was delivered. The study is transparent about its main simplifications, uses a standard integrator and standard initial-condition choices, and directly compares three different CC delivery populations, which is a useful approach. However, the headline quantitative claim depends on a statistical conditioning that the paper does not report, and the derived 'constraints' are closely tied to hand-tuned input choices; these issues are load-bearing for the abstract's claim rather than mere presentational shortcomings.

major comments (3)
  1. [Sec. 3.3 and Sec. 3.2] The headline 50-50 probability for a carbonaceous Theia is computed over a set of runs that includes many systems violating the paper's own Mars constraint. Section 3.3 reports 38.5% pure-CC and 13.5% mixed-CC final impactors, but Section 3.2 states that in 62.5% of the mixed runs satisfying the Earth/Mars mass-ratio selection, the Mars analog was hit by a CC embryo and its CC fraction jumped above 10%, inconsistent with the observed Mars CC fraction of at most a few percent. The paper does not report the conditional probability P(carbonaceous Theia | Mars CC fraction <= 2-3%). Since the abstract describes these as 'viable systems,' the odds should be computed only on runs that pass the Mars constraint, or at minimum the conditional and unconditional numbers should both be given. This is a direct internal statistical gap rather than an external modeling assumption.
  2. [Sec. 2.2 and Sec. 4] The paper presents ~0.2-0.3 Earth masses of total CC material and an embryo-to-planetesimal mass ratio of about 8 as constraints, but these values are largely imprinted by the hand-tuned initial conditions. The mixed scenario was initialized with 15 CC embryos of 1-2% Earth masses and 0.04 Earth masses of CC planetesimals, with the authors stating that they 'adjusted the mass of CC objects to try to keep the mass of the terrestrial planets close to their actual values.' The later estimate of an ~8:1 ratio and the total CC mass is then derived from the same simulations, so it is a back-calculation rather than an independent constraint. To support the abstract's claim that 'for this scenario to work' these values are required, the paper should test the sensitivity of the outcome to the assumed number, mass, and orbital distribution of CC embryos and planetesimals, or at least explicitly frame these as posterior properties of the chosen model rather than as robust constraints.
  3. [Sec. 2.2 and Sec. 3.3] The 50-50 odds are sensitive to the imposed orbital distribution of CC bodies, which is not varied or self-consistently produced. All mixed runs place CC embryos with perihelia uniformly drawn between 0.7 and 1.5 AU and aphelia up to 5.5 AU; this directly sets how many CC embryos are initially on Earth-crossing orbits and therefore controls the probability of a CC-bearing final impactor. The paper acknowledges that the injection is not modeled self-consistently, but it does not quantify how the headline probability would change under plausible alternative distributions (e.g., a population more concentrated near the asteroid belt or delivered later). This is a load-bearing uncertainty for the claim that there are 'roughly 50-50 odds' rather than merely for the precise value of the probability.
minor comments (4)
  1. [Highlights and Abstract] The extracted text contains numerous missing spaces and typographical artifacts (e.g., 'WeranN-bodysimulations', 'inroughly50%', 'mixedsimulations'); the manuscript should be carefully proofread before publication.
  2. [Sec. 3.2] The terminology is inconsistent: the paper refers to the 'large only' scenario in Section 2.2 and elsewhere to the 'big only' scenario in Section 3.2; these should be unified.
  3. [Figure 8] The denominators for the reported percentages (38.5%, 13.5%) are not stated in the caption or text; the reader cannot tell whether these are fractions of all 60 runs, of the 41 runs with Earth analogs, or of some other subset. This should be stated explicitly, and binomial confidence intervals should be given for the headline proportion.
  4. [Sec. 3.4 and Figure 11] The discussion of late accretion would benefit from a quantitative statement of how many of the mixed runs actually satisfy the NC-dominated late-accretion constraint, since Figure 11 shows a range of outcomes and the text describes only general trends.

Circularity Check

1 steps flagged · score 4.0 of 10

Partial circularity: the inferred CC mass and embryo:planetesimal constraints are back-calculated from the assumed CC population and observed fractions, but the Theia-composition odds are an emergent N-body result.

  1. fitted input called prediction [Sec. 4 (Summary and Discussion), 'Using our results as a guide...' paragraph; initial conditions in Sec. 2.2]
    "Using our results as a guide, we can estimate the initial mass in CC planetesimals relative to CC embryos as follows. ... adopt a Mars total CC mass fraction of ~0.5% and a value of ~6% for Earth. ... There must therefore have been ~8 times more mass in CC embryos than in CC planetesimals. ... Put together, this reasoning implies that the total mass in CC material injected into the inner Solar System was ~0.2-0.3 M⊕, with a ~8:1 mass division between embryos and planetesimals."

