1
Supplementary Information
Primordial aqueous alteration recorded in water
-
soluble organic molecules from
the carbonaceous asteroid (162173) Ryugu
Y
oshinori Takano
1,2
*
, Hiroshi Naraoka
3
, Jason P. Dworkin
4
, Toshiki Koga
1
, Kazunori Sasaki
2,5
, Hajime
Sato
5
, Yasuhiro Oba
6
, Nanako O. Ogawa
1
, Toshihiro Yoshimura
1
, Kenji Hamase
7
, Naohiko Ohkouchi
1
,
Eric T. Parker
4
, Jos
é
C. Aponte
4
, Daniel P. Glavin
4
, Yoshihiro Furukawa
8
, Junken Aoki
9
, Kuniyuki
Kano
9
, Shin
-
ichiro M. Nomura
10
, Francois
-
Regis
Orthous
-
Daunay
11
, Philippe Schmitt
-
Kopplin
12,13,14
,
Hayabusa2
-
initial
-
analysis SOM team
#
, Hisayoshi Yurimoto
15
, Tomoki Nakamura
8
, Takaaki Noguchi
16
,
Ryuji Okazaki
3
, Hikaru Yabuta
17
, Kanako Sakamoto
18
, Toru Yada
18
, Masahiro Nishimura
18
, Aiko
Nakato
18
, Akiko Miyazaki
18
, Kasumi Yogata
18
, Masanao Abe
18
, Tatsuaki Okada
18
, Tomohiro Usui
18
,
Makoto Yoshikawa
18
, Takanao Saiki
18
, Satoshi Tanaka
18
, Fuyuto Terui
19
, Satoru Nakazawa
18
, Sei
-
ichiro
Watanabe
20
, Yuichi Tsuda
18
, and Shogo Tachibana
18, 21
1
Biogeochemistry Research Center (BGC), Japan Agency for Marine
-
Earth Science and Technology
(JAMSTEC), Natsushima, Yokosuka 237
-
0061, Japan.
2
Institute for Advanced Biosciences (IAB), Keio University, Kakuganji, Tsuruoka, Yamagata 997
-
0052, Japan.
3
Department of Earth and Planetary Sciences, Kyushu University,
744 Motooka, Nishi
-
ku, Fukuoka 819
-
0395,
Japan.
4
Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
5
Human Metabolome Technologies Inc., Kakuganji, Tsuruoka, Yamagata 997
-
0052, Japan.
6
Institute of Low Temperature Science (ILTS),
Hokkaido
University
, N19W8 Kita
-
ku, Sapporo 060
-
0819,
Japan.
7
Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812
-
0054, Japan.
8
Department of Earth Material Science,
Tohoku University, Sendai 980
-
8578, Japan
.
9
Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo,
Hongo, Tokyo 113
-
0033,
Japan.
10
Department of Robotics Graduate school of Engineering, Tohoku University, Sendai, 980
-
8579,
Japan.
11
Université Grenoble Alpes, Centre National
de la Recherche Scientifique (CNRS), Centre National
d'Etudes Spatiales, L'Institut de Planétologie et d'Astrophysique de Grenoble, 38000 Grenoble, France.
12
Technische Universität München, Analytische Lebensmittel Chemie, 85354 Freising, Germany.
13
Max Planck Institute for Extraterrestrial Physics, 85748 Garching bei München, Germany.
14
Center for Research and Exploration in Space Science and Technology, NASA Goddard Space Flight
2
Center, Greenbelt, MD 20771, USA.
15
Department of Earth and Planetary Sciences, Hokkaido University,
Sapporo 060
-
0810, Japan
.
16
Department of Earth and Planetary Sciences,
Kyoto University, Kyoto 606
-
8502, Japan
.
17
Department of Earth and Planetary Sciences, Hiroshima University, Higashi
-
Hiroshima 739
-
8526, Japan.
18
Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA),
Sagamihara 252
-
5210, Japan
.
