Giant Impact Research Articles

An Integrated Review of Pluto-Charon Binary Syatem

The Pluto-Charon binary system is a significant celestial configuration in the Kuiper belt, it is the first Kuiper-belt binary to be discovered. The study of the Pluto-Charon binary system is helpful for the understanding of planetary formation and evolution and Kuipe-belt objects. The surface feature of the binary and the evolution of the system related to the Sun or its satellites and rings have been hot in research on the Pluto-Charon system. For example, most study hold a view that the Pluto-Charon binary was formed by a giant impact. However, the internal structure and formation remain partly unexplored. This review paper compiles literature on the physical properties, formation, and basic dynamics of the Pluto-Charon system. Observational data from the New Horizons mission has advanced the understanding of the system, the review overviewed the characteristics of the Pluto-Charon binary system from the observation and analysis in the current research, such as the surface material of the two bodies. The paper also added a basic introduction to the binary system.

Accretion and Core Formation of Earth-like Planets: Insights from Metal–Silicate Partitioning of Siderophile and Volatile Elements

The origin of volatile elements, the timing of their accretion and their distribution during Earth’s differentiation are fundamental aspects of Earth’s early evolution. Here, we present the result of a newly developed accretion and core formation model, which features the results of high P–T metal–silicate partitioning experiments. The model includes well-studied reference elements (Fe, Ni, Ca, Al, Mg, Si) as well as trace elements (V, Ga, Ag, Au, S) covering a wide range from refractory to volatile behavior. The accretion model simulates the different steps of planet formation, such as the effects of continuous, heterogenous core formation at high P–T, the effect of the Moon-forming giant impact and the addition of matter after the core formation was completed, the so-called “late veneer”. To explore the “core formation signature” of the volatile depletion patterns and the quantitative influence of a late veneer, we modeled planets that would have formed from known materials, such as CI, CM, CV, CO, EH and EL meteorites, and from a hypothetical volatile depleted material, CI*. Some of the resulting planets are Earth-like in key properties, such as overall core size, major element composition, oxygen fugacity and trace element composition. The model predicts the chemical signatures of the main planetary reservoirs, the metallic core and bulk silicate planet (BSP) of the modeled planets, which we compare with the chemical signature of Earth derived previously from core formation models and mass balance-based approaches. We show that planets accreted from volatile depleted carbonaceous chondrites (CM, CV, CO and CI*) are closest in terms of major element (Si, Mg, Fe, Ca, Al, Ni) and also siderophile volatile element (Ge, Ga, Au) concentrations to the components from which Earth accreted. Chalcophile volatile elements (S, Ag), instead, require an additional process to lower their concentrations in the BSP to Earth-like concentrations, perhaps the late segregation of a sulfide melt.

Effect of a giant meteorite impact on Paleoarchean surface environments and life

Large meteorite impacts must have strongly affected the habitability of the early Earth. Rocks of the Archean Eon record at least 16 major impact events, involving bolides larger than 10 km in diameter. These impacts probably had severe, albeit temporary, consequences for surface environments. However, their effect on early life is not well understood. Here, we analyze the sedimentology, petrography, and carbon isotope geochemistry of sedimentary rocks across the S2 impact event (37 to 58 km carbonaceous chondrite) forming part of the 3.26 Ga Fig Tree Group, South Africa, to evaluate its environmental effects and biological consequences. The impact initiated 1) a giant tsunami that mixed Fe2+-rich deep waters into the Fe2+-poor shallow waters and washed debris into coastal areas, 2) heating that caused partial evaporation of surface ocean waters and likely a short-term increase in weathering and erosion on land, and 3) injection of P from vaporization of the S2 bolide. Strata immediately above the S2 impact event contain abundant siderites, which are associated with organic matter and exhibit light and variable δ13Ccarb values. This is consistent with microbial iron cycling in the wake of the impact event. Thus, the S2 impact likely had regional, if not global, positive and negative effects on life. The tsunami, atmospheric heating, and darkness would likely have decimated phototrophic microbes in the shallow water column. However, the biosphere likely recovered rapidly, and, in the medium term, the increase in nutrients and iron likely facilitated microbial blooms, especially of iron-cycling microbes.