    The mixed scenario was initialized with 15 CC embryos of 1-2% Earth masses (total 0.15-0.30 M⊕) and 500 CC planetesimals of total 0.04 M⊕, so the total CC mass and embryo:planetesimal ratio were inputs (0.19-0.34 M⊕; roughly 4-7.5:1). The 'constraint' in Sec. 4 is obtained by inserting the same observed Earth and Mars CC fractions used to motivate the scenario into the simulation's median accretion fractions, recovering essentially the assumed total mass and an even stronger embryo dominance. The abstract presents this back-calculation as a necessary condition ('For this scenario to work, the total mass ... must have been ~0.2-0.3 M⊕'), so the claimed constraint is not an independent prediction but a restatement of the chosen population combined with the target observations.

full rationale

The central dynamical claim—that Earth's last giant impactor contains a CC component in roughly half of the mixed no-instability runs—is an emergent outcome of N-body integrations and is not itself fixed by the initial CC population; the same population can produce dry, pure-CC, or mixed final impactors. I therefore do not regard the 50-50 headline as circular. However, the paper's stated 'constraints' on the total CC mass and embryo:planetesimal ratio are weaker: the model was set up with a CC population in that range, and the Section 4 estimate uses the same observed Earth/Mars CC fractions as inputs, so those constraints are consistency conditions rather than independent predictions. The paper is transparent about imposing the CC population rather than modeling its injection self-consistently, and the Mars-conditioning issue raised by the skeptic is a statistical limitation, not a circularity. On balance: one partial circularity in a secondary constraint, while the central claim remains independent.

Assumptions & free parameters 11 free parameters · 6 assumptions · 0 invented entities

The central claim rests on a large set of chosen initial conditions: the annulus parameters, the CC mass budget, the number and mass of CC embryos, and the simplified instability treatment. No new physical entities are invented. The most load-bearing free parameters are the CC total mass and the CC embryo population, which are tuned to reproduce Earth's observed CC fraction.

free parameters (11)
  • Annulus radius = 0.7 to 1.2 AU
    Chosen to reproduce the terrestrial planet masses and orbits; not derived from first principles.
  • Surface density normalization Σ1 = 20.48 g/cm^2
    Chosen to set total embryo/planetesimal mass; adjusted to match solar system.
  • Total NC embryo mass = 2 M⊕
    Set to form Earth-mass planets; part of the tuned annulus model.
  • Total NC planetesimal mass = 0.25 M⊕
    Tuned to keep Mars small and match late accretion.
  • CC total mass in mixed scenario = 0.19-0.34 M⊕
    Adjusted so Earth analogs acquire about 6% CC mass; key free parameter for the central claim.
  • Number of CC embryos = 15 (mixed) or 25 (large only)
    Chosen ad hoc to yield a plausible collision probability; authors state number is higher than expected for Mars-mass embryos.
  • CC embryo mass range = 1-2% M⊕
    Chosen to be large enough to be scattered onto planet-crossing orbits but small enough to avoid too many Mars hits.
  • CC planetesimal total mass (mixed) = 0.04 M⊕
    Set to maintain NC-dominated late accretion; part of the tuned CC mass budget.
  • CC orbital distribution = q in 0.7-1.5 AU, i Rayleigh σ=2.5, Q≤5.5 AU
    Adopted from O'Brien et al. (2014) as a proxy for scattered CC bodies; not derived from a scattering model.
  • Giant planet instability timing = 20 Myr
    Chosen as an intermediate value; the paper notes the timing is uncertain.
  • Jupiter and Saturn initial orbits = a=5.43, 7.30 AU, 3:2 resonance
    From migration models; not varied.
assumptions (6)
  • domain assumption The annulus model (narrow ring of embryos and planetesimals) is a valid starting point for terrestrial planet formation.
    Invoked in Sec 2.1 following Hansen (2009) and others; not derived.
  • domain assumption Carbonaceous material was scattered inward by Jupiter and Saturn's rapid gas accretion and can be represented by an initial population of CC embryos and planetesimals on planet-crossing orbits.
    Assumed in Sec 2.2 based on Raymond and Izidoro (2017a); the paper does not model the scattering self-consistently.
  • domain assumption The NC/CC isotopic dichotomy maps to inner/outer solar system material as commonly assumed.
    Used throughout to label material; from Kruijer et al. (2017).
  • ad hoc to paper The giant planet dynamical instability can be approximated by an instantaneous jump of Jupiter and Saturn to their present-day orbits at 20 Myr.
    Sec 2.3; the paper calls this 'very simply mimicked' and acknowledges it is highly simplified.
  • domain assumption Planetesimals do not interact gravitationally with each other (test particle approximation).
    Sec 2.1.1; standard in this type of N-body simulation.
  • domain assumption Collisions are treated as inelastic mergers.
    Sec 2.1.1; no fragmentation or hit-and-run is modeled.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Dynamical origin of Theia, the last giant impactor on Earth." pith.science (2026). https://pith.science/paper/IOTHVNIO

@misc{pith2026250701826,
  author       = {Pith},
  title        = {Pith review of: Dynamical origin of Theia, the last giant impactor on Earth},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/IOTHVNIO}},
  note         = {Machine review of arXiv:2507.01826}
}
abstract