19
Kanagawa Institute of Technology, Atsugi 243
-
0292, Japan.
20
Department of Earth and Environment Sciences, Nagoya University, Nagoya 464
-
8601, Japan.
21
UTokyo Organization for Planetary and Space Science (UTOPS), University of Tokyo, 7
-
3
-
1 Hongo, Tokyo
113
-
0033, Japan.
*
Corresponding author:
E
-
mail:
takano
(a)
jamstec.go.jp
#The Hayabusa2
-
initial
-
analysis SOM
(Soluble Organic Matter)
team:
Hiroshi Naraoka, Yoshinori Takano, Jason P. Dworkin, Kenji Hamase, Aogu Furusho
, Minako Hashiguchi,
Kazuhiko Fukushima, Dan Aoki, José C. Aponte, Eric T. Parker, Daniel P. Glavin, Hannah L. McLain, Jamie
E. Elsila, Heather V. Graham, John M. Eiler, Philippe Schmitt
-
Kopplin, Norbert Hertkorn, Alexander Ruf,
Francois
-
Regis Orthous
-
Daun
ay, Cédric Wolters, Junko Isa, Véronique Vuitton, Roland Thissen, Nanako O.
Ogawa, Saburo Sakai, Toshihiro Yoshimura, Toshiki Koga, Haruna Sugahara, Naohiko Ohkouchi, Hajime Mita,
Yoshihiro Furukawa, Yasuhiro Oba, Yoshito Chikaraishi,
Takaaki Yoshikawa, Sa
toru Tanaka, Mayu Morita,
Morihiko Onose, Daisuke Araoka, Fumie Kabashima, Kosuke Fujishima, Hajime Sato, Kazunori Sasaki,
Kuniyuki Kano, Shin
-
ichiro M. Nomura, Junken Aoki, Tomoya Yamazaki, Yuki Kimura.
3
Supplementary
Notes
Sample process used for the initial analysis
of
Ryugu chamber A and C samples
A summarized description of the onsite process by which samples were collected from the asteroid
Ryugu was reported by the Hayabusa2 International Team
[1
-
3]
. This description was followed by
the
initial
analysis
team
[4
-
9]
with regard to 1) chemistry (i.e., comprehensive description), 2) petrology and mineralogy
for coarse grains (i.e., mm
-
sized grains), 3) petrology and mineralogy for fine grains (i.e., <100
μ
m
-
sized
grains), 4) volatile components (i.e., noble gas
and
inorganic and organic gas
es
), 5) ins
oluble organic matter
(IOM) (i.e., macromolecular organic matter),
and
6) soluble organic matter (SOM) (i.e., extractable organic
molecules), in combination with the phase 2 curational description
[10
-
12]
.
A
photograph of the samples
(A0106
and
C0107) before extraction is shown in
Figure S1
. We present a concept b
ased on the dimensions of
chemical resolution and chemical variation (
Figure S2
). Further science proposals after the initial analysis will
be advanced by the international announcement of opportunity (AO) in
the
Astromaterials Science Research
Group (ASRG) of ISAS/JAXA.
Supplementary
Methods
Sequential solvent extraction for Ryugu A0106
and
C0107
The detailed procedure for
extracting
organic molecules from the Ryugu samples has been described in
the literature
[8]
and the scheme (
Figure S3
).
In brief, we extracted organic molecu
les from the A0106 (13.08
mg) and C0107 (10.73 mg) Ryugu samples with hot water (TAMAPURE
-
AA, Tama Chemicals Co., Ltd.) at
105 °C for 20 h in N
2
-
purged and flame
-
sealed glass ampoules. After the extraction, the contents were
transferred from the ampoule to a glass vial. The glass vial was centrifuged for 8
min at 14,000
rpm,
after
which
the supernatant was transferred to another sample
extraction
vial. The glass ampoule was rinsed with
200
μ
L
of
H
2
O,
and
then the H
2
O solution was transferred to the residue
-
containing vial, which was further
mixed by shaking. The glass vial was centrifuged for 8
min at 14,000
rpm,
after which
the supernatant was
transferred to the sample
extraction
vial. This step was repeated,
and
then the combined 600
μ
L
of
solution
was mixed well by shaking (i.e., the
water/rock
ratio was normalized
to
600
μL
of H
2
O:10 mg of initial bulk).