Correlating 300 million years of catastrophes

It is frequently proposed that large bolide impacts and voluminous volcanic eruptions may be responsible for environmental catastrophes. In the conventional approach, the potential causes and consequences are matched using an age-versus-age plot, with preferential ages selected for comparison. This approach inevitably results in a one-to-one correlation, which may be misleading. To address this issue, a novel statistical metric, named conformity, has been proposed which accounts for the possibility of age coincidence resulting from random processes (i.e. bad luck coincidence). The available and updated geochronological datasets of bolide impacts, large igneous provinces, CO2-concentration peaks in the atmosphere, mass extinctions, ocean anoxic events, and climatic optima and thermal highs were subjected to a comparison in terms of their concordance. The most significant discovery is the correlation between the ages of mass extinctions and those of giant bolide impacts (crater diameter >40 km), as well as volcanism of continental large igneous provinces and CO2-concentration peaks in the atmosphere. The severity of mass extinctions appears to be dependent upon the number of simultaneously occurring causes. The most pronounced Late Maastrichtian (∼66 Ma) and Changhsingian (∼252 Ma) mass extinctions were likely caused by a combination of factors, including the simultaneous occurrence of volcanism of continental large igneous provinces, giant bolide impact and CO2-concentration rise in the atmosphere. Conversely, the ages of large igneous provinces, bolide impacts and CO2-concentration peaks are not correlated, indicating that these three causes were not interdependent.

TEMPORARY REMOVAL: Origin of Mars's moons by disruptive partial capture of an asteroid

The origin of Mars’s small moons, Phobos and Deimos, remains unknown. They are typically thought either to be captured asteroids or to have accreted from a debris disk produced by a giant impact. Here, we present an alternative scenario wherein fragments of a tidally disrupted asteroid are captured and evolve into a collisional proto-satellite disk. We simulate the initial disruption and the fragments’ subsequent orbital evolution. We find that tens of percent of an unbound asteroid’s mass can be captured and survive beyond collisional timescales, across a broad range of periapsis distances, speeds, masses, spins, and orientations in the Sun–Mars frame. Furthermore, more than one percent of the asteroid’s mass could evolve to circularise in the moons’ accretion region. This implies a lower mass requirement for the parent body than that for a giant impact, which could increase the likelihood of this route to forming a proto-satellite disk that, unlike direct capture, could also naturally explain the moons’ orbits. These three formation scenarios each imply different properties of Mars’s moons to be tested by upcoming spacecraft missions.

Comparative Analysis of Plyometric Training Protocols in Volleyball: A Meta-Analysis

Purpose: This meta-analysis synthesizes findings from 40 research studies to comprehensively examine the impact of plyometric training protocols on overall performance outcomes in volleyball athletes. Method: A systematic search identified relevant studies on plyometrics and volleyball performance. Data on training programs, performance measures, and outcomes were extracted. Statistical analysis assessed the overall effect size and addressed potential variation between studies. Findings: The constant-effects version revealed a giant wonderful common impact (Fisher r-to-z converted correlation coefficient = 0.7531, 95% CI: 0.6952 to 0.8110), affirming the fine relationship between plyometrics and volleyball overall performance. However, the random-effects model indicated giant heterogeneity among authentic effects (I² = 78.53%), prompting a radical exploration of ability sources of variability. Despite diagnosed limitations, inclusive of heterogeneity and ability publication bias, this meta-analysis underscores the want for standardized protocols and in addition studies to refine training strategies. Conclusion: The importance of this analysis lies in its contribution to proof-primarily based practices, providing valuable insights to coaches and practitioners in search of to optimize plyometric training for volleyball athletes. As a complete reference, it courses destiny research endeavors and advances know-how within the nuanced courting between plyometrics and volleyball.

Giant impact on early Ganymede and its subsequent reorientation

Ganymede has an ancient impact structure called a furrow system. The furrow system is the largest impact structure in the outer solar system, and the impact should have significantly affected Ganymede’s early history; however, its effects are poorly understood. No attention has been given to the center of the furrow system coinciding with Ganymede's tidal axis, indicating that mass redistribution induced by the furrow-forming impact caused a reorientation (true polar wander) of Ganymede. We propose that the impact ejecta created a mass anomaly that reoriented the impact site toward the tidal axis. We found that an impactor with a radius of 150 km and an incidence angle between 60° and 90° most accurately reproduces the current location of the furrow system. We predict that future explorations would reveal remnant topographic profiles or gravity anomalies associated with the furrow-forming impact and reorientation. Additionally, various possible explanations for the reorientation of Ganymede, such as an impactor-origin mascon beneath the basin or a thickness variation in the lithosphere, should be studied.

