Building the terrestrial planets: Constrained accretion in the inner Solar System

Raymond, Sean N.; O’Brien, D. P.; Morbidelli, Alessandro; Kaib, Nathan A.

doi:10.1016/j.icarus.2009.05.016

Cited by 413 publications

(644 citation statements)

References 143 publications

(268 reference statements)

Supporting

Mentioning

594

Contrasting

Unclassified

Order By: Relevance

“…However, matching the exoplanet orbital distribution requires a contribution of up to ∼30-40% of stable systems (Juric & Tremaine 2008;Zakamska et al 2011), which invariably form systems with two or more terrestrial planets. The orbits of surviving giant planets act as a measure of the strength of the instability, and as expected (Levison & Agnor 2003;Raymond et al 2009) terrestrial planet formation is far less efficient for eccentric giant planets.…”

Section: Resultssupporting

confidence: 54%

The debris disk – terrestrial planet connection

et al. 2010

Self Cite

View full text Add to dashboard Cite

Abstract. The eccentric orbits of the known extrasolar giant planets provide evidence that most planet-forming environments undergo violent dynamical instabilities. Here, we numerically simulate the impact of giant planet instabilities on planetary systems as a whole. We find that populations of inner rocky and outer icy bodies are both shaped by the giant planet dynamics and are naturally correlated. Strong instabilities -those with very eccentric surviving giant planets -completely clear out their inner and outer regions. In contrast, systems with stable or low-mass giant planets form terrestrial planets in their inner regions and outer icy bodies produce dust that is observable as debris disks at mid-infrared wavelengths. Fifteen to twenty percent of old stars are observed to have bright debris disks (at λ ∼ 70µm) and we predict that these signpost dynamically calm environments that should contain terrestrial planets.

show abstract

Section: Resultssupporting

confidence: 54%

The debris disk – terrestrial planet connection

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, the late stages of terrestrial planet formation are not a local process. Numerical studies of the final giant impact phase of terrestrial planet formation have conclusively demonstrated that the feeding zones of terrestrial planets are quite large and that most bodies undergo substantial and stochastic radial migration (Chambers 2001;Raymond et al 2004Raymond et al , 2005O'Brien et al 2006;Raymond et al 2006Raymond et al , 2009Fischer & Ciesla 2014). As a result, there is no reason to expect that Earth and its final impactor formed from the same zones of the protoplanetary disk.…”

Section: Theia and The Moon-forming Impactmentioning

confidence: 99%

The feeding zones of terrestrial planets and insights into Moon formation

Kaib

Cowan

2015

Icarus

Self Cite

105

View full text Add to dashboard Cite

The final stage of terrestrial planet formation consists of several hundred approximately lunar mass bodies accreting into a few terrestrial planets. This final stage is stochastic, making it hard to predict which parts of the original planetesimal disk contributed to each of our terrestrial planets. Here we present an extensive suite of terrestrial planet formation simulations that allows quantitative analysis of this process. Although there is a general correlation between a planet's location and the initial semi-major axes of its constituent planetesimals, we concur with previous studies that Venus, Earth, and Mars analogs have overlapping, stochastic feeding zones. We quantify the feeding zone width, ∆a, as the mass-weighted standard deviation of the initial semi-major axes of the planetary embryos and planetesimals that make up the final planet. The size of a planet's feeding zone in our simulations does not correlate with its final mass or semi-major axis, suggesting there is no systematic trend between a planet's mass and its volatile inventory. Instead, we find that the feeding zone of any planet more massive than 0.1M ⊕ is roughly proportional to the radial extent of the initial disk from which it formed: ∆a ≈ 0.25(a max − a min ), where a min and a max are the inner and outer edge of the initial planetesimal disk. These wide stochastic feeding zones have significant consequences for the origin of the Moon, since the canonical scenario predicts the Moon should be primarily composed of material from Earth's last major impactor (Theia), yet its isotopic composition is indistinguishable from Earth. In particular, we find that the feeding zones of Theia analogs are significantly more stochastic than the planetary analogs. Depending on our assumed initial distribution of oxygen isotopes within the planetesimal disk, we find a ∼5% or less probability that the Earth and Theia will form with an isotopic difference equal to or smaller than the Earth and Moon's. In fact we predict that every planetary mass body should be expected to have a unique isotopic signature. In addition, we find paucities of massive Theia analogs and high velocity moon-forming collisions, two recently proposed explanations for the Moon's isotopic composition. Our work suggests that there is still no scenario for the Moon's origin that explains its isotopic composition with a high probability event.

show abstract

“…Here, the authors claim to have found a possible solution to the persistent "small Mars" problem (e.g. Raymond et al 2009) by reversing the mass-order of planetary embryos: more massive embryos can form further in because accretion is more efficient. Although encouraging, it must be emphasized that these N-body models contain a great number of free parametersranging from the initial size-distribution of planetesimals, their location in the disk, to the properties of the pebbles and the gas-which means a proper investigation would imply a (prohibitively?)…”

Section: Solar Systemmentioning

confidence: 99%

The Emerging Paradigm of Pebble Accretion

Ormel

2017

Astrophysics and Space Science Library

108

View full text Add to dashboard Cite

Pebble accretion is the mechanism in which small particles ("pebbles") accrete onto big bodies (planetesimals or planetary embryos) in gas-rich environments. In pebble accretion, accretion occurs by settling and depends only on the mass of the gravitating body, not its radius. I give the conditions under which pebble accretion operates and show that the collisional cross section can become much larger than in the gas-free, ballistic, limit. In particular, pebble accretion requires the pre-existence of a massive planetesimal seed. When pebbles experience strong orbital decay by drift motions or are stirred by turbulence, the accretion efficiency is low and a great number of pebbles are needed to form Earth-mass cores. Pebble accretion is in many ways a more natural and versatile process than the classical, planetesimal-driven paradigm, opening up avenues to understand planet formation in solar and exoplanetary systems.

show abstract

Building the terrestrial planets: Constrained accretion in the inner Solar System

Abstract: Icarus, 203, pp. 644-662 (2009)International audienc

Cited by 413 publications

References 143 publications

The debris disk – terrestrial planet connection

The debris disk – terrestrial planet connection

The feeding zones of terrestrial planets and insights into Moon formation

The Emerging Paradigm of Pebble Accretion

Contact Info

Product

Resources

About