Update of the initial descriptions and distributions of individual Ryugu samples and preparation
for curation of OSIRIS-REx returned samples
Yada T.1, Abe M.1, Miyazaki A.1, Yogata K.1, Nagashima K.1, Hatakeda K2., Nakato A.1, Hitomi Y.2, Sugiyama Y.1, Tahara
R.1, Nakano A.1, Ojima T1, Nishimura M.1, Okada T.1, Tsuchiyama A.3, Michikami T.4, Sakamoto K.1, Kanemaru R.1,
Kumagai K.2, Soejima H.1, Fukai R.1, Ishizaki T.1, Sugahara H.1, Suzuki S.1, Sugita S.5, Cho Y.5, Yumoto K.5, Yabe Y.5, Mori
S.5, Aikyo Y.5, Furuichi K.5, Bibring J.-P.6, Pilorget C.6, Brunetto R.6, Riu L.6, Loizeau D.6, Lourit L.6, Hamm V.6, LequertierG.6, Carter J.6, Le Pivert- Jolivet T.6, Lantz C.6, Tachibana S.5, Usui T.1, and Fujimoto M1
1. JAXA, 2. Marine Works Japan, 3. Ritsumeikan Univ., 4. Kindai Univ., 5. Univ. Tokyo, 6. Institut d'Astrophysique Spatiale
After the return of Ryugu samples by Hayabusa2 in Dec 2020, they have been described in the Extraterrestrial Sample
Curation Center (ESCuC) of JAXA and distributed to the initial analyses and phase-2 curation teams for further detailed analyses.
In order to provide fundamental information of the samples to researchers, a series of initial descriptions on bulk and individual
Ryugu samples has been conducted non-destructively under purified nitrogen condition such as optical microscopic observations,weight measurements, infrared spectral measurements with an FT-IR, an infrared microscope MicrOmega, and visible spectral
measurements using a monochronic microscope with six filters [1, 2]. These initial descriptions data are open to the public at thewebsite of the Ryugu Sample Catalog (https://darts.isas.jaxa.jp/curation/hayabusa2/).
So far, 604 individual Ryugu grains are handpicked and described, which comprise nearly 40wt% of bulk samples
recovered from the Chamber A and C. As noted previously [1], Chamber A samples corresponds to those from the first
touchdown site and Chamber C corresponds to the second one where is close to the artificial crater produced on the asteroid by
the Small Carry-on Impactor of Hayabusa2 [3]. Their mass distributions are shown in Fig. 1. The power index of the cumulative
mass distribution of both Chamber A and C is -1.28, which is slightly steeper than the result of catastrophic impact experiments(-0.4 to -1.1) [4]. This indicates fragmentation after the past catastrophic disruption of the Ryugu parent body and re-accretionto the Ryugu body may have occurred on Ryugu’s surface. The infrared spectral results with FT-IR (264 grains) and with
MicrOmega (174 grains) are under detailed evaluations. So far, 202 grains have been analyzed for their visible spectra with themonochronic microscope with six filters. Their data are detailed in [5].
The first announcement of opportunity (AO) for Ryugu samples was announced from last Dec. In the 1st AO, 57
proposals were submitted and 40 of them were selected for sample distributions. The distributions of Ryugu samples to theselected PIs will be finished soon. The application of proposals for 2nd AO will be closed in the beginning of this Nov. After aseries of reviewing and selection processes, the sample distributions to the selected PIs will start in the beginning of next year.
Based on the Memorandum of Understanding (MOU) between JAXA and NASA, JAXA will receive 0.5wt% ofreturned samples (estimated to be approximately 1.25g [6]) by the OSIRIS-REx. In order to curate the allocated OSIRIS-REx
samples, a new clean room has been prepared in the ESCuC, and new clean chambers, which are designed based on the
Hayabusa2 clean chambers, will be installed in the next fall. The initial analyses and subsequent distribution of the OSRIS-REx
samples are still under discussion, though we aim to primarily focus on comparative studies between Ryugu and Bennu samples.

Fig. 1. A cumulative mass distribution of individual Ryugu grains from
Chamber A, C, and A+C. The cumulative mass distribution from Chamber
A shows a regular straight distribution whereas that from Chamber C appears
irregular in >10mg weight range. This might indicate that the SCI impact by
the Hayabusa2 might have disturbed the weight distribution of surface
regolith on 2nd touchdown point [3].

References[1] Yada T. et al. 2022. Nat. Astron. 6, 214. [2] Pilorget C. et al. 2022. Nat. Astron. 6, 221. [3] Arakawa M. et al. 2020.
Science 368, 67. [4] Michikami T. et al. 2016. Icarus 264, 316. [5] Yumoto K. et al. 2022. this meeting. [6] Lauretta D. et al.
2022. Science 377, 285.

The Direct Asteroid Redirection Test (DART) – Preliminary Findings
O.S. Barnouin1 and the DART Investigation and Engineering team.
The Double Asteroid Redirection Test (DART) is the first successful full-scale demonstration of the kinetic
impactor technology to deflect an asteroid. While an asteroid impact large enough to cause regional devastation
on Earth is unlikely, and no known asteroid poses a threat to Earth, the consequences of such an impact would besevere (e.g., Defending Planet Earth, 2010; National Near-Earth Object Strategy and Action Plan, 2018). Here we
provide a quick overview of the objectives of the DART mission, and some preliminary results.
Acknowledgments: This research was supported by the the DART mission, NASA Contract No. NNN06AA01C
to JHU/APL and the Italian Space Agency (ASI) within the LICIACube project (ASI-INAF agreement AC n.
2019-31-HH.0).

Radiolytic solar wind water in rims on an Itokawa regolith grain
John P. Bradley1 and Hope A. Ishii1
1
Hawaii Institute of Geophysics and Planetology, University of Hawai‘i, Honolulu, HI 96922, USA
Introduction: The detection using electron energy-loss spectroscopy (EELS) of OH/H2O in-situ in vesicles within sputteredrims on interplanetary exposed to the solar wind for ~104-105 years provided the first direct evidence that the interaction of thesolar wind with oxygen-rich silicates produces water; additional confirmation was provided by detection of water using EELS
in the sputtered rims on silicate mineral standards following proton irradiation at solar wind fluences [1]. The results are
consistent with OH/H2O signatures on the surface of airless bodies observed by remote spectroscopy, e.g. [2]. Regolith fromthe S-type asteroid Itokawa returned by the Hayabusa mission enables us to further explore the effects of solar wind irradiation
on airless bodies. Enrichments in water and hydroxyl in the solar wind-irradiated rim of an Itokawa olivine grain and a labirradiated olivine standard have been detected using atom probe tomography [3]. Here we describe detection of OH/H2O inthe surface of another Itokawa olivine grain using electron energy loss spectroscopy (EELS).
Experimental procedure: Hayabusa regolith particle RA-QD02-0332 was carbon-coated for imaging and elementmapping in a focused ion beam-scanning electron microscope (FIB-SEM: FEI Helios 660 with Oxford Instruments EDS), and
FIB sections of selected regions were extracted at Univ. Hawai‘i using Pt protective straps. These were further analyzed on(scanning) transmission electron microscopes at the Molecular Foundry (S/TEM: FEI Titan ChemiSTEM with EDS, TEAM
1.0 with Gatan Continuum GIF for EELS).
Results: RA-QD02-0332 is a ~48µm grain that consists of olivine, pyroxene, plagioclase and, likely, K-feldspar. In SEM
imaging, glassy melt splashes with degassing vesicles are visible in multiple locations on the surface. Fractures are observed aswell as significant fine-grained adhering material, including angular fragments and spheroidal particles with melt droplet
appearance. Two FIB sections crossing fine-grained material contain small mineral crystals of albitic plagioclase and fayalitic
olivine with lesser amounts of high-Ca pyroxene and iron-sulfide. Fine grain sizes range from ~100 nm to several microns
across, and grain shapes range from angular to euhedral to rounded, consistent with some brecciation on the parent body.
Another FIB section contains a ~4 µm plagioclase grain with fracture and defects in the interior consistent with shock, anamorphized rim on one face that has lost most of its Na and some Ca relative to the underlying crystal, and surficial lacy Ferich material that is likely remnants of the impactor.
A FIB section through an olivine crystal shows melt splash glass and a ~40 nm in thick vesiculated amorphous rim on thesurface (Figure 1a). Energy dispersive spectral mapping shows that the amorphous rim has a composition similar to theunderlying olivine but with minor additional Al and Ca present. An EELS spectrum from one of the vesicles shows features at~8 and ~13.5 eV features. These features correspond to the energy gap and H-K core scattering edge from hydroxyl and/or
molecular water, like those we previously observed in rims on IDPs, water in a liquid cell, proton irradiated silicate standards
and electron beam-damaged talc and brucite [1,4]. Weaker features are observed in the amorphous rim off the vesicle.
Figure 1: (a) Darkfield image and highermagnification inset show vesicles in amorphous
rim on Itokawa olivine,.(b)EELS low-loss
spectrum shows ~8 eV and ~13 eV featuresfrom one of the vesicles superimposed on theamorphous rim volume plasmon.
Discussion: The vesiculated amorphous rimon the olivine crystal in Itokawa grain RAQD02-0332 establishes that it was exposed tothe solar wind on the surface Itokawa.
Detection of water by EELS confirms the prioratom probe tomography detection of water inanother solar wind-irradiated rim on an Itokawa
olivine [3]. The relatively low intensity of the features observed here from the vesicle in the amorphous rim on Itokawa olivine
compared to those observed in some vesicles in IDPs (Fig 1c), may be a consequence of a shorter (solar wind) exposure agesof Itokawa regolith grains relative to IDP orbital exposure ages.
References: [1] Bradley J.P. et al. (2014) Proceedings of the National Academy of Sciences 111:1732. [2] Li S. andMilliken R.E. (2017) Science Advances 3:e1701471. [3] Daly L. et al. (2021) Nature Astronomy 5:1275. [4] Zhu C. et al.
(2019) Proceedings of the National Academy of Sciences 116:11165-11170.

