Source regions and timescales for the delivery of water to the Earth

“The D/H ratio of Earth’s water is virtually identical to that of carbonaceous chondrites, which are linked to C type asteroids in the outer main belt (Robert & Epstein 1982; Kerridge 1985; see Table 1 of Morbidelli et al.2000).”

“…and CY (“Yamato”) carbonaceous chondrite meteorites sample material from carbonaceous (C-type) asteroids that likely delivered water, organics, and other volatile species to the inner Solar System (Alexander et al., 2012; Bates et al., 2020; Cloutis et al., 2012; Morbidelli et al., 2000).”

“Previous studies have hypothesized that NEOs are responsible for the early delivery of water and organic materials to Earth ( Morbidelli et al. 2000 ) , and recent missions such as Hayabusa2 and OSIRIS-REx have continued to fi nd organic materials on NEO surfaces ( Kaplan et al. 2021; Naraoka et al.…”

“…O’Brien et al., 2014; Petit et al., 2001; Raymond et al., 2004) and planetesimals and dust that had migrated from behind the Jupiter’s orbit (Levison et al., 2001; Morbidelli et al., 2000; Ipatov, 2000; Marov and Ipatov, 2001, 2005, 2020; Ipatov and Mather, 2003, 2004, 2006, 2007; Ipatov, 2010).”

“…history of our solar system, place constraints on protosolar disk models, probe a potential primordial 1 source of terrestrial water (cf. Morbidelli et al. 2000, 2012; Mottl et al. 2007; Owen 2008), and possibly gain insights into the conditions that allowed life to arise on Earth and…”

“ce in planetary science because they appear to be repositories of ice in a region of the Solar system that has been suggested, on independent grounds, as a potential contributor to the Earth’s oceans [62]. The reasoning behind this is as follows. The Earth probably formed too hot to have accreted and retained much wat…”

“The correlation between the water content and the orbital distance of asteroids (assuming that their present orbital distance does not differ too much from where they formed) suggests that material formed at 1 AU was dry ( Morbidelli et al., 2000 ).”

“... the ≤1 Myr “sticking” period of dust grains in the early solar nebula and ending up with the ∼100 Myr accretion period of tens to hundreds of planetary embryos with sizes up to that of Mars (for a short summary of previous works, see Abee et al., 2002); (ii) the direct capture of gases from the solar nebula (Urey,…”

“Some (e.g., Dauphas et al. 2000; Morbidelli et al. 2000; Drake and Righter 2002, Robert 2001), consider the high D/H ratio in these comets as evidence against a cometary origin of most of the terrestrial water.”

“In addition, dynamical studies have also looked at the cometary delivery to Earth (Joiret et al., 2024, 2023; Morbidelli et al., 2000; Raymond et al., 2004).”

“…of giant planets, and their consequences for the eventual architecture and the potential hab-itability of HZ planets is an active area of research (Morbidelli et al. 2000; Morbidelli & Raymond 2016; Clement et al. 2022), particularly as we seek to reconcile solar system formation scenarios with…”

“Fulle et al. (2017) supposed that, though the volume fraction of water in comet 67Р and transNeptunian objects is approximately 20 per cent, the bodies born close to the water-ice condensation”

“It is also more coherent with dynamical accretion model and distribution of oxidized material within the early solar system (Izidoro et al., 2021; Morbidelli et al., 2000; Raymond & Izidoro, 2017; Raymond et al., 2009).”

“…Walsh et al. 2011), this information could then place constraints on the distribution of ice in the primordial solar system, and in turn, constrain protosolar disk models and provide insights into terrestrial water delivery (e.g., Morbidelli et al. 2000; Raymond et al. 2004; O’Brien et al. 2006).”

“The outer asteroids are icy C-class objects (e.g. Abe et al. 2000; Morbidelli et al. 2000) whereas the inner asteroid belt objects contain little water.”

“In any event, they could still make contribution to the terrestrial water source reservoir within the dynamical constraint of being no more than 10% in total as estimated by Morbidelli et al. (2000).”