Cosmochemical studies have proposed that Earth accreted roughly 5-10% of its mass from carbonaceous (CC) material, with a large fraction delivered late via its final impactor, Theia (the Moon-forming impactor). Here, we evaluate this idea using dynamical simulations of terrestrial planet formation, starting from a standard setup with a population of planetary embryos and planetesimals laid out in a ring centered between Venus and Earth's orbits, and also including a population of CC planetesimals and planetary embryos scattered inward by Jupiter. We find that this scenario can match a large number of constraints, including i) the terrestrial planets' masses and orbits; ii) the CC mass fraction of Earth; iii) the much lower CC mass fraction of Mars, as long as Mars only accreted CC planetesimals (but no CC embryos); iv) the timing of the last giant (Moon-forming) impact; and v) a late accretion phase dominated by non-carbonaceous (NC) bodies. For this scenario to work, the total mass in scattered CC objects must have been ~ 0.2 - 0.3 M$_{\oplus}$ , with an embryo-to-planetesimal mass ratio of at least 8, and CC embryos in the ~ 0.01 - 0.05 M$_{\oplus}$ mass range. In that case, our simulations show there are roughly 50-50 odds of Earth's last giant impactor (Theia) having been a carbonaceous object - either a pure CC embryo or an NC embryo that previously accreted a CC embryo. Our simulations thus provide dynamical validation of cosmochemical studies.

Figures

Figures reproduced from arXiv: 2507.01826 by the authors.

Figure 1
Figure 1. Comparisons of 7 simulations with no CC objects from section 2.1 with the real solar system. Left: Mass and semi-major axis are compared. Right: RMC and AMD are compared. 2.2. Simulations including carbonaceous (CC) planetesimals Our next step was to introduce a population of CC objects that were scattered inwards and into intersecting orbits with the terrestrial planets during Jupiter and Saturn’s rapid gas accreti… view at source ↗
Figure 2
Figure 2. Left: Mass and orbital radii of surviving large NC bodies after 200 Myr in all 60 simulations of the mixed scenario. Constraints for planet selection are visualised with the boxes, and the real solar system planets are shown for comparison. Right: The final configuration in the 10 mixed simulations that also included the giant planet instability [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. Normalized angular momentum deficit 𝐴𝑀𝐷 and radial mass concentration 𝑅𝑀𝐶 for the 60 simulations in using the mixed scenario (black) and the 10 giant planet instability ones (blue), as well as a comparison with the real solar system value (red). 3.1. Evolution of an individual simulation In this subsection we present the evolution of a promising Solar System analog simulation from the mixed scenario. We then present… view at source ↗
Figures from the paper (8 more)
Figure 4
Figure 4. Figure 4: Eccentricity and position snapshots over time of a simulation using the mixed scenario where all 4 terrestrial planets fit constraints and the Earth analogue had a final CC embryo impact. Snapshots are shown over time, including the moment after the final giant impact.…
Figure 5
Figure 5. Figure 5: Growth curve of Earth analogue in the simulation from figure 4. Total mass is separated into contribution from NC and CC bodies [PITH_FULL_IMAGE:figures/full_fig_p009_5.png]
Figure 6
Figure 6. Figure 6: Eccentricity and position snapshots over time of the simulation in figure 4 now with the giant planet instability at 20 Myr. The initial NC embryos and planetesimals are shown with the embryos in black and the planetesimals in orange, as well as the CC embryos and plan…
Figure 7
Figure 7. Figure 7: Orbital and CC mass distribution of Earth, Venus and Mars analogues in the mixed sets with CC mass fractions under 14%. Colours represent the mass of the analogue in Earth masses. 3.3. The last giant impact We now address the details of the last giant impacts in our si…
Figure 8
Figure 8. Figure 8: Left: Distribution of 41 final giant impacts with Earth analogues. The blue bars represent the CC embryo final impactor fraction, the green bars are the mixed NC+CC embryo (second order) fraction, while the gray bars represent dry NC embryo fraction. Right: Distributio…
Figure 9
Figure 9. Figure 9: A comparison between the timing of the last giant impacts in 10 mixed simulations simulations that were run both with and without the giant planet instability. The black line represents the point where both values are equal. Each point has two halves with the left half…
Figure 10
Figure 10. Figure 10: Top: Mass distribution of CC impactors on Earth analogues in the mixed sets, in relation to the analogue’s mass at time of impact relative to its final mass. Diamonds are pure CC impactors, while circles are mixed CC+NC impactors with their colour representing their C…
Figure 11
Figure 11. Figure 11: CC mass fraction of late accretion for Earth, Venus and Mars analogues, as a function of the time of the last giant impact (which marks the start of late accretion). The circles and triangles are from the mixed scenario. Squares and diamonds mark the small only simula…

Discussion (0). Sign in to comment.