Measuring concentration in the Colombian telecommunications market

Telecommunications markets have a giant impact on countries’ economies. An example of this is the great potential offered by the internet service, which allows growth in various aspects such as productivity, education, health, and connectivity. A few companies dominate telecommunications markets, so there is a high market concentrations risk. In that sense, the state has to generate strong regulation in the sector. Models for measuring competition in telecommunications markets allow the state to monitor the concentration performance in these markets. The prediction of competition in the telecommunications market based on artificial intelligence techniques would allow the state to anticipate the necessary controls to regulate the market and avoid monopolies and oligopolies. This work’s added value and the main objective is to measure the current concentration level in the Colombian telecommunications market, this allows for competitive analysis in order to propose effective strategies and methodologies to improve competition in the future of Colombian telecommunications services operators. The main result obtained in the research is the existence of concentration in the Colombian telecommunications market.

Making a big splash: packaging imagery with implied motion enhances product liking through design appeal and naturalness perception

PurposeThis paper aims to investigate how implying movement in food packaging imagery may affect product liking. Furthermore, the underlying mechanism is investigated by studying the effect of implied motion visuals on design appeal and naturalness perception.Design/methodology/approachTwo packages of pineapple juice were designed in which the implied motion depicted in their imagery was manipulated, and a tasting experiment was conducted in which two samples of the same juice were evaluated.FindingsThe results show that the effect of packaging imagery on product liking occurs indirectly through both design appeal and the product naturalness perception. The results of a parallel multiple-mediator analysis show that (1) depicting implied motion made the package be perceived as more appealing, (2) the product corresponding to the package depicting implied motion was perceived as being more natural, and (3) both effects equally contributed to the positive effect of visuals depicting implied motion on product liking.Originality/valueOverall, these findings widen our understanding of the effects of packaging design on product liking and may help both designers and manufacturers design more appropriate packaging for their products.

Contribution of the Moon-forming Impactor to the Volatile Inventory in the Bulk Silicate Earth

The timing and mechanism by which the present-day inventory of life-essential volatiles hydrogen–carbon–nitrogen–sulfur (H–C–N–S) in the bulk silicate Earth (BSE) was established are debated. In this study we have modeled the equilibrium partitioning of H–C–N–S between core, magma ocean (MO), and atmosphere to determine whether the Moon-forming impactor (MFI) was the primary source of volatiles in the BSE. Our findings suggest that the MFI’s core and MO-degassed atmosphere were its primary H–C–N–S reservoirs. Since the MFI likely lost its MO-degassed atmosphere before the giant impact, most of the BSE’s volatiles must come from the small fraction of the MFI’s core which reequilibrated with Earth’s post-impact MO. This implies a high H–C–N–S inventory in the MFI (up to 50% of volatile-rich carbonaceous chondrites) to establish the BSE’s volatile budget. Although isotopic compositions of nonvolatile elements do not rule out the possibility of substantial volatile-rich, carbonaceous material accretion, MFI’s collisional growth from thermally metamorphosed/differentiated planetesimals makes it improbable that it contained ∼50% carbonaceous chondrite equivalent of H–C–N during its differentiation. Therefore, the MFI was unlikely the primary source of volatiles in the BSE. A significant portion of the BSE’s volatile inventory (especially H and C) likely predates the Moon-forming event. To prevent loss to space and segregation into Earth’s core, volatile-bearing materials must be delivered during the final accretion event(s) preceding the Moon-forming event. The substantial size of the proto-Earth at this stage, combined with limited metal–silicate equilibration during the Moon-forming event, facilitated the retention of these volatiles within the BSE.

Rapid formation of binary asteroid systems post rotational failure: A recipe for making atypically shaped satellites