Importance of Material Properties on the Thermal Evolution Models of Parent Bodies
Jonas Hallstrom1 and Maitrayee Bose2
1
Department Of Physics, Arizona State University, Tempe, Arizona 85287, USA, jlhallst@asu.edu
2School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287, USA
Introduction: A majority of the chondritic materials in our solar system originated and were partially processed in the first~10 million years after time 0, defined as the time when calcium-aluminum inclusions (CAIs) condensed [e.g., 1]. The primaryheating mechanism for the parent body asteroids was radiogenic heating due to the decay of 26Al [1]. Thermal evolution
models alongside experimentally determined physical properties, such as the specific heat capacity, have been used to placeconstraints on the sizes and times of formation of various chondritic asteroid parent bodies [2−4]. These models allow anunderstanding of the processes in small bodies that formed early in the solar system history, and are a link to the shapes andgeology of the asteroids observed during flyby or sample return missions.
While there are several sources of error in thermal evolution models that vary in their significance, we investigated the effectof uncertainty in some of the material properties, namely aluminum abundance, specific heat capacity, and thermal diffusivity.
We adopted the thermal evolution model for the parent body of asteroid Itokawa described by [5], determined uncertainty
ranges for the aforementioned material properties, and placed new constraints on the radius and formation time of Itokawa’s
parent body.
Methods: Our thermal evolution model follows the common approach of approximately solving the radial heat conduction
equation using finite difference methods. This calculation also incorporates assumptions about the material properties and theinitial and boundary conditions for the system, for which we followed the recipe from [5]. Temperature data from the thermal
evolutions calculated by this model were interpolated over the whole range of realistic formation time and radius values, andthen compared with known thermal constraints on the parent body of Itokawa [5]. Subsequently, we determined uncertainty
ranges for the material properties from the literature: -10% to +10% for specific heat capacity [2, 6], -10% to +200% forthermal diffusivity [6, 7], and -14% to +16% for aluminum abundance [2, 8], and repeated the calculations to ascertain theeffects of these uncertainties.
Results: Without accounting for any uncertainties, our model predicts a radius greater than 20.5 km and a formation time
range between 1.87 and 2.24 Ma after the formation of CAIs for the parent body of Itokawa. This is in agreement withprevious results [5; >20 km, 1.9-2.2 Ma]. Accounting for the uncertainty in all three parameters results in a minimum radius of
18.5 km and a formation time range between 1.6 and 2.5 Ma after CAIs.
Discussion: Although the minimum size for Itokawa’s parent body reduced only by about 10%, the formation time range issignificantly expanded, after taking the uncertainties into account. We observed that 10% uncertainties in both specific heat
capacity and aluminum abundance contributed approximately an additional ±0.1 Ma onto the computed range of valid
formation times of the body. Though the exact effects of uncertainty in material parameters on the accuracy of thermal
evolution models is likely highly dependent on the specific form of the model, and the values and conditions used therein,
aluminum abundance and specific heat capacity are fundamentally important to all thermal evolution models. The efficacy ofsuch models is therefore significantly dependent on the existence of precise measurements of these material properties.
References[1] Desch S.J. et al. 2018. The Astrophysical Journal Supplement Series 238(1):11. [2] Henke S. et al. 2012. A&A 537:A45.
[3] Sugiura N. and Fujiya W. 2014. Meteoritics & Planetary Science 49(5):772–787. [4] Blackburn T. et al. 2017. Geochimica
et Cosmochimica Acta 200:201–217. [5] Wakita S. et al. 2014. Meteoritics & Planetary Science 49(2):228–236. [6] Yomogida
K. and Matsui T. 1984. Earth and Planetary Science Letters 68(1):34–4. [7] Henke S. et al. 2016. A&A 589:A41.
[8] Jarosewich E. 1990. Meteoritics 25(4):323–337.

Molecular descriptors for dictating the aqueous-alteration-induced organic decomposition incarbonaceous chondrites and return sample from Ryugu asteroid
Yamei Li1, Hiroyuki Kurokawa1, Yasuhito Sekine1,2, Junko Isa3, Norio Kitadai1,4, Yoko Kebukawa5, Kosuke Fujishima1, andYuko Nakano1
1
Earth-Life Science Institute, Tokyo Institute of Technology
2Institute of Nature and Environmental Technology, Kanazawa University
3
Planetary Exploration Research Center, Chiba Institute of Technology
4Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Institute for Extra-cutting-edge Science andTechnology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
5
Faculty of Engineering, Yokohama National University
Background. Carbonaceous chondrites (CCs) are among the most primitive material in our Solar System. Organics such asamino acids are ubiquitously found in CCs and have been invoked to serve as life’s building blocks to promote the origin oflife on Earth and possibly elsewhere. Meanwhile, the chemical diversity of amino acids records the chemical evolution eventsprior to and after the accretion of their parent bodies. In the past decade, the advancement of analytical instrumentations, anincreasing supply of samples from various CC subgroups, and the development of a more accurate petrographic classification
system of CCs have facilitated the study on how parent body processes have shaped the organic distributions. However, there
is a large discrepancy between experimental results and meteoritic records. Previous studies show that amino acids can besynthesized in aqueous solution containing primordial molecules, suggesting that amino acids would have accumulated upon
extended aqueous activity. Nevertheless, amino acids are found to be depleted in more aqueously altered CCs, pointing to apotential “Water Paradox”.
In our previous study [1], we discovered a new low-temperature geo-electrochemical process which provides a possible
solution to the “Water Paradox” and proposed a new molecular descriptor of aqueous alteration degree. The geoelectrochemistry model was proposed based on the redox gradientamino acids
serpentinethat could be generated via water/rock interaction (Fig. 1). H 2 gas,magnetite
serpentinee−etc.
FeS, NiS
generated through water/rock interaction, serves as the electronetc.
H2
donor to drive the geo-electrochemical alteration of amino acids at
HO2+
H2O Na ,O
Hthe interface of mantle fluid and minerals. We found that three
CO2-rich,
H2-rich,−emuddy
porousH2model amino acids (glycine, alanine, and valine) werewaterrockrich
rich
amino
decomposed to their amine and hydroxy acid analogs, and both ofmantle
core
acids
crust
these two compound classes were found to coexist with amino
Figure 1. Model of geo-electrochemical alteration of aminoacids and enriched in heavily aqueously altered CR chondrites.
acids induced by water-rock interaction in icy planetesimals
These results suggest that decomposition of amino acid dominates(a parent body of CCs). A difference in the water/rock mass
the chemical evolution of the parent body of CR chondrites.
ratio (W/R) between the core (grey) and mantle (blue) leads
to gradients in pH and redox.
However, the discussion was only limited to CR chondrites due toinsufficient data of amine and hydroxy acid abundances in otherCC subgroups.
Recently, we extended this model to other types of amino acids and found that the electrolysis of glutamate (Glu) andasparate (Asp) generates γ-aminobutyrate (γ-ABA) and β-alanine (β-Ala), respectively, via reductive decarboxylation. The
enrichment of these products with respect to their amino acid precursors is found in heavily aqueously altered CR 2.0–2.4, CI
as well as a return sample from asteroid Ryugu. These data suggest that the relative enrichment of derivative products canserve as a general descriptor of aqueous-alteration-induced organic decomposition. A geochemical model based on the waterrock differentiation in the parent icy plantesimals [2] was proposed to account for the observation.
Experiments and results. Electrolysis of amino acids was conducted at ambient temperature (25 oC) in an electrochemicalcell made of two compartments separated by a proton-exchange membrane. In the cathodic chamber, iron or nickel sulfide
catalysts were placed on a carbon paper electrode in a pH-7 phosphate buffer containing 20 mM of Glu or Asp. An anoxic
condition was maintained by continuous argon gas flow during electrolysis. Using these two sulfides as catalysts, theconversion of Glu and Asp to various products, including decarboxylated products (γ-ABA and β-Ala, respectively), αhydroxy acids (2-hydroxyglutarate and malate, respectively) was observed after 14-day electrolysis of amino acids at−0.5~−1.0 V versus standard hydrogen electrode (vs. SHE). The electrode potential represented the magnitude of the redox
gradient (H2 enriched core versus bicarbonate-buffered mantle) and is equivalent to the reduction potential of H2/H+ redox