Reference graph

Works this paper leans on

67 extracted references · 30 canonical work pages

  1. [5]

    Space Science Reviews 205, 41–75

    Dust Evolution and the Formation of Planetesimals. Space Science Reviews 205, 41–75. doi:10.1007/s11214-016-0256-1, arXiv:1604.02952. Bottke, W.F., Walker, R.J., Day, J.M.D., Nesvorny, D., Elkins-Tanton, L., 2010a. Stochastic Late Accretion to Earth, the Moon, and Mars. Science 330,

  2. [7]

    Brasser, R., Mojzsis, S.J.,

    doi:10.1126/science.1196874. Brasser, R., Mojzsis, S.J.,

  3. [12]

    Monthly Notices of the Royal Astronomical Society 304, 793–799

    A hybrid symplectic integrator that permits close encounters between massive bodies. Monthly Notices of the Royal Astronomical Society 304, 793–799. doi:10.1046/j.1365-8711.1999.02379.x. Chambers, J., Wetherill, G.,

  4. [20]

    Can a jumping-Jupiter trigger the Moon's formation impact?

    Can a jumping-Jupiter trigger the Moon’s formation impact? Monthly Notices of the Royal Astronomical Society 507, 539–547. doi:10.1093/mnras/stab2188, arXiv:2107.04181. Drążkowska,J.,Alibert,Y.,2017.Planetesimalformationstartsatthesnowline.AstronomyandAstrophysics608,A92.doi: 10.1051/0004-6361/ 201731491, arXiv:1710.00009. Drążkowska, J., Alibert, Y., Moore, B.,

  5. [21]

    Astronomy & Astrophysics 594, A105

    Close-in planetesimal formation by pile-up of drifting pebbles. Astronomy & Astrophysics 594, A105. doi:10.1051/0004-6361/201628983, arXiv:1607.05734. Drążkowska, J., Dullemond, C.P.,

  6. [22]

    Planetesimal formation during protoplanetary disk buildup

    Planetesimal formation during protoplanetary disk buildup. Astronomy & Astrophysics 614, A62. doi:10.1051/0004-6361/201732221, arXiv:1803.00575. Edwards, G.H., Keller, C.B., Newton, E.R., Stewart, C.W.,

  7. [23]

    An early giant planet instability recorded in asteroidal meteorites

    An early giant planet instability recorded in asteroidal meteorites. Nature Astronomy 8, 1264–1276. doi:10.1038/s41550-024-02340-6, arXiv:2309.10906. Fischer, R.A., Ciesla, F.J.,

  8. [24]

    Dry Late Accretion inferred from Venus' coupled atmosphere and internal evolution

    Dynamics of the terrestrial planets from a large number of N-body simulations. Earth and Planetary Science Letters 392, 28–38. doi:10.1016/j.epsl.2014.02.011. Fischer,R.A.,Nimmo,F.,2018.Effectsofcoreformationonthehf-wisotopiccompositionoftheearthanddatingofthemoon-formingimpact.Earth and Planetary Science Letters 499, 257–265. URL:https://www.sciencedirec...

Show all 67 references
  1. [27]

    The Astrophysical Journal 703, 1131–1140

    Formation of the Terrestrial Planets from a Narrow Annulus. The Astrophysical Journal 703, 1131–1140. doi:10.1088/ 0004-637X/703/1/1131, arXiv:0908.0743. Hunt,A.C.,Theis,K.J.,Rehkämper,M.,Benedix,G.K.,Andreasen,R.,Schönbächler,M.,2022. Thedissipationofthesolarnebulaconstrained...

  2. [29]

    Nature 508, 84–87

    Highly siderophile elements in earth’s mantle as a clock for the moon-forming impact. Nature 508, 84–87. URL:https://doi.org/10.1038/nature13172, doi:10.1038/nature13172. Johansen, A., Blum, J., Tanaka, H., Ormel, C., Bizzarro, M., Rickman, H.,

  3. [30]

    (Eds.), Protostars and Planets VI, pp

    The Multifaceted Planetesimal Formation Process, in: Beuther, H., Klessen, R.S., Dullemond, C.P., Henning, T. (Eds.), Protostars and Planets VI, pp. 547–570. doi:10.2458/azu_uapress_ 9780816531240-ch024, arXiv:1402.1344. Joiret,S.,Raymond,S.N.,Avice,G.,Clement,M.S.,2024.Crashc...

  4. [31]

    Icarus 252, 161–174

    The feeding zones of terrestrial planets and insights into moon formation. Icarus 252, 161–174. URL: http://dx.doi.org/10.1016/j.icarus.2015.01.013, doi:10.1016/j.icarus.2015.01.013. Kleine, T., Steller, T., Burkhardt, C., Nimmo, F.,

  5. [33]

    Geochimica et Cosmochimica Acta 73, 5150–5188

    Hf-W chronology of the accretion and early evolution of asteroids and terrestrial planets. Geochimica et Cosmochimica Acta 73, 5150–5188. doi:10.1016/j.gca. 2008.11.047. Kokubo, E., Ida, S.,

  6. [34]

    Icarus 131, 171–178

    Oligarchic growth of protoplanets. Icarus 131, 171–178. URL:https://www.sciencedirect.com/science/ article/pii/S0019103597958401, doi:https://doi.org/10.1006/icar.1997.5840. Kokubo,E.,Ida,S.,2000. FormationofProtoplanetsfromPlanetesimalsintheSolarNebula. Icarus143,15–27. doi: ...

