Effects of Type I Migration on Terrestrial Planet Formation

McNeil, D. S.; Duncan, Martin J.; Levison, Harold F.

doi:10.1086/497687

Cited by 79 publications

(93 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It has been demonstrated by Kokubo & Genda (2010) that this a priori assumption of simple accretion does not significantly affect the results. The SyMBA code has already been used extensively in terrestrial planet formation simulations (Agnor et al 1999;Levison & Agnor 2003;O'Brien et al 2006;McNeil et al 2005). …”

Section: Methodsmentioning

confidence: 99%

The effect of an early planetesimal-driven migration of the giant planets on terrestrial planet formation

Walsh

Morbidelli

2011

A&A

View full text Add to dashboard Cite

The migration of the giant planets due to the scattering of planetesimals causes powerful resonances to move through the asteroid belt and the terrestrial planet region. Exactly when and how the giant planets migrated is not well known. In this paper we present results of an investigation of the formation of the terrestrial planets during and after the migration of the giant planets. The latter is assumed to have occurred immediately after the dissipation of the nebular disk -i.e. "early" with respect to the timing of the late heavy bombardment (LHB). The presumed cause of our modeled early migration of the giant planets is angular mometum transfer between the planets and scattered planetesimals. Our model forms the terrestrial planets from a disk of material which stretchs from 0.3-4.0 AU, evenly split in mass between planetesimals and planetary embryos. Jupiter and Saturn are initially at 5.4 and 8.7 AU respectively, on orbits with eccentricities comparable to the current ones, and migrate to 5.2 and 9.4 AU with an e-folding time of 5 Myr. Unfortunately, the terrestrial planets formed in the simulations are not good analogs for the current solar system, with Mars typically being much too massive. Moreover, the final distribution of the planetesimals remaining in the asteroid belt is inconsistent with the observed distribution of asteroids. This argues that, even if giant planet migration had occurred early, the real evolution of the giant planets would have to have been of the "jumping-Jupiter" type, i.e. the increase in orbital separation between Jupiter and Saturn had to be dominated by encounters between Jupiter and a third, Neptune-mass planet. This result was already demonstrated for late migrations occuring at the LHB time by previous work, and this paper shows those conclusions hold for early migration as well.

show abstract

Section: Methodsmentioning

confidence: 99%

The effect of an early planetesimal-driven migration of the giant planets on terrestrial planet formation

Walsh

Morbidelli

2011

A&A

View full text Add to dashboard Cite

show abstract

“…R04 suggests that the presence of other embryos might prevent gap opening. However, direct dynamical simulations of problems with similar dynamics have shown that this is not the case (McNeil et al 2005;. In particular, gaps are opened in situations where the embryos are well separated, while the particles become trapped in the L 4 and L 5 Lagrange points if the embryos are closely packed.…”

Section: A Not-so Brief Review Of Core Accretion Modelsmentioning

confidence: 99%

“…Although ambitious, Chambers (2008) used semianalytic methods to follow the evolution of the planetesimals, and thus did not fully account for processes such as gap opening, which has been shown to negatively effect accretion rates in the sheardominated regime (McNeil et al 2005;. He also did not include the effects of planetesimal-driven planet migration (Fernandez & Ip 1984;Hahn & Malhotra 1999;Gomes et al 2004;Kirsh et al 2009).…”

Section: A Not-so Brief Review Of Core Accretion Modelsmentioning

confidence: 99%

“…After all, there was a lot more gas than planetesimals in the original solar nebula. The first work of which we are aware that addresses this issue was McNeil et al (2005), which concentrated on the terrestrial planet region. 4 They found that, at least for the scenarios they investigated in this region of the solar system, planetesimal-driven migration does not counteract Type I migration.…”

Section: A Not-so Brief Review Of Core Accretion Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Modeling the Formation of Giant Planet Cores. I. Evaluating Key Processes

Levison¹,

Thommes²,

Duncan³

2010

The Astronomical Journal

Self Cite

157

164

View full text Add to dashboard Cite

One of the most challenging problems we face in our understanding of planet formation is how Jupiter and Saturn could have formed before the solar nebula dispersed. The most popular model of giant planet formation is the so-called core accretion model. In this model a large planetary embryo formed first, mainly by two-body accretion. This is then followed by a period of inflow of nebular gas directly onto the growing planet. The core accretion model has an Achilles heel, namely the very first step. We have undertaken the most comprehensive study of this process to date. In this study, we numerically integrate the orbits of a number of planetary embryos embedded in a swarm of planetesimals. In these experiments, we have included a large number of physical processes that might enhance accretion. In particular, we have included (1) aerodynamic gas drag, (2) collisional damping between planetesimals, (3) enhanced embryo cross sections due to their atmospheres, (4) planetesimal fragmentation, and (5) planetesimaldriven migration. We find that the gravitational interaction between the embryos and the planetesimals leads to the wholesale redistribution of material-regions are cleared of material and gaps open near the embryos. Indeed, in 90% of our simulations without fragmentation, the region near those embryos is cleared of planetesimals before much growth can occur. Thus, the widely used assumption that the surface density distribution of planetesimals is smooth can lead to misleading results. In the remaining 10% of our simulations, the embryos undergo a burst of outward migration that significantly increases growth. On timescales of ∼10 5 years, the outer embryo can migrate ∼6 AU and grow to roughly 30 M ⊕ . This represents a largely unexplored mode of core formation. We also find that the inclusion of planetesimal fragmentation tends to inhibit growth except for a narrow range of fragment migration rates.

show abstract

“…McNeil et al 2005). Type I decay is important for objects whose migration time scale t 1 is comparable to or shorter than the nebular lifetime t neb .…”

Section: (D ) Open Issuesmentioning

confidence: 99%

Accretion of the Earth

Canup

2008

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

The origin of the Earth and its Moon has been the focus of an enormous body of research. In this paper I review some of the current models of terrestrial planet accretion, and discuss assumptions common to most works that may require re-examination. Density-wave interactions between growing planets and the gas nebula may help to explain the current near-circular orbits of the Earth and Venus, and may result in large-scale radial migration of proto-planetary embryos. Migration would weaken the link between the present locations of the planets and the original provenance of the material that formed them. Fragmentation can potentially lead to faster accretion and could also damp final planet orbital eccentricities. The Moon-forming impact is believed to be the final major event in the Earth's accretion. Successful simulations of lunar-forming impacts involve a differentiated impactor containing between 0.1 and 0.2 Earth masses, an impact angle near 458 and an impact speed within 10 per cent of the Earth's escape velocity. All successful impacts-with or without pre-impact rotation-imply that the Moon formed primarily from material originating from the impactor rather than from the proto-Earth. This must ultimately be reconciled with compositional similarities between the Earth and the Moon.

show abstract

Effects of Type I Migration on Terrestrial Planet Formation

Cited by 79 publications

References 40 publications

The effect of an early planetesimal-driven migration of the giant planets on terrestrial planet formation

The effect of an early planetesimal-driven migration of the giant planets on terrestrial planet formation

Modeling the Formation of Giant Planet Cores. I. Evaluating Key Processes

Accretion of the Earth

Contact Info

Product

Resources

About