couple under specific pH and temperature conditions. A more negative electrode potential corresponds to a condition withmore alkaline pH or higher temperature.
Discussion. The well-documented abundances of these four chemically related amino acids (namely, Glu, Asp, γ-ABA, and βAla) among different CC subgroups allow a general comparison of amino acid distribution and discussion on the impact of
aqueous-alteration-induced decomposition processes (Fig. 2). Although no clear tendency can be deduced from the absoluteabundances of these amino acids (Fig. 2a-2d) among different CCs, obvious enrichments of γ-ABA over Glu (Fig. 2f) and βAla over Asp (Fig. 2e) were discovered among heavily aqueously altered CR2.0–2.4, CI chondrites; contrastively, such
enrichments are not observed in CM1–2.9 and primitive CR2.7–2.8 chondrites. Such difference implys that the impact of geoelectrochemical decomposition of amino acid highly depends on the chemical composition, degree of water-rockdifferentiation and the location of parent bodies in the early Solar System (Fig. 2i-2j). While we do not rule out parent bodyformation at various locations to account for different degree of aqueous-alteration-induced organic decomposition, here we
propose another senario where CI, CM and CR sample different regions of water-rock-differentiated parent icy planetesimals
formed beyond the CO2 snow line. The accreted CO2 ice and H2O ice were melted by the heat generated via the decay of shortlived radionuclides. The icy planeteismal experienced water-rock differentiation and features a rock-rich core and water-richmantle as discussed by Kurokawa et al. [2]. The low water/rock mass ratio (W/R) in the core generated alkaline, H 2-rich fluid
upon water/rock interaction. In contrast, the high W/R ratio in the mantle generated neutral to weakly alkaline, CO2-rich fluid
where geo-electrochemistry proceeded and decomposed Glu and Asp to γ-ABA and β-Ala, respectively. Therefore, in light of
the high abundance ratio of γ-ABA/Glu and β-Ala/Asp in CI and CR 2.0–2.4 chondrites, it is possible that these chondrites
originally sourced from the mantle (Fig. 2i-2j). This is consistent with the observation of similarly high enrichment in thesamples obtained from the surface of Ryugu asteroid (Fig. 2e~2h), which was suggested to be CI-like body with an outer Solar
System origin [5, 6] and processed by low temperature aqueous alteration (30 oC) [6]. In contrast, the very low abundance
ratios revealed in CM1–2 and CR2.7–2.8 chondrites indicate that they were sourced from the rock-rich core, as no geoelectrochemical alteration of amino acid could proceed there. CR chould span a wide range of rock/mantle transition region,
thus show a wide range of decomposition degree. Based on these results and discussions, we propose that the relative
abundance ratios of derivative products/organic precursors can serve as a general molecular descriptor for dictating theaqueous-alteration-induced organic decomposition as well as sheding insight into the water/rock differention status of icy
planeteismals at their early evolution period [2]. This can shed implications on the chemical evolution and cycling within theparent bodies, as well as provide chemical models for guiding the future space missions to asteroids and return sample analyses.

20

a: [Asp]

100 e: [b-Ala]/[Asp]i
CI1

CR2.0~2.4
CR2.7~2.80080

150 b: [Glu]100f: [g-ABA]/[Glu]40

CM2.5~2.9

CI and CR 2.0-2.4 chondrites areremnants of water-rich mantle

CM1
CO2 snow line

Formosesynthesis

CM1-2.9 and CR2.7-2.9
chondrites are remnants of rockrich core50
0c: [b-Ala]50

0d: [g-ABA]
50

Abundance ratio

Abundance (nmol g-1)

Ryugu

Ryugu

50

10

0
2 g: [Asp]/[Glu]

j
0

H2
+

GRO 95577
MIL 090001
MIL 090657
GRA 95229
EET 92042
QUE 99177
Asuka 12236
Paris
Murchison1
Murchison2
Murchison3
Murchison4
Murchison5
Murchison6
Murchison7
Murchison8
Murchison9
Murray1
Murray2Mighei
ALH 88045
MET 01070
LAP02277
Orgueil1
Orgueil2
Orgueil3
Ryugu
FS_1
FS_2
FS_3

GRO 95577
MIL 090001
MIL 090657
GRA 95229
EET 92042
QUE 99177
Asuka 12236
Paris
Murchison1
Murchison2
Murchison3
Murchison4
Murchison5
Murchison6
Murchison7
Murchison8
Murchison9
Murray1
Murray2Mighei
ALH 88045
MET 01070
LAP02277
Orgueil1
Orgueil2
Orgueil3
Ryugu
FS_1
FS_2
FS_3

e−

,OH
H2O Na-0

FeS, NiS,
carbonate,saponiteetc.

amino acids

h: [b-Ala]/[Glu]
60
30

0

serpentine
magnetiteetc.

H2-rich, CO2depleted,
pH~14, rockrich coree−

H2O
CO2-rich,
pH ~ 7~9,
water-richmantleH2amino acids
crust

Figure 2. The molar abundances of aspartate (a), glutamate (b), and the decarboxylated products β-Ala (c), and γ-ABA (d) in different
carbonaceous chondrites and Ryugu sample reported recently [3]. FS_1–3 indicates the Formose-type synthesis results at 90–150 oC
reported by Kebukawa et al. [4]. e, f, g, and h plotted the molar ratios of β-Ala/aspartate, γ-ABA/glutamate, aspartate/glutamate, and βAla/glutamate, respectively, in these samples. i and j depicted the model that can explain the different decomposition degree in e–hamong different carbonaceous chondrite subgroups resulted from geo-electrochemistry in a water-rock differentiated parent body.

References[1] Y. Li et al. Nat. Commun. 2022, 13:4893. [2] H. Kurokawa et al., AGU Adv. 2022, 3(1). [3] E. T. Parker et al., 53rd Lunarand Planetary Science Conference, 2022, 2651. [4] Y. Kebukawa et al., , Sci. Adv. 2017, 3 : e1602093. [5] T. Yada et al., Nat.
Astron. 2022, 6(2). [6] M. Ito et al., Nat. Astron. 2022.

The reproduction experiment of radial pyroxene chondrules using aerodynamic levitator furnace
in a reduced condition
Tomoyo Morita1, Tomoki Nakamura1 and Kana Watanabe1
1
Tohoku University, Japan
We performed reproduction experiments of radial pyroxene chondrules (RP chondrules) using the aerodynamic
levitator furnace in a reduced condition that simulates the environment in the protoplanetary disk [1]. Chondrules were formedby flash heating of solid precursors and crystallization during subsequent cooling. They show characteristic texture thatrefracts thermal histories and the local environment of the protoplanetary disk [2]. In this study, we attempt to constrain thethermal history of the RP chondrules, which formed at high temperature by total melting of the precursor material.
The experiments were performed using the aerodynamic levitator furnace at Tohoku University [3]. The sample
spheres were levitated by Ar-H2 gas (Ar = 97 %, H2 = 3 %), heated to melt by a CO2 laser (LC-100NV from DEOS), andcooled to crystallize in a non-contact state. The cooling rates were from 1 to ~1000 °C/s in the temperature range from 1600 °C
to 500 °C. During cooling small glass particles called "seed" impacted the molten sample to crystallize pyroxene. The furnace
was enclosed in an acrylic container and the inside of the container was replaced with Ar-H2 gas to achieve a reducing
atmosphere of ΔIW from -1.5 to -0.5. The starting material was a mixture of oxide powders (SiO2, MgO, FeO, CaO, Al2O3,
and Na2O) with three different compositions similar to natural RP chondrules [4-6]. No metallic Fe was used. During theexperiment, images of the samples were taken with a CCD camera (ELMO) and a high-speed monochrome camera (Photron
FASTCAM-Net Max). The temperature of the samples was measured with a radiation thermometer (LumaSense Technologies
ImpacIN140/5-H). After the heating experiments, the samples were then buried in an epoxy resin and polished. The
microstructure was observed and chemical composition was determined using SEM/EDS (Hitachi S-3400N) and FESEM/EDS (JOEL JSM-7001F).
The experiment reproduced RP chondrules: radial pyroxene crystals growing from one or more points, mesostasis glass
filling in between the pyroxene crystals, and two types of metallic iron with different morphological characteristics. Pyroxene
crystals have dendritic shapes with linear surface contours, or are an aggregate of fine crystals similar to that in
cryptocrystalline chondrules, indicating rapid crystallization from a supercooled melt. The Mg# of the pyroxene crystals reflect
Mg/(Mg+Fe) ratios of the starting materials. Some samples have Fe-richovergrowth on large (> 1 μm) Mg-rich pyroxene crystals, suggesting that the
rapid crystal growth was followed by continued slow crystal growth due toslow cooling (1-10 °C/s).
The metallic iron in the samples was classified into two types basedon the texture: one was primary metal which is variable in size from µm tomm, crossing the radial pyroxene crystals. SEM observations showed that
relatively small (< 10 μm) primary metals are incorporated into the pyroxene
crystals and that radial crystals of pyroxene were aligned along the surfaceof the larger primary metals. The other was submicron-size metallic
inclusions (hereafter secondary metal) that occurred only in mesostasis glass(Fig.1). The secondary metal is spherical or dendritic in shape, sometimes
clinging to the surface of pyroxene crystals. In addition, they were found ina portion of the sample, not in the entire sample. Both primary andsecondary metals were produced by reduction of Fe oxides due to low
oxygen fugacity around the molten samples (Ar-H2 ambient gas), because no
metallic iron was added to the starting material. However, the timing offormation was different between the two inferred from their texture andFigure 1. (a) Back-scattered electron (BSE)
observation.
image of a RP chondrule produced by the
The primary metal was formed during total melting of the starting
experiment. Dendritic radial pyroxene crystals
material. We succeeded in-situ imaging of the formation of the primary
spread over the sample. (b) Enlargement view ofmetal using high-speed camera: the metal sphere forms in the melt when thethe white box in (a). The spherical secondary
sample was heated for about 10 or more seconds. In addition, the textural
metals are abundant in mesostasis glasses. Px;
observation indicates that the metal solidified in a silicate melt duringpyroxene and gl; glasses.
cooling, prior to the pyroxene crystallization. On the other hand, thesecondary metal is considered to have formed at temperature between the pyroxene crystallization and the glass transition(mesostasis glass formation). Secondary metal was observed in some samples cooled slowly (cooling rate is 1-10 °C/s) fromthe crystallization temperature to 500°C, while it was not observed in the glass of samples cooled rapidly after crystallizationof pyroxene. The secondary metal formation only by slow cooling is interpreted as the time required for the reduction reaction
and for the diffusion of Fe in the glass.
Similar primary type-metal inclusions are found in the natural RP chondrules, suggesting that the large metallic
spheres were formed immediately after total melting by the reduction of iron oxide during chondrule formation, or they were
present in the precursors. On the other hand, the metallic spheres of submicron size are universally found in natural RP
chondrules, and their microstructure is similar to that of secondary metal produced in this experiment. This indicates that RP
chondrules cooled at < 10 °C/s after crystallization of pyroxene and before glass solidification in a reduced condition to makesecondary metallic inclusions.
References[1] Villeneuve, J. et al. 2015. Geochim. Cosmochim. Acta 160:277. [2] Nagahara. H. 1981. Nature 292:135. [3] Nagashima. K
et al. 2006. Journal of Crystal Growth 293:193. [4] Dodd. R.T. 1973. Earth and Planetary Science Letters 40:71. [5]Nagahara. H. 1981. Memoirs of National Institute of Polar Research 20:145. [6] Kita. N.T. et al. 2010. Geochim. Cosmochim.
Acta 74:6610.