The hot water extract was split into 250
μ
L (KU) and 250
μ
L (GSFC) for amino acid analysis and 100
μ
L
(JAMSTEC) for the analysis
in the
present report an
d
that of
[13]
.
Separate aggregates of A0106 (17.15 mg) and C0107 (17.36 mg) were extracted by a series of organic
solvents with
the assistance
of ultrasonication (15 min) in the following order: hexane (hexane 5000,
FUJIFILM Wako, 200
μ
L
×
3), dichloromethane (DCM, dichloromethane 5000, FUJIFILM Wako, 200
μ
L
×
3), methanol (MeOH, QTOFMS grade, FUJIFILM Wako, 200
μ
L
×
3) and H
2
O (200
μ
L
×
3, TAMAPURE
-
AA, Tama Chemicals Co., Ltd.). After sonication and centrifugation (12,000 rpm, 5 min), the liquid extract
was decanted. For further details, please refer to th
e reference
[8]
.
We concurrently performed the same
4
procedure with
the
Murchison meteorite and
the
Murray meteorite
[
8,14,
15]
to assess CM group references
with the same normalization of
the water/rock
ratio (i.e.,
600
μL
of H
2
O: 10 mg of initial bulk each
).
The hot
water extract was also analyzed
using
the same procedure as
in
the present report. P
rior to analysis, all
glassware used
was
heated in an oven at 500 °C for 3
h to remove possible organic contaminants.
Supplementary Discussion
Diverse and unique
colors
of the sequential solvent extracts
The
colors
of the sequential solvent extracts are diverse and chemically interesting
,
as shown in
Figure
S5.
We observed that the
hot water extracts (#7
-
1) from
Ryugu
A0106 and C0107 were colorless and
transparent after extraction.
Then, we observed diverse colored supernatants during sequential extractions from
the aggregate samples. The colors of the extracts indicate the chemical features of the extractable organic
molecules, which inherent the affinity of the solvent from low to
high polarity (i.e., they depend o
n
hydrophilicity, hydrophobicity, and amphiphilicity
[8,16]
. Potentially, dissolved inorganic species and
organic‒inorganic complex molecules exhibit chromaticity depending on the solvent affinity
[13,16]
.
Figure
S6
represents the soluble nitrogen from
the
initial bulk to the sequential extraction, i.e
.
, the fraction of SOM
(
f
SOM
) normalized by the nitrogen
-
based relative abundance (%) for Ryugu A0106, C0107 and
the
CI reference
of Orugeil.
Notably,
the extractable inorganic carbon and inorganic nitrogen balance are operationally included
in the inorganic fraction (
f
Inorganics
)
and
soluble organic fraction (
f
SOM
).
Here, the theoretical mass balance
equation of the carbon and nitrogen isotopic compositions is expressed as follows:
f
IB
×
δ
13
C
IB
=
f
Inorganics
×
δ
13
C
Inorganics
+
f
SOM
×
δ
13
C
SOM
+
f
IOM
×
δ
13
C
IOM
[
i
]
f
IB
×
δ
15
N
IB
=
f
Inorganics
×
δ
15
N
Inorganics
+
f
SOM
×
δ
15
N
SOM
+
f
IOM
×
δ
15
N
IOM
[
ii
]
where
f
is the number of moles of carbon and nitrogen as
,
f
IB
=
f
Inorganics
+
f
SOM
+
f
IOM
[
iii
]
Since this
formula
is a theoretical equation, we note that inorganic carbon and nitrogen are
practically
combined with
f
SOM
during wet chemical processes
[13]
, and volatile carbon and nitrogen are not included in
f
IOM
.