Binary asteroid formation is a highly complex process, which has been highlighted with recent observations of satellites with unexpected shapes, such as the oblate Dimorphos by the NASA DART mission and the contact binary Selam by NASA’s Lucy mission. There is no clear consensus on which dynamical mechanisms determine the final shape of these objects. In turn, we explore a formation pathway where spin-up and rotational failure of a rubble pile asteroid lead to mass-shedding and a wide circumasteroidal debris disk in which the satellite forms. Using a combination of smooth-particle hydrodynamical and N-body simulations, we study the dynamical evolution in detail. We find that a debris disk containing matter corresponding to a few percent of the primary asteroid mass extending beyond the fluid Roche limit can consistently form both oblate and bilobate satellites via a series of tidal encounters with the primary body and mergers with other gravitational aggregates. Principally, satellites end up prolate (elongated) and on synchronous orbits, accreting mainly in a radial direction while tides from the primary asteroid keep the shape intact. However, close encounters and mergers can break the orbital state, leading to orbital migration and deformation. Satellite–satellite impacts occurring in this regime have lower impact velocities than merger-driven moon formation in e.g. planetary rings, leading to soft impacts between differently sized, non-spherical bodies. The resulting post-merger shape of the satellite is highly dependent on the impact geometry. Only moons having experienced a prior mild or catastrophic tidal disruption during a close encounter with the primary asteroid can become oblate spheroids, which is consistent with the predominantly prolate observed population of binary asteroid satellites.

How the presence of a giant planet affects the outcome of terrestrial planet formation simulations

The architecture and masses of planetary systems in the habitable zone could be strongly influenced by the presence of outer giant planets. Here, we investigate the impact of outer giants on terrestrial planet formation, under the assumption that the final assembly of the planetary system is set by a giant impact phase. Utilizing a state-of-the-art N-body simulation software, GENGA, we interpret how the late stage of terrestrial planet formation contributes to diversity among planetary systems. We designed two global model setups: 1) we placed a gas giant on the outer side of planetesimals and embryo disk and 2) we only included planetesimals and embryos, but no giant. For the model including the outer giant, we studied the effect of different giant initial masses in the range of 1.0–3.0 Jupiter masses, as well as a range of orbital radii from 2.0–5.8 AU. We also studied the influence of different initial positions of planetesimals and embryos on the results. Our N-body simulation time is approximately 50 Myr. The results show that the existence of an outer giant will promote the interaction between planetesimals and embryos, making the orbits of the formed terrestrial planets more compact. However, placing the giant planet too close to the planetesimals and embryo disk suppresses the formation of massive rocky planets. In addition, under the classical theory, where planetary embryos and planetesimals collide to form terrestrial planets, our results show that the presence of a giant planet actually decreases the gap complexity of the inner planetary system.

Rb-Sr constraints on the age of Moon formation

Determining the age of the Moon, which is commonly considered as the termination of Earth accretion has been a complex challenge for geochronology. A number of methods have been used to delineate the age of the Moon based either on absolute chronology of lunar rocks or have relied on more indirect methods using short-lived nuclides such as 182Hf that was present in the early history of the Solar System. Model ages usually require some assumptions that are sometimes controversial or harder to verify.In this study, new high precision Sr isotope data (2.4 ppm, 2SD) were obtained for a well-dated lunar anorthosite (60025) in order to better constrain the initial 87Sr/86Sr of the bulk silicate Moon. This new data is then used to model the Sr isotope evolution of the Earth-Moon starting from the beginning of the Solar System. To comply with the HfW and stable isotope constraints, we then assume that the Earth and Moon were equilibrated at the time of Moon formation. By investigating systematically all the sources of uncertainties in our model, we show that compared with previous work on anorthosites, one can tighten the constraints on the youngest age of Moon formation to no >79 Ma after the beginning of the Solar System, i.e. the Moon cannot be younger than 4488 Ma.

The Limited Role of the Streaming Instability during Moon and Exomoon Formation

It is generally accepted that the Moon accreted from the disk formed by an impact between the proto-Earth and impactor, but its details are highly debated. Some models suggest that a Mars-sized impactor formed a silicate melt-rich (vapor-poor) disk around Earth, whereas other models suggest that a highly energetic impact produced a silicate vapor-rich disk. Such a vapor-rich disk, however, may not be suitable for the Moon formation, because moonlets, building blocks of the Moon, of 100 m–100 km in radius may experience strong gas drag and fall onto Earth on a short timescale, failing to grow further. This problem may be avoided if large moonlets (≫100 km) form very quickly by streaming instability, which is a process to concentrate particles enough to cause gravitational collapse and rapid formation of planetesimals or moonlets. Here, we investigate the effect of the streaming instability in the Moon-forming disk for the first time and find that this instability can quickly form ∼100 km-sized moonlets. However, these moonlets are not large enough to avoid strong drag, and they still fall onto Earth quickly. This suggests that the vapor-rich disks may not form the large Moon, and therefore the models that produce vapor-poor disks are supported. This result is applicable to general impact-induced moon-forming disks, supporting the previous suggestion that small planets (<1.6 R ⊕) are good candidates to host large moons because their impact-induced disks would likely be vapor-poor. We find a limited role of streaming instability in satellite formation in an impact-induced disk, whereas it plays a key role during planet formation.