Curation Challenges Associated with the Apollo Next Generation Sample Analysis Program
Ryan A. Zeigler1, Juliane Gross1,2, Scott Eckley3,4, Andrea Mosie3, Charis Krysher3, Jeremy Kent3, Cecilia L. Amick3, Ernest
K. Lewis3, and Francis M. McCubbin1 and The ANGSA Science Team.
1
NASA Johnson Space Center, Houston, TX 77058, USA.
2
Rutgers State University of New Jersey, Department of Earth & Planetary Sciences, Piscataway, NJ 08854, USA,
3
Jacobs Technology, Johnson Space Center, Houston, TX
4Jackson School of Geosciences, University of Texas at Austin, Austin TX,
5
The ANGSA Science Team: https://www.lpi.usra.edu/%20ANGSA%20/teams/
Introduction and Overview
From 1969 to 1972, the Apollo missions collected 2196 individual samples of rock and regolith from the Moon (382 kg totalmass). Over the past 50 years, there have been over 3300 Apollo sample requests, utilizing >10,000 subsamples from 2190 of
the original 2196 samples. These myriad studies have shaped our understanding not only of the Earth-Moon system, but also of
the terrestrial planets, airless bodies like asteroids, the formation locations of the gas giants, and have even acted as a record of
the radiation history of our solar system as it has revolved around the galaxy for the past 4.6 Ga. Despite all of these studies
and all of this knowledge gained, there is still more to be learned from the Apollo samples. To this end, NASA solicited
proposals to study unopened or specially curated Apollo samples as part of the Apollo Next Generation Sample Analysis(ANGSA) Program. Prior to the ANGSA program being initiated there were six Apollo samples that had never been opened:(1) unsealed regolith drive tubes 73002 and 70012 (drive tubes are 35 cm long and 4 cm in diameter); (2) vacuum sealed
regolith drive tubes 69001 and 73001; (3) vacuum sealed bulk soil sample 15014; and (4) frozen basalt sample 71036.
Additionally, there were portions of other Apollo 17 regolith samples that have been stored frozen since shortly after they werereturned, as well as a suite of Apollo 15 sealed regolith samples (15012/15013) that were opened, processed, and continuously
stored since then in a He-purged environment (all other pristine Apollo samples are stored in N2-purged environments). Thesesamples were purposefully saved to be opened or studied at a future date where instrumentation had improved enough to givescientists the chance to maximize the scientific return on the samples.
NASA selected nine consortia of scientists to study a subset of the previously unexamined samples. The samples selected
were: unsealed drive tube 73002, sealed drive tube 73001 (part of a double drive tube pair with 73002), and a suite of frozen
samples including unexamined basalt sample 71036. These samples were selected for a variety of reasons, including: (1) The
73001/2 drive tubes were collected near Lara Crater at Station 3 in the Taurus Littrow Valley, and are spatially associated withboth landslides and a fault; (2) the sealed and cold samples have obvious ties to the upcoming Artemis missions; and (3) from apracticality standpoint, having an unsealed core that could be studied immediately (without having to extract the gas) would
allow for the program to start more quickly.
Curation Methodology
Each of the samples included in the ANGSA program had their own unique challenges during the curation process. Sample
73002 was the first drive tube sample to be opened in over 25 years. This meant that all of the equipment that was needed forthe extrusion and dissection process had to located, cleaned, assembled, and tested (including procurement of replacement
parts where needed). Similarly, the procedures for sample dissection had to be reviewed and modernized, which included
building a full-sized cabinet mock-up and extensive testing with analog samples. During the actual dissection process, several
non-standard dissection procedures were implemented such as time-sensitive sampling and mm-scale subsampling in the top
two intervals (top 1 cm). Multi spectral imaging was performed on the 73002 core [1] during processing, as well as on the
73001 core from outside the cabinet [2], as well as inside the cabinet (after dissection was complete [3]).
After dissection was complete, making continuous core thin sections required that the entire core vacuum impregnation andcuring devices had to be rebuilt. Additionally, a Keyance automated petrographic microscope was used to map all eight of the73002 continuous core thin sections at a resolution of a few microns per pixel (and will similarly be used when the 16 of the
73001 sections are complete). These maps were provided to the ANGSA science teams to serve as base maps for the electronand ion-beam work that would come later.

With sample 73001, the most obvious hurdles were related to how to get the gas out of the outer vacuum container (OVC) andCore Sample Vacuum Container (CSVC) prior to opening the samples. This involved building two bespoke pieces of hardware, a gas-extraction manifold built at Washington University in St. Louis [4] and a piercing tool built at ESA [5], as well as
the actual assembly, integration, and operation of this equipment within the materials constrained environment of the JSC
clean rooms.
The ability to process frozen samples at -20°C was not a capability that existed at JSC prior to ANGSA, and an existing Apollo
glovebox had to be retrofit to work at those temperatures. Significant facility modifications to the walk-in freezer in the JSC
Experimental Impact Lab to make it material and environmentally compliant with processing of Apollo samples was also
required [6]. Similarly, the procedures for how to process the samples under these extreme conditions had to be developed andimplemented [7].
This was the first time that X-ray Computed Tomography (XCT) was used as part of the curation process for drive tube
dissection. Whole-core scans were made of both 73002 and 73001 prior to extrusion and dissection at the University of Texas
High-Resolution X-ray Computed Tomography (UTCT) Facility for high-resolution scanning (Figure 1). Both of these scans
had unique challenges that were overcome to give excellent data sets that proved invaluable to both the curation and mission
science teams [8]. Over 350 particles in the 4-10 mm and >10 mm size particle size fractions were separated during dissection,individually bagged in Teflon (3 bags), and scanned by XCT at NASA JSC [9]. These scans allowed for the identification ofdifferent lithologies within the particles (Figure 1), which greatly helped with the request and allocation process [10].
Summary
The ANGSA program was designed to help us prepare for the upcoming Artemis missions, while at the same time getting
important new scientific results from the Apollo samples. Each of the samples included in the ANGSA program had their own
unique challenges related to the curation process, and the work on this program has greatly enhanced our readiness for the next
batch(es) of lunar samples to come back.
References[1] Sun et al. (2021) MAPS, https://doi.org/10.1111/maps.13715. [2] Sun et al. (2022) A17-ANGSA Workshop, #2021. [3]Lucey et al. (2022) A17-ANGSA Workshop, #2017. [4] Parai R. et al. (2021) LPSC 52, #2665. [5] McDonald F. et al. (2022)
EPSC2022, #1117. [6] Amick C. et al. (2020) LPSC 51, #1632. [7] Kent J. J. et al. (2022) Metsoc 85, #6497. [8] Ketcham R.
A. et al. (2022), A17-ANGSA Workshop, #2044. [9] Zeigler R. A. et al. (2021) LPSC 52, #2632. [10] Shearer C. K. et al.
(2022), A17-ANGSA Workshop, #2003.

Figure 1. X-ray Computed tomography images of the entire 35 cm long 73001 core (top image), as well as individual soil particles sieved
from the 73001 and 73002 cores representing a variety of lithologies observed.

Sample Return and Preliminary Examination Processes for the OSIRIS-REx Mission
Anjani T. Polit1, Harold C. Connolly Jr1,2, Dante S. Lauretta1, and the OSIRIS-REx Sample Analysis Team
1
Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona, USA
2
Rowan University, Glassboro, NJ, USA
The OSIRIS-REx spacecraft collected a sample of asteroid (101955) Bennu on October 20, 2020 [1, 2] and departed
the asteroid in May 2021. On September 24, 2023, the spacecraft will fly by Earth and release the Sample Return Capsule(SRC), which will land four hours later in the desert of the U.S. state of Utah. Once the SRC is located within the landing
ellipse, the OSIRIS-REx recovery team will be flown via helicopter to retrieve the SRC and take it to a temporary cleanroom
for initial processing. In the cleanroom, the SRC will be opened, a high-purity nitrogen purge will be established, and thesample canister assembly will be packed for transport to the OSIRIS-REx curation facility at NASA’s Johnson Space Center(JSC).
The Preliminary Examination (PE) period for sample analysis begins once the sample canister is opened at JSC. The
focus during this time will be on disassembly of the sample canister, initial documentation of the sample, production of asample catalog (to be completed within six months of Earth return), splits of sample for international partners, and the initial
allocation of sample to the Sample Analysis Team (SAT). Within approximately one week after sample return, a Quick Look
Tiger Team of the SAT will conduct a very preliminary characterization using a small amount of sample collected from theoutside of the sample acquisition mechanism. Armed with information from the Quick Look sample analysis, the SAT willthen focus on identification of distinct lithologies within the bulk sample using the mission imaging system known as QRIS
(Quantitative Reflectance Imaging System), visual inspection, density calculations, and initial analysis on bulk oxygen isotope
abundances as well as H, N, and C to enable decisions on which particles will be allocated to each planned science
investigation. While the bulk sample is being processed for analysis, contact pads from the sample acquisition mechanism will
also be processed.
The OSIRIS-REx team is preparing for sample return, recovery, and analysis with a series of reviews, team training
activities, and readiness tests scheduled over the next year. The SAT is currently conducting a Sample Analysis Readiness Test
(SART) which will conclude by June 2023, during which the SAT is demonstrating certification in key areas necessary forsample analysis. The SART is providing valuable lessons for revision of the mission Sample Analysis Plan (SAP) and is
helping the team prepare for our July 2023 sample analysis readiness review. The SAT also completed two Sample Analysis
Science Operational Proficiency Integrated Exercises (SA-SOPIEs), with a third scheduled in early 2023. These exercises use
analog sample material to test instrumentation, initial sample characterization, and the selection of particles the SAT will use toaddress early mission science and the hypotheses outlined in the SAP.
References[1] Lauretta, D.S. et al. 2021. In Sample Return Missions, Longobardo, A., ed. (Elsevier), pp. 163–194. [2] Lauretta, D.S. et al.
2022. Science Vol 377 pp. 285-291.

