Can planetesimals left over from terrestrial planet formation produce the lunar Late Heavy Bombardment?

Bottke, W. F.; Levison, Harold F.; Nesvorný, David; Dones, L.

doi:10.1016/j.icarus.2007.02.010

Cited by 124 publications

(104 citation statements)

References 106 publications

(225 reference statements)

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“…We warn against this superficial position. It seems to us that there are at least four strong pieces of evidence in favour of the cataclysmic spike of the LHB: (i) basins on the Moon as big as Imbrium and Orientale could not have formed as late as 3.8 Gyr ago if the bombardment rate had been declining monotonically since the time of planet formation at the rate indicated by dynamical models without giant planet migration (Bottke et al 2007); (ii) old zircons on Earth demonstrate that the climate on Earth 4.3−3.9 Gyr ago was relatively cool (i.e. the impact rate was low; Mojzsis et al 2001), and that strong heating events, probably associated with impacts, happened approximately 3.8 Gyr ago (Trail et al 2007); (iii) the most prominent impact basins on Mars occurred after the disappearance of Martian magnetic field (Lillis et al 2006(Lillis et al , 2007; (iv) impact basins on Iapetus occurred after the formation of its equatorial ridge, which is estimated to have formed between t = 200−800 Myr (Castillo-Rogez et al 2007).…”

Section: Discussionmentioning

confidence: 99%

Constructing the secular architecture of the solar system II: the terrestrial planets

Brasser¹,

Morbidelli²,

Gomes

et al. 2009

A&A

149

185

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We investigate the dynamical evolution of the terrestrial planets during the planetesimal-driven migration of the giant planets. A basic assumption of this work is that giant planet migration occurred after the completion of terrestrial planet formation, such as in the models that link the former to the origin of the late heavy bombardment. The divergent migration of Jupiter and Saturn causes the g 5 eigenfrequency to cross resonances of the form g 5 = g k with k ranging from 1 to 4. Consequently these secular resonances cause large-amplitude responses in the eccentricities of the terrestrial planets if the amplitude of the g 5 mode in Jupiter is similar to the current one. We show that the resonances g 5 = g 4 and g 5 = g 3 do not pose a problem if Jupiter and Saturn have a fast approach and departure from their mutual 2:1 mean motion resonance. On the other hand, the resonance crossings g 5 = g 2 and g 5 = g 1 are more of a concern: they tend to yield a terrestrial system incompatible with the current one, with amplitudes of the g 1 and g 2 modes that are too large. We offer two solutions to this problem. The first solution states that a secular resonance crossing can also damp the amplitude of a Fourier mode if the latter is large originally. We show that the probability of the g 5 = g 2 resonance damping a primordially excited g 2 mode in the Earth and Venus is approximately 8%. Using the same mechanism to also ensure that the g 5 = g 1 resonance keeps the amplitude of the g 1 mode in Mercury within 0.4 reduces the overall probability to approximately 5%. However, these numbers may change for different initial excitations and migration speeds of the giant planets. A second scenario involves a "jumping Jupiter" in which encounters between an ice giant and Jupiter, without ejection of the former, cause the latter to migrate away from Saturn much faster than if migration is driven solely by encounters with planetesimals. In this case, the g 5 = g 2 and g 5 = g 1 resonances can be jumped over, or occur very briefly. We show that, in this case, the terrestrial system can have dynamical properties comparable to what is exhibited today. In the framework of the Nice model, we estimate that the probability that Jupiter had this kind of evolution is approximately 6%.