Study of Earth’s Obliquity Evolutionary History by Advanced Kinematic Model

NASA’s press release of ‘Moon having receded by 1 m from Earth in a quarter of century’ on the Silver Jubilee Anniversary (20 July 1994) of Man’s landing on Moon led to the development of the Kinematic Model (KM) of evolving Earth-Moon System (E-M system). Best fit KM parameters is adopted for the analysis of evolving E-M system assuming the present length of day of Earth to be 24 hours, sidereal orbital period of Moon divided by spin period of Earth = LOM(length of month)/LOD(length of day) = 27.322 and the age of Moon=4.467Gy. Using the best fit model parameters the velocity of recession of Moon is derived as 2.3cm/y as compared to 3.7cm/y by Lunar Laser Ranging experiment (Dickey et.al. 1994) [1]. Matija Cuk et.al (2016) have proposed a new model for the birth and tidal evolution of our natural satellite Moon born from impact generated terrestrial debris in the equatorial plane of high obliquity, high angular momentum Earth [2]. Using Moon’s orbital plane inclination angle (α), Moon’s obliquity (β) and eccentricity(e) of Moon’s orbit around Earth the advanced KM was developed and used for predicting the evolutionary history of Earth’s obliquity from a (semimajor axis of Moon) = 45RE = 2.96695×108 m (Cassini State Transition orbit) to the present a = 60.336RE = 3.844×108 m [3]. The present paper is sequel to the paper Sharma (2024) [5]. In the Advanced KM. (Φ)-Earth’s obliquity, (α)-Lunar orbital plane inclination, (β)-Lunar Obliquity and (e)-eccentricity of Moon’s orbit around Earth have been included. It has been shown that with the present epoch value of Φ = 23.4°, α = 5.14° , β = 1.54° and e = 0.0549, the general equation describing the evolution of E-M system from 45RE=2.96695×108 m to the present a = 60.336RE = 3.844×108 m yields (Length of Month/Length of Day) = 27.32 with fine tuning of globe-orbit parameters within its measurement error margin. But the tension between the predicted and the observed velocity of recession could not be removed even in the Advanced KM. This tension constrains Moon to be in an accelerated expanding spiral orbit where it recedes from 3.274×108 m to the present orbit 3.844×108 m in 1.2Gy time span. In the classical model this spiral expansion took 1.9Gy where it monotonically expanded spirally from 18,000Km to 384,440Km.. In the new hypothesis according to Cuk et.al. of Moon’s origin from high obliquity, high angular momentum Earth, Moon initially spirals out in chaotic manner with the lunar expansion getting stalled at Laplace Plane Transition as well as in Cassini State transition [2]. Plus in multiple-impact scenario of Moon formation according to Rufu et.al. also results in a delayed formation of full size Moon [4]. Both these factors result in a longer transit time from 18,000Km to 3.012×108 m of 3.267Gy. This results in an accelerated phase from 3.012×108 m to 3.844×108 m in 1.2Gy subsequently resulting into radial recession rate of 3.7cm/y. In the Advanced KM, 3.267Gy is spent in spiral orbital expansion from 3RE to 45RE but in fits and 1.2Gy is spent in accelerated monotonic spiral expansion from 45RE to 60.336RE. Hence this model is called fits and bound model. This also results in a much better match between observed LOD curve and theoretical LOD curve as is shown in a sequel paper [5]. In the present paper Advanced Kinematic Model analyzes the history of the evolution of Earth’s Obliqquity from the birth of Moon 4.467Gy ago to the present modern times.

Earth’s Subduction May Have Been Triggered by the Same Event That Formed the Moon

The giant impact that formed the Moon may also have led to extrastrong mantle plumes that enabled the first subduction event, kick-starting Earth’s unique system of sliding plates.