To date, organic analysis of the pristine initial bulk (#1), hexane (#2), dichloromethane (DCM) (#3),
methanol (MeOH) (#4), and water (#5) fractions for the sequence from low polarity to high polarity and hot
water (#7
-
1, this study; #7
-
2 HCl), DCM/MeOH (#
8), formic acid (FA) (#9, this study), hydrochloric acid
(HCl) (#10, this study), and IOM (#11) fractions has been classified
within
the scope of soluble organic
molecules
[
13,
17
-
21]
. We obtained ultraviolet (UV)
/visible
absorption spectra of the extracts to acquire further
organic chemical information and search for novel organic molecules
[22,23]
.
UV‒vis spectroscopy
of the
organic extracts
5
The UV‒vis spectra of all #5 extracts (H
2
O extracts) show no clear peak, although the
spectra of the
extracts of Ryugu A0106 and C0107 have a trace peak at
~
204
nm (
Figure S7 A
–
D
). The spectra of the Ryugu
#7
-
1 extracts (hot H
2
O extracts) showed a peak at
~
214 nm. A slight peak at
~
214 nm was present in the
spectrum of the Orgueil
extract
but
was
absent in
that of
the serpentine blank
extract
(
Figure S7 E
–
H
). The
origin of this signal is unclear, but many organic compounds, including N
-
containing organic compounds
,
have
a peak
in
this range
[24]
.
The spectra of the Ryugu #7
-
2 extracts (HCl extracts)
were
similar to
those
of
serpentine (
Figure S7 I
–
L
). The spectrum of
the
Orgueil extract clearly differ
s
from that of serpentine and
Ryugu, showing two peaks at
~
225 and
~
338 nm. The two characteristic peaks in the HCl extract do not appear
in
the reference
HCl solution but can be
attributed to
FeCl
3
in HCl. Thus, the spectrum indicates that this
extract contains Fe
3+
. The
absorption
of short
-
wavelength visible light would also be consistent with the visible
yellowish
color
of this extract. All #9 extracts (formic acid extracts) showed a peak at
~
207 nm, which
corresponded
to a signal from formic acid (
Figure S7 M
–
P
). However, N
-
containing organic compounds also
have a peak
in
this range
[24]
, and N
-
heterocyclic compounds were found in the #9 extracts of Ryugu samples
and
the
Orgueil meteorite by SALDI
-
MS (
Figure S8
). Thus, the compounds may provide a minor contribution
to this signal. The extra
cts of Ryugu samples and the Orgueil meteorite additionally showed a peak at
~
282
nm. This signal is
attributed to
Fe
3+
,
as shown by the spectrum of
the
HCl solution containing FeCl
3
(
Figure
S7
).
High
-
resolution mass spectrometry
of
the pinkish formic acid extracts
We traced the molecular characterization of the pinkish formic acid extracts (#9) and
the
nitrogen
isotopic profiles of
the
“extract” during the sequential extraction
until
the final insoluble organic matter (IOM)
was obtained
(
Figure S8
).
The extracted formic acid fraction (#9) was dropped in a pit on a glass
slide
and
dried
on
a clean bench at ambient temperature.
A platinum sputtering
deposit was applied
to
the glass
slide
for
surface
-
assisted laser desorption/ionization (SALDI) mass spectrometry (MS)
[2
5]
[73]
.
Each spectrum
contains many unassigned mass signals, but the elemental formula of C
n
H
2n
-
m
N (n = 10
~
23, m = 6
~
10)
is
exclusively contained in the #9 extracts of Ryugu samples and
the
Orgueil meteorite (
see also
Figure S8
).