Coordinated Thermal and Physical Analysis of OSIRIS-REx Samples of Asteroid Bennu
Andrew Ryan1 and the OSIRIS-REx Sample Analysis Team
1
University of Arizona, Tucson, Arizona, USA
Remote sensing and sample analysis both provide insight into the thermal and physical properties — and thereby the origin andevolution — of asteroidal material. Remote determination of thermal properties can be used to infer the physical characteristics
of boulders and regolith on asteroid surfaces and to predict the evolution of an asteroid’s orbit due to the Yarkovsky effect.
Analysis of returned particles and particle assemblages informs the interpretation of remote sensing data and can powerfully
constrain models of dynamic events such as robotic sampling and impacts at different scales.
It is well-known that the strength of stony material obeys scaling laws, such that larger boulders (or bodies) are weaker
than smaller ones and thus are more susceptible to collisional damage. It is also likely (but not yet as widely recognized) that
thermal properties of boulder materials may depend on the size of the sample and/or the length scale of the remote sensing
observations. Therefore, to link the properties of returned samples and relevant meteorite analogs to remote sensing data ofasteroid surfaces, a coordinated physical and thermal sample analysis campaign with measurements across multiple length scales
is necessary.
Below (Figure 1) is a summary of the physical and thermal measurements that are planned for the returned samples
from Bennu. In addition to addressing specific hypotheses related to the formation and evolution of Bennu’s boulders and fineregolith, we seek to collect coordinated sample data that can contribute to the development of a broadly applicable multi-scale
thermal and mechanical model for primitive rubble-pile asteroids.

Figure 1. Planned OSIRIS-REx sample measurements (green) feeding into a multi-scale model for regolith, boulder, andasteroid thermophysical properties (blue).

Contamination monitoring of the OSIRIS-REx ISO5 asteroid sample cleanroom
K. Righter1, N.G. Lunning1, K. Allums2, M. Calaway2, M. Rodriguez2, R. Funk2, L. Yan2, T. Cala2, J. McQuillan2, A. Regberg1,
R. Davis2, E.L. Berger1,2, A. Burton1, A. DeCuba2, J. Ponce2
1
Astromaterials Curation, NASA Johnson Space Center, 2101 NASA Pkwy, Houston, TX 77058 USA
2Jacobs/JETS, Astromaterials Curation, NASA Johnson Space Center, 2101 NASA Pkwy, Houston, TX 77058 USA
The OSIRIS-REx mission to asteroid Bennu successfully collected hundreds of grams of asteroid regolith in October 2020 [1].
The spacecraft departed Bennu in May 2021 for Earth return and will release the sample canister to be recovered in Utah in
September 2023 [2]. Samples will be transported to the curation facility at NASA Johnson Space Center, where an ISO5
equivalent cleanroom has been designed in 2017 and completed in 2021. Aspects of the design and material selection for thecleanroom and its supporting facilities (air handling system, cleanroom floors and walls, filters, paints, etc.) were optimized tominimize effects of organic and inorganic contaminants and offgassing [3]. Since its completion, the lab has been carefully
monitored to understand and establish a baseline with respect to multiple environmental aspects – measurement of particle
counts, deploying Si wafer witness plates for organic and inorganic contaminants, deploying aluminum foils for a focus onorganics with JSC in-house expertise, gas samples, and regular microbial and fungal measurements on selected surfaces and air
samples in the cleanroom. This contribution will report on nearly one year of monitoring and highlight several specificaspects that have led to a better understanding of the new cleanroom environment.
Particle counts: particle counts are taken weekly in 6 different locations in the cleanroom, in high traffic and low
traffic areas and distributed representatively throughout the lab. The particle counts have remained well within the ISO5
rating of the cleanroom and have only exhibited higher counts (but still well within the ISO5 limits) in cases where there has
been unusual activity. One such example is the repair of fan filter units (FFUs) in September 2022. Careful coordination ofparticle count measurements during servicing of the FFUs led to a better understanding of how the counts are affected whenceiling tiles were removed and FFUs were adjusted, as well as providing baseline information on how quickly the cleanroom
environment is restored to background levels after the cease of repair activities. Monitoring of such off nominal events will bedone in the future as opportunities arise.
Si wafer witness plates (Balazs, Inc): Large area Si witness plates have been deployed several times over this period,
with the goal of detecting possible organic and inorganic contaminants. For inorganic and organics, 8-inch polishedsemiconductor silicon witness wafers were exposed to the laboratory air for 24 hours each. After exposure, the witness platefor organics was sent to Balazs for Thermal Desorption Gas Chromatography Mass Spectroscopy (TD-GC-MS), yielding
results for organic compounds from C6 to C28 (with limit of 0.1 ng/cm2). The wafer for inorganics was analyzed by vapor
phase decomposition inductively coupled plasma mass spectrometry (VPD-ICP-MS) which yielded data for 35 elements ofinterest (Al, As, B, Ba, Be, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Ge, Hf, In, K, La, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Sn, Sr, Ta, Ti,
W, V, Y, Zn, and Zr). Analyses for organics have yielded very low concentrations in general – lower than similar monitoringof the ISO4 equivalent Genesis lab, for example across a decade of monitoring. The few and very low species detected inearly testing included TXIB (a plasticizer used in urethane elastomers and PVC piping), triacetin (a common plasticizer andsolvent, 2-(2-butoxyethoxy) ethanol and texanol (used as a solvent for and in paints). These species have not been detected inmeasurementsts made in late 2022. Analyses for inorganics that were above detection limits included Al (from wall andceiling struts), B (from the borosilicate glass in the Fan Filter Unit (FFU) ULPA filters), Cu, Sn, and Zn (could be fromelectrical or electrical conduit), and Fe (could be from stainless steel or electrical conduit). Continued monitoring of theseelements will allow identification of problematic sources, but the levels detected are lower than other NASA curation labs,
which is a testament to the careful selection of materials during the design and construction phase.
Gas sampling (Balazs and JSC): Cleanroom air samples were analyzed using two different approaches. Volatileorganics in air were sampled with an adsorbent tube connected to a pump (100 mL/min.) for 6 hours. After exposure, theadsorbent tube was sent to Balazs for TD-GC-MS analyses for a wide range of hydrocarbons and volatile organic compounds(limit of 0.1 ng/L). A NASA-JSC based collection of 450 ml gas samples was followed by GC-MS. Both approaches havedemonstrated very low levels of organics in general, with most species either (a) below detection limits, or (b) expected but
present at very low levels (e.g., isopropanol, toluene, and xylene).

Al foils deployment: In addition to the Si wafers deployed for analysis by Balazs, the curation staff has also deployedmonthly sets of aluminum foil witnesses that are being archived. These will also be analyzed using JSC in-house analyticaltechniques for amino acids. Results are not yet available at the time of writing of this abstract.
Microbial and fungal monitoring: Terrestrial contamination of asteroid or meteorite samples can lead to biologicaldegradation, something we wish to avoid during short- and long-term curation. Swabs and sampling for microbial and fungal
analysis have been collected regularly on various surfaces within the OSIRIS-REx cleanroom (as well as many other JSC
cleanrooms [4]). Microbiological air samples were also collected by passing air through an electret filter at 200 L/min.
Results of these analyses show very low levels in general, and decrease with time in any given area. When rates become moreelevated, special cleaning procedures involving hydrogen peroxide have been developed to lower the fungal and microbial
recovery rates.
Having the cleanroom completed more than a year in advance of sample return has allowed many important kinds ofmonitoring to be undertaken, lab environments characterized, and baseline established for any expected or unexpectedcontaminants. Future emphasis will be on maintaining the monitoring during outfitting of the lab (see details in [5]), as wellas the presence of human processors in the lab for longer durations.
References[1] Lauretta, D.S., et al. (2022) Science 377(6603), 285-291; [2] Lauretta, D.S., et al. (2017) Space Science Reviews 212, 925984; [3] Calaway, M.J. and McQuillan, J. (2022) LPI Contributions, 2678, abstract #1148; [4] Regberg, A.B., et al. (2022) LPI
Contributions, 2678, abstract #1686; [5] N. Lunning et al. (2022) this symposium.