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Section: Discussionmentioning

confidence: 99%

Constructing the secular architecture of the solar system II: the terrestrial planets

Brasser¹,

Morbidelli²,

Gomes

et al. 2009

A&A

149

185

View full text Add to dashboard Cite

show abstract

“…The formation of the latest basins on the Moon (Imbrium and Orientale, and possibly all Nectarian basins) requires that new projectiles appeared in the terrestrial planet-crossing region several 100 My after terrestrial planet formation (Bottke et al 2007). The late instability of the giant planets would do this in a natural way Morbidelli et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Comets as collisional fragments of a primordial planetesimal disk

Morbidelli

Rickman

2015

A&A

120

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Context. The Rosetta mission and its exquisite measurements have revived the debate on whether comets are pristine planetesimals or collisionally evolved objects. Aims. We investigate the collisional evolution experienced by the precursors of current comet nuclei during the early stages of the solar system in the context of the so-called Nice model. Methods. We considered two environments for the collisional evolution: (1) the transplanetary planetesimal disk, from the time of gas removal until the disk was dispersed by the migration of the ice giants; and (2) the dispersing disk during the time that the scattered disk was formed. We performed simulations using different methods in the two cases to determine the number of destructive collisions typically experienced by a comet nucleus of 2 km radius. Results. In the widely accepted scenario, where the dispersal of the planetesimal disk occurred at the time of the Late Heavy Bombardment about 4 Gy ago, comet-sized planetesimals have a very low probability of surviving destructive collisions in the disk. On the extreme assumption that the disk was dispersed directly upon gas removal, a significant fraction of the planetesimals might have remained intact. However, these survivors would still bear the marks of many nondestructive impacts.Conclusions. The Nice model of solar system evolution predicts that typical km-sized comet nuclei are predominantly fragments resulting from collisions experienced by larger parent bodies. An important goal for future research is to investigate whether the observed properties of comet nuclei are compatible with such a collisional origin.

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“…It has been intensely debated whether these late basins are just the last big impacts that occurred during a bombardment declining in intensity since the time of the formation of the Moon (Hartmann 1975;Neukum & Ivanov 1996;Hartmann et al 2007), or if these basins formed during a sudden surge in the impact rate, called the late heavy bombardment (LHB; Tera et al 1974;Ryder 1990;Kring & Cohen 2002;Bottke et al 2007). Although there is still no unanimous consensus, most evidence now supports the latter hypothesis (see Hartmann et al 2000;and Chapman et al 2007 …”

Section: Introductionmentioning

confidence: 99%

The terrestrial Planet V hypothesis as the mechanism for the origin of the late heavy bombardment

Brasser

Morbidelli

2011

A&A

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In this study we attempt to model, with numerical simulations, the scenario for the origin of the late heavy bombardment (LHB) proposed in Chambers (2007, Icarus, 189, 386). Chambers suggested that the orbit of a fictitious sub-Mars sized embryo outside Mars became unstable and crossed a part of the asteroid belt until it was removed through ejection or collision. Chambers demonstrated that this kind of evolution can occur at the LHB time, but he did not check whether enough material could be liberated from the belt to be consistent with the magnitude of the LHB. We do that here. In addition to the asteroid belt, we also consider putative belts of small objects located between the orbits of the Earth and Venus (EV belt) or between the Earth and Mars (EM belt). We find that delivering enough material to the Moon from the asteroid belt requires at least a 5 lunar mass embryo crossing the entire asteroid belt up to 3.3 AU for longer than 300 Myr on a low-inclination orbit. We do not witness this to occur in over a hundred simulations. An alternative approach, which relies only on decimating the inner belt (<2.5 AU), requires that the inner belt originally contained 4 to 13 times more mass than the original outer belt. Regarding the putative asteroid belts in between the terrestrial planets, this scenario could be consistent with the LHB if EV belt contained a substantial population of small bodies, with the density of objects in orbital space larger than that of the current main asteroid belt, while the EM belt was as good as empty.

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Can planetesimals left over from terrestrial planet formation produce the lunar Late Heavy Bombardment?

Cited by 124 publications

References 106 publications

Constructing the secular architecture of the solar system II: the terrestrial planets

Constructing the secular architecture of the solar system II: the terrestrial planets

Comets as collisional fragments of a primordial planetesimal disk

The terrestrial Planet V hypothesis as the mechanism for the origin of the late heavy bombardment

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