These compounds have been found in carbonaceous chondrites and
are
assigned as N
-
heterocyclic compounds
,
including alkylpyridines
[8,17,26]
. The contents were higher in C0107 than
in
A0106 but lower than
those
in
the Orgueil
and Murchison
meteorites
. The relative abundances between differently saturated series (e.g.,
C
n
H
2n
-
6
N and C
n
H
2n
-
8
N) indicate that
the
Ryugu samples and the Orgueil meteorite are comparable, while the
Murchison meteorite is enriched in
a
more saturated formula.
A
difference in the saturation of CHN compounds
was previously found between less saturated CHN compounds in CM and more saturated CHN compounds in
CR chondrites
[14]
. The difference between
the
Ryugu/Orgueil and Murchison
meteorites
implies that
hy
drogenation was less substantial in Ryugu and the parent asteroid of the Orgueil meteorite. Carbon number
6
distributions in each series (e.g., n = 17
~
21 in C
n
H
2n
-
8
N of Ryugu C0107
and
n = 10
~
19 in C
n
H
2n
-
8
N of the
Murchison extract
[8]
)
show
that the Ryugu samples and Orgueil meteorite contain larger CHN compounds
than the Murchison
meteorite
, suggesting that the elongation reaction of the carbon chain was more substantial
in their parent asteroids. This
result
may be consistent with more substantial aqueous reactions in Ryugu and
the parent asteroids of CI chondrites than in the Murchison CM chondrite
[
4
]
. The carbon number distributions
also show that the CHN compounds in A0106 are slightly smaller than
th
ose
in C0107, implying a potential
difference in the chain elongation reaction in the asteroid Ryugu.
Spectroscopic
FTIR references
for the soluble components
To further confirm the
presence of
soluble organic matter,
FTIR spectra of the DCM and methanol
extracts from the Ryugu samples were obtained, as shown in
Figure S9
(A0106
and
C0107). The predominant
absorption at ~1000 cm
-
1
is derived from the Si
-
O stretching band of silicates in both extracts. Differences in
the width and shape of the Si
-
O band between the two samples might be attributable to
differences
in the
composition, size, and/or shape of the silicate grains
[27]
. In addition, the A0106 extract shows several
absorptions at 1300
-
1600 cm
-
1
, which might be at
tributed to the aromatic C=C and/or N
-
heterocyclic C=N
bands
[28]
.
According to
the distribution of alkylated N
-
heterocycles in the A0106 extract
[8]
, the observed
absorptions, as well as the weak absorptions at ~2900 cm
-
1
(C
-
H stretch), might be partially derived from N
-
heterocycles. In contrast, the C=C/C=N and C
-
H stretching bands were
in
significant for the C0107 extract. A
similar signature is also inferred from the distribution of N
-
heterocycles
,
in which the degree of alkylation in
C0107 is less than that in A0106 (
Figure S9
). These features may be explained by the different histories
of
both samples on the parent body. Since the A0106 sample is derived from the surface of the asteroid Ryugu, it
should have been expose
d to energetic particles, such as cosmic rays and solar wind, which may modify
organics and minerals
[29]
. The A0106 sample shows a tiny absorption band
at ~3600 cm
-
1
attributed to OH
stretching in minerals
[30]
, which could be caused b
y residual water on th
e parent body.
7
Supplementary
Figure S1.
Profiles of samples obtained from the asteroid Ryugu (162173) in this study.
(A, B)
Photographs of initial
sample
A0106
(
a
total
of
38.4 mg, with normal light and UV light under a
microscope) obtained from the asteroid Ryugu (162173) at the 1
st
touchdown sampling location
[1,2]
.
(C, D,
E, F)
Ph
otographs of initial C0107
samples (
37.5 mg
in total
, with normal light and UV light under a
microscope) obtained from the asteroid Ryugu (162173) at the 2
nd
touchdown sampling location
[1,2]
.
Here,
we observed carbonate fluorescence (indicated by green arrows)
under
UV light under the microscope of Leica
M205 FA
microscope
.