A study of the curation protocol by sample analysis working team (SAWT)in Martian Moons eXploration (MMX) project*R. Fukai1, T. Usui2, W. Fujiya3, Y. Takano4, K. Bajo5, A. Beck6, E. Bonato7, N. L. Chabot8, Y. Furukawa9, H. Genda10, M.
Koike11, M. Matsuoka12, Y. N. Miura2, F. Moynier13, S. S. Russell14, M. E. Zolensky15, H. Sugahara1, S. Tachibana1,2, K.
Sakamoto1, and M. Abe1
12
Japan Aerospace Exploration Agency, The University of Tokyo, 3Ibaraki University, 4Japan Agency for Marine-Earth Scienceand Technology, 5Hokkaido University, 6Marietta College, 7German Aerospace Center, 8Johns Hopkins University, 9Tohoku
University, 10Tokyo Tech, 11Hiroshima University, 12National Institute of Advanced Industrial Science and Technology, 13Institut
de physique du globe de Paris, 14Natural History Museum, 15National Aeronautics and Space Administration
Japan Aerospace Exploration Agency (JAXA) will launch a spacecraft in 2024 for a sample return mission from Phobos(Martian Moons eXploration: MMX). The major scientific goals of MMX are to constrain (1) the origin of Phobos and Deimosand (2) the evolution of the Mars-moon system [1]. The touchdown operations are planned to be performed twice at different
landing sites on the Phobos surface to collect > 10 g of the surface materials [2]. After the return to the Earth, the Phobos
samples will be collected from the individual sample canisters and introduced to the clean chamber installed at ISAS (Instituteof Space and Astronautical Science). The Sample Analysis Working Team (SAWT) of MMX designed the procedure of
Phobos sample analysis mainly conducted by the initial analysis teams [3]. For the next step, the SAWT will define theprocedure of the curation process (mostly non-destructive analysis) of the Phobos samples, which will be presented here.
The protocols of the Phobos sample curation are illustrated in figure 1. First, the headspace gas from the sample
container will be collected during the Quick Analysis phase. The Quick Analysis will be operated by the sampler and curation
teams in ISAS/JAXA. The terrestrial leak and contamination from the sampling systems will be tested using a quadrupole
mass spectrometer equipped with a gas sampling system. Second, the bulk Phobos sample will be observed in the cleanchamber under purified-N2 gas with an ambient condition (Pre-basic Characterization) within three weeks. This phase will be
operated by the curation team in ISAS/JAXA and the instrument team of the MMX mission. The consistency between the datafrom the instruments in the clean chamber and the spacecraft will then be evaluated.
Subsequently, the curation will distribute the small amount of Phobos samples to the Initial analysis team of MMX to
conduct the "Preliminary Examination". The objectives of the preliminary examination are to provide (1) feedback on thesubsequent sample allocation process, (2) preliminary scientific results that will address parts of MMX mission goals, and (3)evaluation of the sampling system and terrestrial alteration on Phobos samples. Because multiple models are proposed for theorigin of Phobos [1] (e.g., giant impact, the capture of asteroids), the chemical and mineralogical characteristics of Phobos
must be assessed before the allocation of the samples to the individual Initial Analysis teams. The Preliminary Examination
will start after about 1 month from the sample return. Simultaneously, the curation team in JAXA will observe the individual
grains and aliquots of the samples in the clean chamber (Basic Characterization). The results obtained in Preliminary
Examination will be investigated with several SSTs (Science Strategy Teams). Based on the results, the curation team will
decide on the sample amounts to allocate to the Initial Analysis team. After 6 months from the Preliminary Examination, Initial
Analysis will be started to perform the comprehensive analysis for Phobos samples within 1 year.
The curation protocols the SAWT proposes here are partly based on those in Hayabusa & Hayabusa2 missions [4].
However, our strategy enables us to utilize larger amounts of return samples compared to the previous sample return missions.
Also, the chemical/mineralogical characteristics of Phobos will be quickly understood throughout the non-destructive anddestructive analyses in the curation process.

Fig. 1: Curation protocols for the Phobos samples.

References: [1] K. Kuramoto et al. (2022) Earth, Planets, and Space, 74 (12). [2] T. Usui et al. (2020) Space Science Review,
216 (49). [3] W. Fujiya et al. (2021) Earth, Planets and Space, 73 (120). [4] T. Yada et al. (2022) Nature Astronomy, 6, 214.

Bridging the gap - linking remote sensing, in-situ and laboratory spectroscopy
Maturilli A.1, Schwinger S.2, Bonato E.1, Hamm M.2, Baque M.1, Helbert J.1, Alemanno G.1, D’Amore M.1
1
Department of Planetary Laboratories, Institute for Planetary Research, DLR, Berlin
2
Department of Planetary Physics, Institute for Planetary Research, DLR, Berlin
Sample return provides us with “ground truth” about the visited body, verifying and validating conclusions that can be drawn by
remote sensing (both Earth-based and by spacecraft) and via landed instruments on other bodies. The detailed investigation of
the mineralogy and geochemistry of Ryugu plays a fundamental role in the understanding of its formation processes, and thereby
gather further knowledge about the building blocks of the solar system. Based on the preliminary data from remote sensing
measurements and laboratory-based measurements, Ryugu is rich in hydrated carbonaceous chondrite (CC) like material andmore specifically it is very similar to Ivuna-like (CI) carbonaceous chondrites [1]. These meteorites are characterized by a highabundance of phyllosilicates and organic matter [2], which makes them have a low albedo. However, Ryugu seems to be evendarker than CIs, as well as being more porous and fragile [1].
Back in August 2022, the Institute of Planetary Research at DLR (Berlin) received a fragment retrieved by the Hayabusa2 mission
from asteroid Ryugu. The fragment assigned to us for analyses is sample A0112, from chamber A. Our investigation is based on
two main goals. The first goal is to address a fundamental challenge in the interpretation of remote sensing data which was seen
during the initial analysis of the Hayabusa 2 samples. Observations of planetary surfaces using spectroscopy have shown subdued
contrast compared to measurements performed under laboratory conditions on analog materials. A strong focus of the work
performed at PSL over the last decade has been to understand - and if possible minimize – the difference between laboratory andremote sensing observations (e.g. [3, 4, 5, 6]). Simulating the conditions on the target body as well as accurately reproducing theobserving geometries have gone a long way towards that goal, however differences remain. A suggested explanation is thedifference between terrestrial analog materials including even meteorites and the surfaces of planetary bodies. With Ryugu
samples this hypothesis can be tested further, leading to a deeper understanding of the link between laboratory and remote sensing
observations and thus benefiting not only the analysis of Hayabusa 2 data but of all remote sensing observations of planetary
surfaces using spectroscopy. The second goal building on this is an investigation of the mineralogy and organic matter of thesamples collected by Hayabusa 2, to better: a) understand the evolution of the materials characterizing asteroid Ryugu andtherefore advance our knowledge of the mineralogy of the protoplanetary disk and organic matter (OM); b) investigate theaqueous alteration that took place in the parent body that lead to its current chemical and mineralogical characteristics; c) compare
the results with data collected from pristine carbonaceous chondrite meteorites rich in hydrated minerals and organic matter.
We are currently collecting the first datasets, and for doing so we are applying a strict protocol to maintain the grain as pristine
as possible. The first set of measurements is taking place keeping the sample within the N2 filled sample holder it was delivered
in. Just afterwards, we will open the protective holder to transfer the sample in the anaerobe bench to the Hayabusa1 holder (thatwe hosted in our institute too) and we will repeat those measurements. As a final step, we will remove the sample from thisholder and let the sample be in contact with laboratory
atmosphere.
Here is a description of the protocol:
1. The first step of our investigation consists in 3D
imaging of the sample (Figure 1) with the use of a
Keyence VHX-7000 4K High Accuracy digital
microscope;
2. Mapping of the sample with Raman spectroscopy(Figure 2);
3. Mapping of the sample with IR microscope in the
wavelength range 0.25 – 25 µm;
4. Collection of reflectance data in the wavelength
range 0.25 – 25 µm;

Figure 1: 3D scan of particle A0112 with a Keyence VHX-7000 4K
High Accuracy digital microscope.

A

B

Raman intensity (arbitrary units)

5. Transfer of the sample to a
dedicated holder previously
created for the analysis of
Hayabusa1
samplesandrepetition of the previous steps;
6. Sample open and exposed to air:storedindrycabinets,
spectroscopy measured
invacuum;
7. 3D imaging with the use of a
Keyence VHX-7000 4K HighAccuracy digital microscope
8. IR data collection in the
wavelength range 0.25 – 25 µm
9. Raman mapping: in this caseafter the acquisition of IR data tominimize the reaction of organic
matter with the laser;
10. SEM and EDX mapping at low
voltage of uncoated andunprepared sample.

Wavenumber(cm-1)

Figure 2: Raman preliminary results. A. WITec Alpha 300 confocal microscope setup
with JAXA’s sample holder containing particle A0112. B. Typical Raman spectra ofpolyaromatic carbonaceous matter measured under N2 atmosphere in the unopened
container showing typical D and G carbon bands and fitted with a Lorentz function to
extract parameters such as bands’ position, full width at half maximum (FWHM), andbands’ intensities. Inlet: measurement points on particle’s surface.

Up to now, step 1 has been successfully executed as can be seen in Figure 1. The 3D measurements will help planning the next
steps of the measurements. They are also an interesting result in itself as they will allow to determine the volume and thereby
the density of this particle.
Step 2 has been started and Raman spectra were successfully acquired on the particle without opening the original container (aswas executed for Hayabusa1 particles previously). Preliminary data show the typical carbonaceous matter signature typical of
CCs from which their thermal history can be derived [8].