  7. [35]

    ProceedingsoftheNationalAcademyofSciences114,6712–6716

    Age of jupiter inferred from the distinct genetics and formation times of meteorites. ProceedingsoftheNationalAcademyofSciences114,6712–6716. URL: https://www.pnas.org/doi/abs/10.1073/pnas.1704461114, doi:https://doi.org/10.1073/pnas.1704461114, arXiv:https://www.pnas.org/doi/...

  8. [37]

    Planetesimals to Protoplanets. I. Effect of Fragmentation on Terrestrial Planet Formation. The Astrophysical Journal 625, 427–440. doi:10.1086/429402. Levison, H.F., Morbidelli, A., Tsiganis, K., Nesvorný, D., Gomes, R.,

  9. [39]

    Science 379, 369–372

    Nucleosynthetic isotope anomalies of zinc in meteorites constrain the origin of Earth’s volatiles. Science 379, 369–372. doi:10.1126/science.abn1021. Mojzsis, S.J., Brasser, R., Kelly, N.M., Abramov, O., Werner, S.C., 2019a. Onset of Giant Planet Migration before 4480 Million ...

  10. [41]

    Morbidelli, A., Baillié, K., Batygin, K., Charnoz, S., Guillot, T., Rubie, D.C., Kleine, T.,

    doi:10.3847/1538-4357/ab2c03, arXiv:1903.08825. Morbidelli, A., Baillié, K., Batygin, K., Charnoz, S., Guillot, T., Rubie, D.C., Kleine, T.,

  11. [43]

    Annual Review of Earth and Planetary Sciences 40, 251–275

    Building Terrestrial Planets. Annual Review of Earth and Planetary Sciences 40, 251–275. doi:10.1146/annurev-earth-042711-105319, arXiv:1208.4694. Morbidelli,A.,Nesvorny,D.,Laurenz,V.,Marchi,S.,Rubie,D.C.,Elkins-Tanton,L.,Wieczorek,M.,Jacobson,S.,2018. Thetimelineofthelunar bo...

  12. [45]

    Earth and Planetary Science Letters 626, 118521

    Isotopic trichotomy of main belt asteroids from implantation of outer solar system planetesimals. Earth and Planetary Science Letters 626, 118521. doi:10.1016/j.epsl.2023.118521, arXiv:2311.16053. Nesvorný,D.,Vokrouhlický,D.,Bottke,W.F.,Levison,H.F.,2018. Evidenceforveryearlym...

  13. [46]

    Annual Review of Astronomy and Astrophysics 56, 137–174

    Dynamical evolution of the early solar system. Annual Review of Astronomy and Astrophysics 56, 137–174. URL: http://dx.doi.org/10.1146/annurev-astro-081817-052028, doi:10.1146/annurev-astro-081817-052028. Nesvorný,D.,Roig,F.V.,Deienno,R.,2021. Theroleofearlygiant-planetinstabi...

  14. [49]

    grand tack

    Water delivery and giant impacts in the "grand tack" scenario. Icarus 239, 74–84. URL: https://www.sciencedirect.com/science/article/pii/S0019103514002620, doi:https://doi.org/ 10.1016/j.icarus.2014.05.009. Ormel, C.W., Klahr, H.H.,

  15. [50]

    Nimmo,F.,Kleine,T.,Morbidelli,A.,2024a

    URL: https://dx.doi.org/10.3847/1538-3881/abc8ef, doi:10.3847/1538-3881/abc8ef. Nimmo,F.,Kleine,T.,Morbidelli,A.,2024a. Tidallydrivenremeltingaround4.35billionyearsagoindicatestheMoonisold. Nature636,598–602. doi:10.1038/s41586-024-08231-0. Nimmo, F., Kleine, T., Morbidelli, A...

  16. [52]

    Astronomy and Astrophysics 623, A169

    Consequences of planetary migration on the minor bodies of the early solar system. Astronomy and Astrophysics 623, A169. doi:10.1051/0004-6361/201833713, arXiv:1902.04591. Rauch, K.P., Holman, M.,

  17. [53]

    The Astronomical Journal 117, 1087–1102

    Dynamical Chaos in the Wisdom-Holman Integrator: Origins and Solutions. The Astronomical Journal 117, 1087–1102. doi:10.1086/300720, arXiv:astro-ph/9803340. Raymond, S.N., Izidoro, A.,

  18. [54]

    Science Advances 3, e1701138

    The empty primordial asteroid belt. Science Advances 3, e1701138. URL: https://www.science.org/doi/abs/10.1126/sciadv.1701138, doi: 10.1126/sciadv.1701138, arXiv:https://www.science.org/doi/pdf/10.1126/sciadv.1701138. Raymond, S.N., Izidoro, A., 2017a. Origin of water in the i...

