Simulations of a late lunar-forming impact

Canup, R. M.

doi:10.1016/j.icarus.2003.09.028

Cited by 605 publications

(652 citation statements)

References 29 publications

Supporting

Mentioning

625

Contrasting

Unclassified

Order By: Relevance

“…This distribution is shown in Figure 17, where we plot the parameter γ, which is the ratio of Theia's mass to the combined mass of Theia and the proto-Earth at the time of impact. To mix the Earth and Moon evenly enough, Canup (2012) finds that Theia must have had γ 0.4. In Figure 17, we see that such collisions are not found in any of our simulations.…”

Section: Potential Solutions: Massive Theias and Highmentioning

confidence: 99%

The feeding zones of terrestrial planets and insights into Moon formation

Kaib

Cowan

2015

Icarus

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

Section: Potential Solutions: Massive Theias and Highmentioning

confidence: 99%

The feeding zones of terrestrial planets and insights into Moon formation

Kaib

Cowan

2015

Icarus

105

View full text Add to dashboard Cite

show abstract

“…Cameron and Ward 1976;Canup 2004a). Continued work on the giant impact hypothesis eventually resulted in what has become known as the Canonical model (e.g.…”

Section: Earth-moon Systemmentioning

confidence: 99%

Insights into Planet Formation from Debris Disks

Wyatt

Jackson

2016

Space Sci Rev

View full text Add to dashboard Cite

Giant impacts refer to collisions between two objects each of which is massive enough to be considered at least a planetary embryo. The putative collision suffered by the proto-Earth that created the Moon is a prime example, though most Solar System bodies bear signatures of such collisions. Current planet formation models predict that an epoch of giant impacts may be inevitable, and observations of debris around other stars are providing mounting evidence that giant impacts feature in the evolution of many planetary systems. This chapter reviews giant impacts, focussing on what we can learn about planet formation by studying debris around other stars. Giant impact debris evolves through mutual collisions and dynamical interactions with planets. General aspects of this evolution are outlined, noting the importance of the collision-point geometry. The detectability of the debris is discussed using the example of the Moon-forming impact. Such debris could be detectable around another star up to 10 Myr post-impact, but model uncertainties could reduce detectability to a few 100 yr window. Nevertheless the 3 % of young stars with debris at levels expected during terrestrial planet formation provide valuable constraints on formation models; implications for super-Earth formation are also discussed. Variability recently observed in some bright disks promises to illuminate the evolution during the earliest phases when vapour condensates may be optically thick and acutely affected by the collision-point geometry. The outer reaches of planetary systems may also exhibit signatures of giant impacts, such as the clumpy debris structures seen around some stars.

show abstract

“…Collisions designed to re-create the observed properties of the Earth/Moon system typically involve M T ∼ 1.05M E , and impact velocities comparable to the escape velocity of the system, v imp ∼ v esc,sys ∼ 10 km/s [16,83]. Large impact-generated disks can form in collisions with higher velocities, a few×v esc , but this phenomenon has been explored for only a limited range of impactor-to-target mass ratios, and impact angles [19,20].…”

Section: Impact Simulationsmentioning

confidence: 99%

“…A collision between two sizable rock/iron planetary bodies creates an orbiting disk of material that is composed of a two-phase silicate "foam" containing both liquid and vapor [16,79,91]. The mass of the final moon (or moons) created, and the time scale over which accretion takes place, is controlled by the evolution of the disk vapor [79][80][81][82].…”

Section: Accretion From a Liquid/vapor Diskmentioning

confidence: 99%

“…Earth's Moon and Charon are thought to have formed from planet-scale collisions [13][14][15][16][17]. Numerical simulations of the collisions and the subsequent accretion of impact-generated debris show that systems with the proper masses, angular momenta, and compositions of each system are consistent with a collision with a body 10% to 50% the mass of the precursor planet [16][17][18][19][20]. In the inner Solar System, collisions between planetary embryos are common during the late stages of terrestrial planet accretion [1,2,21].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Formation of exomoons: a solar system perspective

Barr

2016

Astronomical Review

View full text Add to dashboard Cite

Satellite formation is a natural by-product of planet formation. With the discovery of numerous extrasolar planets, it is likely that moons of extrasolar planets (exomoons) will soon be discovered. Some of the most promising techniques can yield both the mass and radius of the moon. Here, I review recent ideas about the formation of moons in our Solar System, and discuss the prospects of extrapolating these theories to predict the sizes of moons that may be discovered around extrasolar planets. It seems likely that planet-planet collisions could create satellites around rocky or icy planets which are large enough to be detected by currently available techniques. Detectable exomoons around gas giants may be able to form by co-accretion or capture, but determining the upper limit on likely moon masses at gas giant planets requires more detailed, modern simulations of these processes.

show abstract

Simulations of a late lunar-forming impact

Cited by 605 publications

References 29 publications

The feeding zones of terrestrial planets and insights into Moon formation

The feeding zones of terrestrial planets and insights into Moon formation

Insights into Planet Formation from Debris Disks

Formation of exomoons: a solar system perspective

Contact Info

Product

Resources

About