References[1] Yada T., et al., 2022. Nat Astron 6, 214–220. [2] Cloutis E. A., et al., 2011. Icarus, 212:1. [3] Maturilli A., et al., 2016a.
Earth, Planets and Space 68(1). [4] Maturilli A., et al., 2016b. Earth, Planets and Space 68(1). [5] Beck P., et al., 2018. Icarus
313: 124-13. [6] Yesiltas M. et al., 2020. Meteoritics & Planetary Science, 55(11): 2404–2421. [7] Ray D. and Shukla A.D.,
2018. PSS 151, 149-154. [8] Bonal L. et al., 2016. Geochimical et Cosmochimica Acta, 189:312-337.

An infrared look at Ryugu returned samples in the meteorite/asteroid perspective
R. Brunetto1, A. Aléon-Toppani1, T. Nakamura2, C. Lantz1, Z. Dionnet1, F. Borondics3, D. Baklouti1, Z. Djouadi1, S. Rubino1,
K. Amano2, M. Matsumoto2, Y. Fujioka2, Y. Fukuda2, T. Morita2, M. Kikuiri2, E. Kagawa2, R. Milliken4, M. Matsuoka5, H.
Yurimoto6, T. Noguchi7, R. Okazaki7, H. Yabuta8, H. Naraoka7, K. Sakamoto9, S. Tachibana9-10, S. Watanabe11, Y. Tsuda9 andthe Hayabusa2-initial-analysis Stone team.
1IAS, Université Paris-Saclay, CNRS, France, 2Tohoku University, Japan, 3SMIS-SOLEIL, France, 4Brown University, USA,
5LESIA, Observatoire de Paris-Meudon, France, 6Hokkaido University, Japan, 7Kyushu University, Japan, 8Hiroshima

University, Japan, 9ISAS/JAXA, Japan, 10The University of Tokyo, Japan, 11Nagoya University, Japan
Laboratory analyses of materials originating from asteroids give us the opportunity to directly study the components thatformed in the protoplanetary disk. However, collections of extraterrestrial materials available on Earth have strong biases, andthe link between laboratory samples and their asteroidal parent bodies is often ambiguous. Furthermore, many classes of small
bodies are likely absent from our collections [1]. Some of these limitations are overcome by sample return missions, such as
Hayabusa2/JAXA that targeted and sampled the small and dark near-Earth asteroid Ryugu [2]. Ryugu has retained valuable
information on the formation and evolution of planetesimals at different epochs of our Solar System history [3].
Samples originating from asteroids can be analyzed thanks to modern analytical techniques [4]. Among them, infrared
spectroscopy is important for comparing lab measurements to remote sensing observations of small bodies. In addition, midand far-infrared (MIR, FIR) reflectance spectra of asteroids and meteorites contain fundamental vibrational bands which are
diagnostic of their mineral and organic compositions. Infrared spectra of Ryugu were measured by NIRS3 on board Hayabusa2
in the near-IR range [5], however the MIR-FIR range was not available. The return of Ryugu samples collected by Hayabusa2
provide an excellent opportunity to measure the MIR-FIR spectra of Ryugu materials and to compare them with similar
observations of meteorites and asteroid, in particular the remote sensing MIR-FIR spectra of B-type asteroid Bennu acquiredby the OSIRIS-REx mission [6].
In this study we report IR reflectance measurements of two mm-sized Ryugu stones (A0026 and C0002), acquired at the SMIS
beamline of synchrotron SOLEIL (France) and at Tohoku University (Japan), and we compare them with meteorite spectra
acquired with similar setups, and with the available remote sensing spectra of different asteroids.
Generally speaking, the MIR and FIR reflectance spectra of the two Ryugu stones show similitudes with spectra of CI
meteorites, both in terms of overall spectral shape and in terms of peak position of the main reststrahlen silicate features,
although some differences are observed probably due to a different history of alteration (both in space and on Earth). The IR
spectra of Ryugu samples are clearly different from those of CM meteorites and other ungrouped primitive meteorites. They
also differ from the remote sensing spectrum of asteroid Bennu. Overall, the results indicate that Ryugu has both a mineralcomposition and a history of aqueous alteration that are more similar to those of CI chondrites than to those of CM chondrites
and of asteroid Bennu. These observations confirm that Ryugu and Bennu, two small near-Earth asteroids that are so similar inmany ways (size, morphology, density, etc.), have distinct IR spectra also in the mid-IR and far-IR, in agreement to what waspreviously shown in the near-IR range from orbital data [5,6].
Finally, the presence of different lithologies in C0002 [3] allows to trace the early evolution of Ryugu materials and thecorresponding IR spectral variations. The parameters extracted from the micro-IR spectra of different clasts in C0002 draw analteration pattern which is different from that of CM meteorites [7,8], and which helps to reconsider the general asteroidmeteorite connection in a different perspective.
References[1] Greenwood R.C. et al. 2020. Geochimica et Cosmochimica Acta 277, 377–406. [2] Watanabe S. et al. 2019. Science 364,
268–272. [3] Nakamura T. et al. 2022. Science 10.1126/science.abn8671. [4] Brunetto R. et al. 2021. In: Sample Return
Missions: The Last Frontier of Solar System Exploration. Editor: Andrea Longobardo. Elsevier 315–342. [5] Kitazato K. et al.
2019. Science 364, 272–275. [6] Hamilton V. et al. 2019. Nature Astronomy 3, 332-340. [7] Hanna R.D. et al. 2020. Icarus
346. [8] Dionnet Z. et al. 2022. Meteoritics and Planetary Science 57, 965–988.

P-rich compounds within the Ryugu sample collection: a perspective from joint
MicrOmega/Curation, the OU and Phase2 Kochi curation activities
1,2

Pilorget, C.; 1Loizeau, D.; 3Ito, M., 1Bibring, J.-P.; 1Carter, J.; 1Le Pivert-Jolivet, T.; 1,4Riu, L.; 1Brunetto, R.; 3Tomioka, N.;
5
Uesugi, M.; 6Yamaguchi, A.; 6Imae, N.; 7,8Hatakeda, K.; 7Yogata, K; Y.; 1Baklouti, D.; 7,9Okada, T.; 7Yada, T.; 7,9Usui,T.;10Greenwood, R.; 11Liu, M., and the Ph2K team, the OU team and the MicrOmega Curation Team.
1

IAS, Université Paris-Saclay, CNRS, France, 2Institut Universitaire de France, 3JAMSTEC, Kochi Inst. Core Sample
Research, 4ESAC, ESA, Madrid, Spain, 5JASRI, 6National Institute of Polar Research, 7Institute of Space and Astronautical
Science, Japan Aerospace Exploration Agency, 8Marine Works Japan, Ltd, 9University of Tokyo, Bunkyo, Tokyo 113-0033,
Japan, 10Open U. UK, 11UCLA US
The JAXA Hayabusa2 mission has returned for the first time samples collected at the surface of a C-type asteroid, Ryugu[1,2]. They are now preserved at the Extraterrestrial Samples Curation Center of JAXA at ISAS in Sagamihara, Japan, where
they are submitted to a first round of non-destructive and non-invasive analyses, while maintained in a purely non-altering
environment since their collection [3]. Some of these grains have also been extracted to be further analyzed by - initially - 8
analytical teams, including Phase2 Kochi (Ph2K) curation [4,5], and later open to AOs.
The MicrOmega hyperspectral microscope operating in the near-infrared (NIR) range (0.99 – 3.65 µm) is performing themineralogical and molecular characterization of the samples present in the Curation Center, down to the scale of a few tens of
micrometers [6]. By the end of September 2022, >375 individual grains (a few mm in diameter) and 25 sub-bulks (a few tensof mg each) have been analyzed with MicrOmega, in addition to the 6 initial bulks from chamber A and C. It offers a global
view on the Ryugu samples, preserved from any terrestrial contamination, and can be used to target specific grains and areas ofinterest with complementary techniques. In particular, while strong features at 2.7 µm – translating their OH-rich content - and3.4 µm – diagnostic of the presence of organics – dominate at a global scale, key distinctive signatures have been identified at
sub-mm scale [7,8,9,10]. Here we present the international collaborative curation work conducted with the Ph2K and the OU
on Ryugu samples and focused on the P-rich compounds.
Specific grains of interest/inclusions have been identified with MicrOmega within the Curation Facility, for having a brightaspect (reflectance of ~10-20%) coupled to a very peculiar spectrum in the NIR: a broad and deep band at ~3 µm, withadditional features, in particular a sharp band at ~2.7 µm shifted by ~10 nm compared to the one observed in the matrix [7].
Grains with such properties tend to occur as inclusions or loose grains with sizes up to a few hundreds of microns, similar tocarbonates observed by MicrOmega [8] but with a much lower occurrence. Such signatures have been identified in the C0209
sub-bulk delivered to the Ph2K team in April 2022. Grains presenting these properties have been manually extracted andanalyzed by SR-XRD at Spring-8 and then combined SEM/EDX at Kochi JAMSTEC, which revealed an enrichment in P, O
and Mg elements, possibly pointing towards Mg-phosphates as suggested by other observations on a few samples [11,12].
These grains and the C0209 sub-bulk were then re-analyzed by a MicrOmega unit present at IAS [13]. The results confirmed
the correlation between the IR signature and the P, O, Mg content detected by the EDX. Slight modifications of the IR spectrain the 2.7-3.0 µm range points towards a contact with the terrestrial atmosphere after the extraction of the grains from theCuration Center.
These results offer a new perspective on the characterization of the distribution and properties of such compounds over theentire collection. Further analysis of the grains is on-going to assess the possible couplings of the P-rich phases with othercompounds (minerals and/or organics) and their origin by H, O isotopic ratios.
References[1] Watanabe et al. (2019) Science 364 268-272. [2] Morota et al. (2020) Science 368 654-659. [3] Yada et al. (2022) Nat
Astron, 6, 214-220. [4] Ito et al. (2022) Nat Astron, [5] Liu et al. (2022) Nat Astron, [6] Bibring et al. (2017) Space Sci. Rev.
208, 401-412. [7] Pilorget et al. (2022) Nat Astron, 6, 221-225. [8] Loizeau et al. (2022) 53rd LPSC contrib. N°2017 [9] Carter
et al. (2022) 53rd LPSC contrib. N°1495. [10] Bibring et al. (2022) this conference. [11] Nakamura et al. (2022) Proceedingsof the Japan Academy, Series B 98, 227–282. [12] Ma et al. (2022) MetSoc contrib. N°2695. [13] Loizeau et al. (2020)
Planetary and Space Science 193 article id. 105087.