“…Jewitt 2006), main-belt comets (MBCs) have received significant interest largely due to their potential for improving our understanding of the role of main-belt objects in the primordial delivery of volatile material (i.e., water) to the early Earth (e.g., Morbidelli et al. 2000, 2012; Owen 2008).”

“The water (and perhaps other volatiles) now present in the Earth and Mars (and Venus?) accreted later either by the drift back of icy planetesimals or from comets that had formed originally in the region of Jupiter (Cyr et nl., 1998, 1999; Morbidelli et al., 2000).”

“, 2003, 2007) and migration of planetesimals from beyond Jupiter’s orbit (Morbidelli et al., 2000; Levison et al., 2001; Marov and Ipatov, 2001; 2005; Ipatov and Mather, 2004, 2006, 2007; Ipatov, 2010).”

“Planetary formation methods (e.g., Morbidelli et al. 2000; O’Brien et al. 2018) suggest that terrestrial, HZ planets tend to be either completely ocean covered or completely land covered.”

“…can acquire water from in situ and gas disk processes (Young et al. 2023; Kral et al. 2024), the most well-studied mechanism for water delivery to the Earth relies on impacts from water-rich bodies that formed beyond the snow line (Morbidelli et al. 2000; Meech et al. 2019; Raymond & Izidoro 2017).”

“As such, they are key to understanding the properties and chemical compositions of planetary bodies (e.g., Chambers 2001; Morbidelli et al. 2000; ¨Oberg & Wordsworth 2019).”

“Studies have been conducted to elucidate material mixing during and after the solar system formation (e.g., Morbidelli et al. 2000; O’Brien et al. 2014).”

“The Earth likely accreted water all along with its formation (Morbidelli et al., 2000; Keppler and Smyth, 2006), and the acquirement of equilibrium water storage in feldspars, pyroxenes, and olivine might be possible.”

“…to have been instrumental in delivering water and other volatiles to the inner parts of the system, whether it happened after formation (Chyba 1990; Morbidelli et al. 2000; Abramov & Mojzsis 2009; Carter-Bond et al. 2014; Grazier 2016) or during formation (Raymond et al. 2006; Raymond & Izidoro…”

“In addition, the origin water might be transported to the primitive Earth via comets, although it is under debating (Morbidelli et al. 2000; Altwegg et al. 2015).”

“A host of discoveries on the origins of organic and carbonaceous matter and delivery to Earth, D/H ratio in water (Hartogh et al. 2011; Morbidelli et al. 2000; Altwegg et al. 2015; Hässig et al. 2015), and presence of PAH precursor molecules in chondrites (Plows et al. 2003; Engrand & Maurette…”

“Since H2 molecules are mobile, even in densely packed MgO, they can diffuse away from the 2Mg + vacancy site leaving behind an 2Mg + vacancy charge wise compensated by a peroxy anion, 22O − : ( ) ( )• •Mg 2Mg O OH V HO V H O x x x i ′′ ′′ + ⇔ (4b) Equation (4b) indicates that, when the H2 molecules may move away from…”

“(e.g., Chambers and Wetherill, 1998; Agnor et al., 1999; Morbidelli et al., 2000; Raymond et al., 2004).”

“Primitive asteroids can transport water and complex organic molecules, which may have reached the primitive Earth through impacts, contributing to the emergence of life on the planet (Morbidelli et al. 2000; Izidoro et al. 2013).”

“…of the water snowline has implications for the delivery of water to terrestrial planets, offering clues to the origin of Earth’s oceans ( e.g., A. Morbidelli et al. 2000, 2012, 2016; K. J. Walsh et al. 2011; S. Ida & T. Guillot 2016; T. Sato et al. 2016; S. N. Raymond & A. Izidoro 2017; S. Ida…”

“Interestingly, the D/H ratio in Earth’s oceans closely matches that found in certain meteorites and a few comets from the Jupiter family [2], [17].”

“In-coming comets can deliver volatiles to replenish atmo-spheres (e.g. A. Morbidelli et al. 2000; F. J. Ciesla et al. 2015) or conversely, erode them through high energy collisions (e.g. V. Shuvalov 2009; Q. Kral et al. 2018).”

