Science of solar system materials examined from Hayabusa and future missions (II)Ikeshita/MEF/JAXA-ISAS

Editorial Board (March 2017)
Editor-in-Chief
Yasuo Ogawa, Tokyo Institute of Technology, Japan

Vice Editors-in-Chief
Masato Furuya, Hokkaido University, Japan
Solid Earth Science

Nozomu Nishitani, Nagoya University, Japan
Space Science

Editors
Valerio Acocella
Ryosuke Ando
Yosuke Aoki
Kimiyuki Asano
Nanan Balan
Stephen Bannister
Paul Bedrosian
Phil Cummins
Koji Fukuma
Thomas Hobiger
Hauke Hussmann
Art Jolly
Attila Komjathy
Alexey Kuvshinov

Juanjo Ledo
Huixin Liu
Takuto Maeda
Koji Matsumoto
Yohei Miyake
Mitsuhiro Nakagawa
Junichi Nakajima
Haruhisa Nakamichi
Yasuhito Narita
Takuya Nishimura
Azusa Nishizawa
Takaaki Noguchi
Masahito Nose
Makiko Ohtake

Keiji Ohtsuki
Kyoko Okino
Taku Ozawa
Severine Rosat
Takeshi Sakanoi
David Shelly
Benoit Taisne
Hiroshi Takenaka
Sunny TamYoshiyuki Tanaka
Yanbin Wang
Yih-Min Wu
Takuji Yamada
Mare Yamamoto

Hiroo Kanamori
Jun'ichiro Kawaguchi
Takafumi Matsui
Hitoshi Mizutani

Toshitaka Tsuda
Zhongliang Wu
Kiyoshi Yomogida

Advisory Board
Benjamin Fong Chao
Bernard Chouet
Yoshimori Honkura
Toshihiko Iyemori

Journal Scope
Earth, Planets and Space (EPS) is the official journal of the Society of Geomagnetism and Earth, Planetary
and Space Sciences, The Seismological Society of Japan, The Volcanological Society of Japan, The
Geodetic Society of Japan, and The Japanese Society for Planetary Sciences.
EPS is a peer-reviewed, open-access journal published under SpringerOpen. It is an international journal
covering scientific articles in the entire field of earth and planetary sciences, particularly geomagnetism,aeronomy, space science, seismology, volcanology, geodesy, and planetary science. EPS also welcomesarticles in new and interdisciplinary subjects, and technical reports on instrumentation and software.
The journal was launched in 1998 and has since published over 3000 articles. All of them are available forfree on SpringerLink:
http://link.springer.com/journal/40623
More information about the journal, its article collections, and the submission process is available on thejournal homepage:
http://earth-planets-space.springeropen.com
Submit your next research article to Earth, Planets and Space via:
https://www.editorialmanager.com/epsp
Yours sincerely,
Prof. Yasuo Ogawa
Editor-in-Chief, Earth, Planets and Space
editor-in-chief@earth-planets-space.org

Earth, Planets and Space
Okada et al. Earth, Planets and Space (2017) 69:31
DOI 10.1186/s40623-017-0617-3

Open Access

PREFACESpecial issue “Science of solar system
materials examined from Hayabusa and future
missions (II)”Tatsuaki Okada1*, Richard P. Binzel2, Harold C. Connolly Jr.3, Toru Yada1 and Keiji Ohtsuki4

observations, and reports of new instruments and methods. We will begin with a brief introduction to the missions of the Hayabusa and its successor Hayabusa2. In
addition, all six manuscripts published in this special
issue are reviewed below.
Hayabusa (formerly MUSES-C) was an engineering
mission organized by the Japan Aerospace Exploration
Agency (JAXA) to demonstrate the technology to returnsamples from a near-Earth asteroid (Kawaguchi et al.
2003). It was launched in 2003, explored the S-type asteroid 25143 Itokawa in 2005, and returned surface samples
from the asteroid to Earth in 2010. The four main technologies demonstrated in this mission during its roundtrip to the asteroid were the ion engine used as the main
thrusters, the optical navigation for approaching andlanding on the asteroid, the sample collection on theasteroid under microgravity conditions, and the hypervelocity reentry of the sample capsule into the terrestrial
atmosphere. These technical challenges were all successfully performed, and the asteroid samples were returned
to Earth. This mission also has scientific significance forelucidating the origin and evolution of the early solar
system based on exploration of a primitive solar systembody. We found that the small S-type asteroid 25143
Itokawa was chondritic in composition and a low-density
rubble pile in structure (e.g., Fujiwara et al. 2006). Mostof its surface was rough and covered with boulders, but asmall portion of its surface, where the samples were collected, was smooth and covered with pebbles (e.g., Yanoet al. 2006). The returned samples have been curated in
JAXA’s Extraterrestrial Sample Curation Center, organized by the Astromaterials Science Research Group,
Institute of Space and Astronautical Science, JAXA (Yadaet al. 2014). About 700 grains have been cataloged thus