  19. [55]

    Uni- versity of Arizona Press

    Terrestrial Planet Formation at Home and Abroad. Uni- versity of Arizona Press. URL: http://dx.doi.org/10.2458/azu_uapress_9780816531240-ch026, doi:10.2458/azu_uapress_ 9780816531240-ch026. Duarte Branco et al.:Preprint submitted to Elsevier Page 19 of 20 Raymond, S.N., Morbid...

  20. [56]

    (Eds.), Demographics of Exoplanetary Systems, Lecture Notes of the 3rd Advanced School on Exoplanetary Science, pp

    Planet Formation: Key Mechanisms and Global Models, in: Biazzo, K., Bozza, V., Mancini, L., Sozzetti, A. (Eds.), Demographics of Exoplanetary Systems, Lecture Notes of the 3rd Advanced School on Exoplanetary Science, pp. 3–82. doi:10.1007/ 978-3-030-88124-5_1 , arXiv:2002.0575...

  21. [57]

    Icarus 203, 644–662

    Building the terrestrial planets: Constrained accretion in the inner Solar System. Icarus 203, 644–662. doi:10.1016/j.icarus.2009.05.016, arXiv:0905.3750. Raymond,S.N.,Quinn,T.,Lunine,J.I.,2005. Terrestrialplanetformationindiskswithvaryingsurfacedensityprofiles. TheAstrophysic...

  22. [58]

    Terrestrial accretion and dynamics

    High-resolution simulations of the final assembly of Earth-like planets I. Terrestrial accretion and dynamics. Icarus 183, 265–282. doi:10.1016/j.icarus.2006.03.011, arXiv:astro-ph/0510284. Raymond, S.N., Schlichting, H.E., Hersant, F., Selsis, F.,

  23. [60]

    Icarus 248, 89–108

    Accretion and differentiation of the terrestrial planets with implications for the compositions of early-formed Solar System bodies and accretion of water. Icarus 248, 89–108. doi:10.1016/j.icarus.2014.10.015, arXiv:1410.3509. Savage,P.S.,Moynier,F.,Boyet,M.,2022. Zincisotopea...

  24. [61]

    Icarus 339, 113605

    Dynamical evidence for an early giant planet instability. Icarus 339, 113605. URL: https://www.sciencedirect.com/science/article/pii/S0019103519301332, doi:https: //doi.org/10.1016/j.icarus.2019.113605. Steller,T.,Burkhardt,C.,Yang,C.,Kleine,T.,2022. Nucleosyntheticzincisotope...

  25. [63]

    Chemie der Erde / Geochemistry 69, 101–125

    Highly siderophile elements in the Earth, Moon and Mars: Update and implications for planetary accretion and differentiation. Chemie der Erde / Geochemistry 69, 101–125. doi:10.1016/j.chemer.2008.10.001. Walsh, K.J., Morbidelli, A., Raymond, S.N., O’Brien, D.P., Mandell, A.M.,

  26. [65]

    Earth and Planetary Science Letters 311, 93–100

    Stable-isotopic anomalies and the accretionary assemblage of the earth and mars: A subordinate role for carbonaceous chondrites. Earth and Planetary Science Letters 311, 93–100. URL: https://www.sciencedirect.com/science/article/pii/ S0012821X11005115, doi:https://doi.org/10.1...

  27. [67]

    Icarus 396, 115497

    Terrestrial planet formation from a ring. Icarus 396, 115497. URL: http://dx.doi.org/10.1016/j.icarus.2023.115497, doi:10.1016/j.icarus.2023.115497. Worsham, E.A., Kleine, T.,

  28. [68]

    Science Advances 7, eabh2837

    Late accretionary history of Earth and Moon preserved in lunar impactites. Science Advances 7, eabh2837. doi:10.1126/sciadv.abh2837. Zhu, M.H., Morbidelli, A., Neumann, W., Yin, Q.Z., Day, J.M.D., Rubie, D.C., Archer, G.J., Artemieva, N., Becker, H., Wünnemann, K.,

  29. [69]

    Nature Astronomy 5, 1286–1296

    Common feedstocks of late accretion for the terrestrial planets. Nature Astronomy 5, 1286–1296. doi:10.1038/s41550-021-01475-0. Duarte Branco et al.:Preprint submitted to Elsevier Page 20 of 20

  30. [152]

    Lichtenberg,T.,Drążkowska,J.,Schönbächler,M.,Golabek,G.J.,Hands,T.O.,2021

    doi:10.1088/0004-6256/142/5/152. Lichtenberg,T.,Drążkowska,J.,Schönbächler,M.,Golabek,G.J.,Hands,T.O.,2021. BifurcationofplanetarybuildingblocksduringSolarSystem formation. Science 371, 365–370. doi:10.1126/science.abb3091, arXiv:2101.08571. Liu,B.,Raymond,S.N.,Jacobson,S.A.,2...