“65) is compatible with a CM-like reservoir 66 .”

“…water on Earth has long been debated because, in the standard model of planetary formation, volatiles condense beyond the ice line during the protoplanetary disk phase, which is thought to be located at approximately 3AU from the Sun (Hayashi, 1981; Morbidelli et al., 2000; Podolak & Zucker, 2004).”

“Our above estimates of the fractions p E of bodies collided with the Earth are not differed much from estimates by Morbidelli et al. (2000), who obtained the probability of a collision of a particle with the Earth to be of the order of 10 − 6 - 3 ⋅ 10 − 6 per particles in the 5 – 8 AU region,…”

“The origins of water on Earth, the processes by which it was deposited, and how those processes relate to the evolutionary model of our solar system remain a contentious issue [1,2,3] in planetary science.”

“Most of these binaries are primitive asteroids, i.e., rich in organic and volatile compounds, probably formed beyond the outer main belt, which can provide clues about the origin of water and prebiotic molecules on the early Earth (Morbidelli et al., 2000; Izidoro et al., 2013).”

“…by the capture of pebbles drifting through the inner solar system on their journey to the Sun (Ida et al. 2019), or the addition of water may have been a late veneer acquired via impacts of asteroids or comets after planet formation was mostly complete (Morbidelli et al. 2000; Owen et al. 1992).”

“Figure 1 of Morbidelli et al. (2000) indicates that a fraction fin∼ 10%–15% of all asteroids are deflected onto orbits with perihelia 1 au.”

“Asteroid impacts may have delivered water to the surface of the Earth (Morbidelli et al. 2000; Martin & Livio 2021) and led to the formation of the Moon (e.g. Ćuk & Stewart 2012; Canup 2012).”

“1) × 10−4 have led to models in which asteroids were the main source of Earth’s water [6], with ≤ 10% being delivered by comets.”

“Previous studies have claimed that Earth’s water originated from asteroids (Morbidelli et al. 2000; Mottl et al. 2007; Campins et al. 2010).”

“They may also be useful for investigating hypotheses that objects from the main asteroid belt may have played a significant role in the primordial delivery of water to the terrestrial planets (cf. Morbidelli et al. 2000, 2012; Mottl et al. 2007).”

“Some such bodies might survive passage through the Earth’s atmosphere (Madiedo et al., 2013) and could already be present, but unrecognised, in terrestrial meteorite collections.”

“The transport of comets from the outer to inner Solar System may be a source of water on Earth (e.g., Morbidelli et al., 2000).”

“Water is most essential part of this planet for all types of flora and fauna (Marty et al. 2006; Morbidelli et al. 2000).”

“Study of volatile-bearing minor planets helps us understand the origins of terrestrial water ( e.g., A. Morbidelli et al. 2000; H. H. Hsieh & D. Jewitt 2006; P. Hartogh et al. 2011; C. O. Chandler 2022 ) and informs planetary defense ( H. F. Levison & M. J. Duncan 1997 ) .”

“Exogenous sources included migration of bodies from the outer part of the main asteroid belt (Ipa-tov, 2021; Lunine et al., 2003; Morbidelli et al., 2000, 2012; O’Brien et al., 2014; Petit et al., 2001; Raymond et al., 2004) and migration of planetesimals from beyond Jupiter’s orbit (Ipatov, 2010,…”

“However, Earth is thought to have formed and accreted up to 70 oceans worth of water (Morbidelli et al. 2000; Raymond et al. 2006; Chassefière et al. 2012), making this a conservative estimate for initial water inventory.”

“Conversely, the D/H ratio in carbon-rich chondroid meteorites matches quite well the Earth’s values, pointing to a possible role of these reservoirs in forming the atmospheres of rocky planets (Morbidelli et al., 2000).”

“Avant la mesure de Hartley 2, il avait été proposé que la source principale d’eau sur Terre provienne des astéroïdes, les comètes y contribuant pour moins de 10 % (Morbidelli et al. 2000).”