Six years have passed since the first asteroid sample wasreturned from the S-type near-Earth asteroid 25143
Itokawa by the JAXA’s Hayabusa mission in 2010 (Yadaet al. 2014). Considerable progress has been made in the
study of surface regolith materials and the understanding of planetary surface processes such as space weathering (Noguchi et al. 2011), the chronology of Itokawa andits dynamic evolution processes (Nagao et al. 2011; Parket al. 2015), and the thermal alteration undergone in parent bodies (Nakamura T et al. 2011). Discussions of new
findings from the Hayabusa-returned samples and froma large collection of meteorites, micrometeorites, andinterplanetary dust particles have continued, especiallyat the annual international Hayabusa symposia of solar
system materials (Okada et al. 2015). Progress in sample return science has driven the next stage of exploration. Now, two new sample return missions to primitive,
volatile-rich asteroids, JAXA’s Hayabusa2 (Tsuda et al.
2013) and NASA’s OSIRIS-REx (Lauretta et al. 2012), areen route to their target bodies, C-type 162173 Ryugu andB-type 101955 Bennu, respectively.
It is our great pleasure to present our second special
issue of the journal Earth, Planets and Space, “Scienceof solar system materials examined from Hayabusa andfuture missions (II).” This special issue is based on discussions during the Hayabusa 2014 symposium, which featured new results from Hayabusa-returned samples andrelated studies, but was also open to any scientific results
regarding primitive bodies and the early solar system,
the results of laboratory experiments and ground-based*Correspondence: okada@planeta.sci.isas.jaxa.jp
1
Institute of Space and Astronautical Science, Japan Aerospace
Exploration Agency, Sagamihara 252‑5210, Japan
Full list of author information is available at the end of the article© The Author(s) 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License(http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium,provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license,
and indicate if changes were made.

1

Science of solar system materials examined from Hayabusa and future missions (II)Okada et al. Earth, Planets and Space (2017) 69:31

Page 2 of 5

and the role of micrometeoroid impacts on Itokawa’s
surface. Based on the structure, mineralogy, and interface between the adhering particles and host grains, lithic
fragments and particles deposited by impact were identified. These particles have morphologies and compositions consistent with impact-generated deposits, suchas impact-generated silica glass, and one was a Ni-free,
metallic Fe-rich, and S-rich assemblage that was likely
generated by vapor recondensation during a micrometeoroid impact. This study shows that even though the regolith of the asteroid Itokawa is young (Nagao et al. 2011;
Noguchi et al. 2011), it has been altered by micrometeoroid impacts.
Volatile-rich carbonaceous meteorites are increasingly attracting the interest of researchers to determine
the implications of the properties of these meteorites
to future missions such as Hayabusa2 and OSIRIS-REx.
King et al. (2015) performed laboratory experiments toconstrain the thermal alteration processes of volatilerich asteroids. CI and CI-like carbonaceous chondrites
provide a record of aqueous alteration in the early solar
system, but those of the latter type seem to have experienced a late-stage period of thermal metamorphism.
To constrain the nature and extent of the aqueous andthermal alteration, the bulk mineralogy and abundanceof H2O in CI chondrites (Ivuna and Orgueil) and CI-likechondrites (Y-82162 and Y-980115) were investigatedusing thermo-gravimetric analysis as well as near- andmid-infrared spectroscopy. Both CI chondrites analyzed
showed significant loss of mass (~30 wt%) and similar
patterns of mass loss upon heating to 1000 °C due todehydration and dehydroxylation of abundant phyllosilicates and Fe-(oxy)hydroxides, as well as the decomposition of Fe sulfides, carbonates, and organics. Infrared
spectra of both CI chondrites have prominent 3-μm features because of bound OH−/H2O in phyllosilicates andFe-(oxy)hydroxides and only minor 11-μm features fromanhydrous silicates. These results indicate completeaqueous alteration and nearly the same degree of hydration experienced in both CI meteorites. In contrast, bothof the CI-like chondrites show lower mass loss and contain less than a half the H2O of the CI chondrites, and the
3-μm feature is nearly absent from spectra, whereas the
11-μm feature is intense. These CI-like chondrites experienced thermal metamorphism at temperatures >500 °C,
which initially caused dehydration and dehydroxylationof phyllosilicates. Concerning future sample return missions, King et al. (2015) also note that the surfaces ofmany C-type asteroids have likely been heated throughimpact metamorphism and/or solar radiation and that
thermally altered carbonaceous chondrites may therefore
be good analogues for the samples that will be returnedby the Hayabusa2 and OSIRIS-REx missions.