Overviews of the Hayabusa2 mission and its integrated science
Sei-ichiro Watanabe1, Hayabusa2 Science Team, Hayabusa2 Curation Team, and Haybusa2 Initial Analysis Team1
Nagoya University
The asteroid explorer Hayabusa2 performed its proximity operation around Cb-type asteroid (162173) Ryugu from
June 2018 to November 2019, and returned to Earth with the surface sample in December 2020. More than 5 g of the particles
in the sample catchers were successfully retrieved and the initial description and initial analysis were performed. The
formation of the Solar System and the subsequent history of asteroid Ryugu will be discussed based on the proximity
observations of Ryugu and analysis of the return sample.
From the initial analysis, the Ryugu sample was confirmed to be similar to CI (Ivuna-type) chondrites in terms ofmineral assemblages and composition, and isotopic ratios [1–4]. Some differences were attributed to the effects of weatheringand contamination on the ground suffered by CI chondrites, so that the Ryugu sample is considered to preserve the chemical
and isotopic state of CI chondrites as they were in space. The presence of grains having large anomalies in the stable isotope
ratios of H, C, and N was confirmed [5], suggesting that these particles were produced in the low-T environment of the solar
parental molecular cloud and retained without undergoing isotopic equilibrium on the parent body. The organic carbon of the
Ryugu sample is comparable to that of CI chondrites, whereas the carbonate content is significantly higher, and therefore thetotal carbon content is somewhat higher. The presence of CO2-bearing aqueous fluid inclusions in a large iron sulfide(phyrrhotite) crystal [3], the IR absorption of NH in ammonium salts or organic nitrogen compounds [6], and the very low
content of chondrules and CAIs [3] suggest that the parent body of Ryugu may have originated outside the snow lines of CO2
and NH3 (presumably outside Saturn's orbit). Near infrared spectrometer NIRS3 found a global 2.72 μm absorption on Ryugu,
indicating omnipresence of Mg-rich phyllosilicates [7]. Return sample analyses clarified that aqueous alteration in the parent
body had progressed in alkaline water with a temperature of ~310 K [1] generated by the decay heat of 26Al in the interior ofan about 100-km sized icy body at 5-6 million years after the formation of CAIs in the protosolar disk [3]. The presence of lessaltered grains in Ryugu particles suggests the difference in temperature between the near-surface and interior of the icy parent
body at the stage of aqueous alteration [3]. Some of these less altered grains have particularly high micro-porosity, suggesting
the formation of planetesimals from fluffy ice and stone particles. It is noteworthy that franboidal magnetite grains with aremanent magnetization of ~100 μT were found in several Ryugu particles [3], suggesting that the parent body had moved
from the outer Solar System to the asteroid belt, where disk magnetic field is expected to have been strong enough,before/during a period of aqueous alteration.
These results are consistent with the scenario that carbonaceous chondrites’ parent bodies are icy planetesimals withdiameters of ~100 km that formed in the outer Solar System and were brought to the inner Solar System through scattering by
giant planets. However, based on the reflection spectra and orbital analysis of Ryugu, its parent body is considered to be one of
the collisional families in the inner asteroid belt [8]. Therefore, it is necessary to verify whether the scattering by giant planets
could bring planetesimals to such an inner region of the asteroid belt. In any case, it is a great discovery that the parent bodies(at least one of them) of CI chondrites are collisional families in the inner asteroid belt.
Contrary to the parent body processes, the sample analysis information about the formation and evolution of Ryugu
itself is rather little and the results from remote sensing observations are important. Low bulk density and abundant large
boulders indicate that Ryugu is a rubble-pile object formed through re-accumulation of fragments produced by catastrophic
disruption or cratering of the parent body [9]. Surface mean visible spectrum of Ryugu is similar to that of (495) Eulalia, andspectrum of the largest boulder Otohime is similar to (142) Polana, both asteroids are the largest members of the PolanaEulalia collisional families. Assuming the collision frequency model for the asteroid main belt, the surface age of Ryugu is
about 10 Myr based on crater chronology using crater-to-impactor size ratio of 130 after the SCI experiment [10]. The surface
age is much younger than the estimated ages of the parent collisional family of Ryugu, either the Polana or Eulalia family.
Thus, the surface age is considered to correspond to the top shape formation, probably global resurfacing events [9, 11],
induced by the YORP spin-up long after the formation of Ryugu.
Much has also been learned about the post-formation history of Ryugu. From the analysis of the YORP effect using
the shape models, Ryugu is now slowly spinning down and had a fast rotation in the past (~10 Ma) [12]. The analysis of the tilt
angle distribution on the surface of Ryugu suggests that the top shape was formed by surface landslides when the rotation
period was 3.5 to 3.75 hours [9]. Following a previous study [13], which suggested that the east-west asymmetry of the craterrims on Ryugu was caused by the Coriolis forces acting on crater ejecta during a high-speed rotation era, the analysis with
precise topographic correction revealed that three large craters on Ryugu have significant higher rims both on the west andequatorial sides [14]. These craters are more susceptible to the Coriolis force than other craters at the stage of high-speed
rotation, and the average tilt angle of each surrounding terrain is larger than that of other craters. These results as well as
numerical simulations of top-shape formation [15] suggest that the top shape of Ryugu was formed during high-speed rotation
era about 10 million years ago, and that the crater formation and space weathering were proceeded during the spin-downphase.
Several bluer (negative spectral slope in visible wavelengths) craters are sccattered in red (flat spectral slope) areas on
Ryugu. Stratigraphic relationship between craters reveals that bluer craters are younger in this region, suggesting primordialmaterial of Ryugu is bluer and distributed underground [16]. Suface reddening of the bluer material occurred by space
weathering due to solar wind [17]. On the other hand, on (101955) Bennu, the OSIRIS-REx target, redder, flat spectral slope
craters are scattered in blue areas, and the craters changed from red to blue due to space weathering, so younger craters are
redder on Bennu [18]. This means that space weathering progressed in the opposite direction on the two bodies from thesimilar flat-spectral material.
The thermal infrared imager (TIR) onboard Hayabusa2 revealed flat diurnal brightness temperature profiles caused bysurface roughness and derived global thermal inertia of 225 ± 45 J m−2 s−1/2 K−1 [19, 20], indicating higher porosity of boulders
on Ryugu than that of carbonaceous chondrites. In situ measurement by the Mobile Asteroid Surface Scout (MASCOT) also
found low thermal inertia of 295 ± 18 J m−2 s−1/2 K−1 [21]. In contrast, return sample measurement showed that the thermal
inertia of a Ryugu particle with the thickness of < 1 mm is 890 J m−2 s−1/2 K−1 [3], which is higher than the values on theasteroid surface. The thermal skin depth for the diurnal temperature change of Ryugu is about 10 mm, so that mm-scale cracks
may be responsible for the thermal shielding effect on the surface layer of Ryugu. Some dark boulders on Ryugu have thermal
inertia lower than 100 J m−2 s−1/2 K−1, which correspond to porosity >70% [22]. These boulders are considered to be the least
processed materials on Ryugu and may preserve the structure of grain aggregates on the parent porous planetesimal.
References[1] Yokoyama T. et al. 2022, Science abn7850. [2] Nakamura E. et al. 2022, Proc. Jpn. Acad. Ser. B 98:227. [3] Nakamura T.
et al. 2022, Science abn8672. [4] Ito M. et al. 2022, Nat. Astron. doi:10.1038/s41550-022-01745-5. [5] Yabuta H. et al. 2022,
Abstract #2241, 53rd LPSC. [6] Pilorget C. et al. 2021, Nat. Astron. doi:10.1038/s41550-021-01549-z. [7] Kitazato K. et al.
2019, Science 364, 273. [8] Sugita S. et al. 2019, Science 364, aaw0422. [9] Watanabe S. et al. 2019, Science 364, 268. [10]Arakawa, M. et al. 2020, Science 368, 67. [11] Sugiura, K. et al. 2021, Icarus 365, 114505. [12] Kanamaru M. et al. 2021,
JGRE 126. [13] Hirata N. et al. 2021, Icarus 354, 114073. [14] Yamada R. 2022, Master Thesis, Nagoya Univ. [15] Sugiura K.
et al. 2021, Icarus 365, 114505. [16] Morota T. 2022 Science 368, 654. [17] Tatsumi et al. 2021, Nat. Comm. 12, 5837. [18]DellaGiustina, D. N. et al. 2020 Science 370, eabc3660. [19] Okada, T. et al. 2020, Nature 579, 518. [20] Shimaki, Y., et al.
2021, Icarus 348, 113835. [21] Hamm et al. 2020, Mon. Not. R. Astron. Soc. 496, 2776. [22] Sakatani, N. et al. 2021, Nat.
Astron. 5, 766.