Nitrogen sequestration in the core at megabar pressure and implications for terrestrial accretion

Nitrogen (N) is the most abundant element in Earth’s atmosphere, but is extremely depleted in the silicate Earth. However, it is not clear whether core sequestration or early atmospheric loss was responsible for this depletion. Here we study the effect of core formation on the inventory of nitrogen using laser-heated diamond anvil cells. We find that, due to the simultaneous dissolution of oxygen in the metal, N becomes much less siderophile (iron-loving) at pressures and temperatures up to 104 GPa and 5000 K, a thermodynamic condition relevant to the bottom of the magma ocean in the aftermath of the moon-forming giant impact. Using a core–mantle–atmosphere coevolution model, we show that the impact-induced processes (core formation and/or atmospheric loss) are unlikely to account for the observed N anomaly, which is instead best explained by the accretion of mainly N-poor impactors. The terrestrial volatile pattern requires severe N depletion on precursor bodies, prior to their accretion to the proto-Earth.

Large impacts and their contribution to the water budget of the Early Moon

The Earth/Moon system likely results from a giant impact between a Mars-size object and the proto-Earth. This high-energy impact leads to extreme conditions under which volatile elements would not normally be preserved in the protolunar disk. However, recent measurements of lunar samples highlight the presence of a non-negligible amount of water in the Moon’s interior (from 1.2 to 74 ppm). The aim of the present work is to quantify the water contribution of the late accretion on the early Moon. Here, we use a 2D axisymmetric model with the hydrocode iSALE-Dellen to study the fate of a large impactor on a target body similar to the early Moon with a crust, a magma ocean, and a mantle. For this purpose, we compute different models to monitor the depth to which the impacted material is buried at the end of the impact event and the degree of devolatilisation of the impactor. Three parameters are explored: the crustal thickness (ranging from 10 to 80 km), the impactor radius (ranging from 25 to 200 km) and the impactor velocity (ranging from 1 to 4 times the target escape velocity). Our models show that impactors with a radius greater than 25 km impacting a partially molten lunar body with a crust thinner than 40 km could significantly contribute to the water content of the lunar mantle even for impact velocities close to the lunar escape velocity. For impact velocities greater than 3 times the target escape velocity, the impactor material is significantly molten and its water content is devolatilised within the lunar atmosphere. Depending on the water content of the impactor material and the ability of the lunar magma ocean to maintain chemical heterogeneities, the late lunar accretion following the Moon-forming giant impact could explain the differences in water content among the lunar samples.

A Giant Impact Origin for the First Subduction on Earth

AbstractHadean zircons provide a potential record of Earth's earliest subduction 4.3 billion years ago. It remains enigmatic how subduction could be initiated so soon after the presumably Moon‐forming giant impact (MGI). Earlier studies found an increase in Earth's core‐mantle boundary (CMB) temperature due to the accumulation of the impactor's core, and our recent work shows Earth's lower mantle remains largely solid, with some of the impactor's mantle potentially surviving as the large low‐shear velocity provinces (LLSVPs). Here, we show that a hot post‐impact CMB drives the initiation of strong mantle plumes that can induce subduction initiation ∼200 Myr after the MGI. 2D and 3D thermomechanical computations show that a high CMB temperature is the primary factor triggering early subduction, with enrichment of heat‐producing elements in LLSVPs as another potential factor. The models link the earliest subduction to the MGI with implications for understanding the diverse tectonic regimes of rocky planets.

Terrestrial planet formation from a ring: Long-term simulations accounting for the giant planet instability

The process leading to the formation of the terrestrial planet remains elusive. In a previous publication, we have shown that, if the first generation of planetesimals forms in a ring at ∼1 AU and the gas disk's density peaks at the ring location, planetary embryos of a few martian masses can grow and remain in the ring. In this work, we extend our simulations beyond the gas-disk stage, covering ∼200 Myr and accounting for the phase of giant planet instability, assumed to happen at different times. About half of the simulations form a pair of Venus and Earth analogues and, independently, about 10% form a Mars analogue. We find that the timing of the giant planet instability affects statistically the terrestrial system's excitation state and the timing of the last giant impacts. Hence a late instability (∼60 to 100 Myr after the Solar system's birth) is more consistent with a late Moon-formation time, as suggested by radioactive chronometers. However, the late veneer mass (LVM: mass accreted after the last giant impact) of Earth-sized planets suffering a giant impact after 80 My is usually an order of magnitude lower than the value inferred from geochemistry. In addition, the final angular momentum deficit (AMD) of the terrestrial planets tends to be too high. We tested the effect on the final AMD of the generation of debris during collisions and found that it is too small to change these conclusions. We argue that the best-case scenario is that the Moon-forming event occurred between 50 and 80 My, possibly just following the giant planet instability.