  31. [217]

    DeSouza, S.R., Roig, F., Nesvorný, D.,

    doi:10.1126/science.1133355. DeSouza, S.R., Roig, F., Nesvorný, D.,

  32. [1052]

    Canup, R.M., Asphaug, E., 2001a

    doi:10.1126/science.1226073. Canup, R.M., Asphaug, E., 2001a. Origin of the Moon in a giant impact near the end of the Earth’s formation. Nature 412, 708–712. doi:10.1038/35089010. Canup, R.M., Asphaug, E., 2001b. Origin of the Moon in a giant impact near the end of the Earth’...

  33. [1990]

    Annual Review of Earth and Planetary Sciences 18, 205–256

    Formation of the earth. Annual Review of Earth and Planetary Sciences 18, 205–256. doi:10.1146/annurev.ea.18. 050190.001225. Wetherill,G.W.,Stewart,G.R.,1993. FormationofPlanetaryEmbryos:EffectsofFragmentation,LowRelativeVelocity,andIndependentVariation of Eccentricity and Inc...

  34. [1996]

    Icarus 119, 261–268

    The Stability of Multi-Planet Systems. Icarus 119, 261–268. doi:10.1006/icar.1996.0019. Clement, M.S., Kaib, N.A., Raymond, S.N., Walsh, K.J.,

  35. [1998]

    Icarus 136, 304–327

    Making the terrestrial planets: N-body integrations of planetary embryos in three dimensions. Icarus 136, 304–327. URL: https://www.sciencedirect.com/science/article/pii/S0019103598960079, doi:https://doi.org/10.1006/ icar.1998.6007. Chambers, J.E.,

  36. [1999]

    Icarus 142, 219–237

    On the Character and Consequences of Large Impacts in the Late Stage of Terrestrial Planet Formation. Icarus 142, 219–237. doi:10.1006/icar.1999.6201. Armitage, P.J., Eisner, J.A., Simon, J.B.,

  37. [2001]

    Icarus 152, 205–224

    Making More Terrestrial Planets. Icarus 152, 205–224. doi:10.1006/icar.2001.6639. Chambers, J.E., Wetherill, G.W., Boss, A.P.,

  38. [2003]

    Icarus 161, 431–455

    Oligarchic growth of giant planets. Icarus 161, 431–455. doi:10.1016/S0019-1035(02) 00043-X, arXiv:astro-ph/0303269. Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F.,

  39. [2005]

    Nature 435, 466–469

    Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets. Nature 435, 466–469. doi:10.1038/nature03676. Hansen, B.M.S.,

  40. [2006]

    Icarus 184, 39–58

    Terrestrial planet formation with strong dynamical friction. Icarus 184, 39–58. doi:10.1016/ j.icarus.2006.04.005. O’Brien, D.P., Walsh, K.J., Morbidelli, A., Raymond, S.N., Mandell, A.M.,

  41. [2007]

    The Astronomical Journal 134, 1790–1798

    Dynamics of the Giant Planets of the Solar System in the Gaseous Protoplanetary Disk and Their Relationship to the Current Orbital Architecture. The Astronomical Journal 134, 1790–1798. doi:10.1086/ 521705, arXiv:0706.1713. Morbidelli, A., Wood, B.J., 2015a. Late Accretion and...

  42. [2008]

    Astronomy and Astrophysics 482, 333–340

    Constraints on resonant-trapping for two planets embedded in a protoplanetary disc. Astronomy and Astrophysics 482, 333–340. doi:10.1051/0004-6361:20079062, arXiv:0802.2033. Pirani, S., Johansen, A., Bitsch, B., Mustill, A.J., Turrini, D.,

  43. [2009]

    The Astrophysical Journal 703, 1131–1140

    Formation of the terrestrial planets from a narrow annulus. The Astrophysical Journal 703, 1131–1140. URL: http://dx.doi.org/10.1088/0004-637X/703/1/1131, doi:10.1088/0004-637x/703/1/1131. Hansen, B.M.S.,

  44. [2010]

    Analytical expressions for the accretion of small bodies in laminar disks

    The effect of gas drag on the growth of protoplanets. Analytical expressions for the accretion of small bodies in laminar disks. Astronomy and Astrophysics 520, A43. doi:10.1051/0004-6361/201014903, arXiv:1007.0916. Pierens, A., Nelson, R.P.,

  45. [2011]

    Nature 475, 206–209

    A low mass for Mars from Jupiter’s early gas-driven migration. Nature 475, 206–209. doi:10.1038/nature10201, arXiv:1201.5177. Warren, P.H.,

  46. [2012]

    Astronomy & Astrophysics 544, A32

    Rapid growth of gas-giant cores by pebble accretion. Astronomy & Astrophysics 544, A32. doi:10.1051/ 0004-6361/201219127, arXiv:1205.3030. Duarte Branco et al.:Preprint submitted to Elsevier Page 18 of 20 Laskar, J.,

  47. [2013]

    Icarus 226, 671–681

    Dynamical and collisional constraints on a stochastic late veneer on the terrestrial planets. Icarus 226, 671–681. doi:10.1016/j.icarus.2013.06.019, arXiv:1306.4325. Rubie, D.C., Jacobson, S.A., Morbidelli, A., O’Brien, D.P., Young, E.D., de Vries, J., Nimmo, F., Palme, H., Fr...

  48. [2014]

    Philosophical Transactions of the Royal Society of London Series A 372, 20130260–20130260

    The iodine-plutonium-xenon age of the Moon-Earth system revisited. Philosophical Transactions of the Royal Society of London Series A 372, 20130260–20130260. doi:10.1098/rsta.2013.0260, arXiv:1511.00952. Benz, W., Slattery, W.L., Cameron, A.G.W.,

  49. [2015]

    Monthly Notices of the Royal Astronomical Society 453, 3619–3634

    Terrestrial planet formation constrained by Mars and the structure of the asteroid belt. Monthly Notices of the Royal Astronomical Society 453, 3619–3634. doi:10.1093/mnras/stv1835, arXiv:1508.01365. Jacobson, S.A., Morbidelli, A., Raymond, S.N., O’Brien, D.P., Walsh, K.J., Ru...

  50. [2016]

    The Astrophysical Journal Letters 828, L2

    Prompt Planetesimal Formation beyond the Snow Line. The Astrophysical Journal Letters 828, L2. doi:10.3847/2041-8205/828/1/L2, arXiv:1608.03592. Avice, G., Marty, B.,

  51. [2017]

    Nature 541, 521–524

    The isotopic nature of the Earth’s accreting material through time. Nature 541, 521–524. doi:10.1038/nature20830. Duarte Branco et al.:Preprint submitted to Elsevier Page 17 of 20 Dauphas, N., Hopp, T., Nesvorný, D.,

  52. [2018]

    Icarus 311, 340–356

    Mars’ growth stunted by an early giant planet instability. Icarus 311, 340–356. doi:10.1016/j.icarus.2018.04.008, arXiv:1804.04233. Ćuk,M.,Stewart,S.T.,2012. MakingtheMoonfromaFast-SpinningEarth:AGiantImpactFollowedbyResonantDespinning. Science338,1047. doi:10.1126/science.122...

  53. [2019]

    Nature Astronomy 3, 736–741

    Molybdenum isotopic evidence for the late accretion of outer solar system material to earth. Nature Astronomy 3, 736–741. URL:https://doi.org/10.1038/s41550-019-0779-y, doi:10.1038/s41550-019-0779-y. Canup, Robin M. Righter, K., Dauphas, N., Pahlevan, K., Ćuk, M., Lock, S.J., ...

  54. [2020]

    Nature Astronomy 4, 492–499

    The partitioning of the inner and outer Solar System by a structured protoplanetary disk. Nature Astronomy 4, 492–499. doi:10.1038/s41550-019-0978-6. Budde, G., Burkhardt, C., Kleine, T.,

  55. [2021]

    arXiv e-printsarXiv:2103.02045

    Origin of the Moon. arXiv e-printsarXiv:2103.02045. Canup, R.M.,

  56. [2022]

    Nature Astronomy 6, 72–79

    Contemporary formation of early Solar System planetesimals at two distinct radial locations. Nature Astronomy 6, 72–79. doi:10.1038/s41550-021-01517-7, arXiv:2112.15413. Morbidelli, A., Lunine, J.I., O’Brien, D.P., Raymond, S.N., Walsh, K.J.,

  57. [2023]

    Icarus 397, 115519.URL: https://www.sciencedirect.com/science/article/pii/S0019103523000969,doi: https://doi.org/10.1016/j

    An inner solar system origin of volatile elements in mars. Icarus 397, 115519.URL: https://www.sciencedirect.com/science/article/pii/S0019103523000969,doi: https://doi.org/10.1016/j. icarus.2023.115519. Kleine, T., Touboul, M., Bourdon, B., Nimmo, F., Mezger, K., Palme, H., Ja...

  58. [2024]

    Icarus 408, 115805

    Bayesian inference on the isotopic building blocks of Mars and Earth. Icarus 408, 115805. doi:10.1016/j.icarus.2023.115805, arXiv:2309.15290. Day,J.M.D.,Pearson,D.G.,Taylor,L.A.,2007.HighlySiderophileElementConstraintsonAccretionandDifferentiationoftheEarth-MoonSystem. Science 315,

  59. [2025]

    Geochimica et Cosmochimica Acta 392, 38–51

    The non-carbonaceous nature of Earth’s late-stage accretion. Geochimica et Cosmochimica Acta 392, 38–51. doi:10.1016/j.gca.2024.11.005. Birnstiel, T., Fang, M., Johansen, A.,

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.