far, with information from optical microscopy, scanningelectron microscopy (SEM), and energy-dispersive X-ray
spectroscopy (EDS). Parts of the catalogued samples areavailable to researchers if their research proposals are
accepted through a peer-review process. The results ofprimitive examinations of the Itokawa samples just after
they were returned, as well as data from continued studies of these samples, have been reported in past special
issues (e.g., Nakamura T et al. 2011; Nakamura E et al.
2012). A portion of these detailed studies was introducedin the previous EPS special issue “Science of solar system
materials examined by Hayabusa and future missions.”
Hayabusa2, the second asteroid sample return mission by JAXA, was launched in 2014 and is now on its
way to the asteroid 162173 Ryugu. The target asteroid isclassified as C-type, a volatile-rich carbonaceous type.
The technology of Hayabusa2 is based on that of the first
Hayabusa mission, but its science experiments are more
specified to C-type asteroid and reinforced with the
instruments (Tachibana et al. 2014). The remote sensing instruments are designed to focus on investigating
the degree of hydration of minerals by measuring 3-μm
band absorption features and on physical state of thesurface, such as the thermo-physical properties of theasteroid based on thermal infrared imaging (Okada and
Iwata 2014). The spacecraft has a scientific lander called
MASCOT (Micro-Asteroid Surface Scout) to conduct
observations in situ on the surface of the asteroid (Hoet al. 2016). In the Hayabusa2 mission, scientific measurements will be conducted at a global scale with remotesensing, a local scale with the surface lander, and a microscale through analysis of returned samples. In addition,
an impact experiment will be conducted using a small
carry-on impactor; the excavated fresh, unweatheredmaterials will be observed via remote sensing, and thosematerials will be returned to Earth.
A great deal of new results from the Hayabusareturned samples has been presented at the annual
Hayabusa symposia. In this special issue, another new
finding from microscopic analysis has been provided
by Dobrică and Ogliore (2016). This highlighted paper
reports new microstructures on micron-scale particles.
These researchers investigated the surface textures andchemical compositions of two small particles (RB-DQ040062 and RB-DQ04-0091) returned from the surface of
the asteroid Itokawa by Hayabusa. Using high-resolution
images from scanning electron, helium ion, and scanningtransmission electron microscopy, they identified splash
melts, surface blistering, and numerous small adhering
particles on the Itokawa samples. They extracted sevenfocused ion beam sections from both of these Itokawa
particles, targeting one splash melt and ten adhering particles, to investigate their composition and provenance2

Earth, Planets and Space
Okada et al. Earth, Planets and Space (2017) 69:31

Page 3 of 5(meteorite Millbillillie and a synthetic enstatite) and slabs
of serpentinite and basalt in a vacuum and under purged
air, at a surface temperature of 100 °C, for emergenceangles from 0° to 60°. Complementary reflectance measurements of the four samples were collected. For all samples measured, they found that emissivity and reflectanceboth show the same trend: Significant variations fromvalues obtained at the nadir (0° emergence angle) appear
only for emergence angles ≥ 40°.
Maturilli et al. (2016b) also constructed a new big
database of emissivity and reflectance spectra that characterize asteroid analogues measured under vacuum
conditions. A number of missions, such as NEAR-Shoemaker, Hayabsua, Rosetta, Hayabusa2, and OSIRIS-Rex,
have targeted small bodies in the solar system. Despite
the rich collection of reflectance and emissivity spectral libraries available for asteroid analogues, these data
are mainly based on measurements in air for a spectral
range covering the visible to the mid-infrared spectrum
from 0.4 to 25 µm. To characterize minerals, rocks andmeteorites suitable to serve as surface analogues forasteroids and cometary nuclei in general, spectroscopic
measurements are needed for a wider spectral range andunder vacuum conditions. To fill this gap, these authorsacquired spectral measurements over a large spectral
range (1–100 µm) for several meteorites and other analogues at the PEL of DLR in Berlin. These data provide
more direct and suitable analogues for emissivity andreflectance measurements of asteroid and cometary
surfaces.
At the annual Hayabusa symposia, instrumentationand methodology are essential topics for answering unresolved questions. Remote X-ray spectroscopy is one of
the main instrumental techniques used in missions toterrestrial bodies. Hong and Romaine (2016) have developed sophisticated new X-ray optics that will be appliedin remote planetary X-ray imaging spectrometry. The
compositions of diverse planetary bodies are of fundamental interest to planetary science; they provide clues
about the formation and evolutionary history of target
bodies and the solar system. The masses and volumesof instruments used in focusing X-ray optics have been
too large for resource-limited in situ missions; therefore,near-target X-ray observations of planetary bodies havebeen limited to those of simple collimator-type X-ray
instruments. However, Hong and Romaine (2016) have
now introduced the new Miniature lightweight WolterI focusing X-ray Optics (MiXO), which uses metalceramic hybrid X-ray mirrors based on electroformed
nickel replication and plasma thermal spray processes.
MiXO enables compact, powerful imaging by X-ray telescopes suitable for future planetary missions, especiallyfor observing relatively small planetary bodies such as

Chan et al. (2016) developed a novel method using gas
chromatography, combustion, and isotope ratio mass
spectrometry to determine compound-specific nitrogen isotope compositions with an achiral column, which
was previously shown to offer high precision for nitrogenisotopic analysis. They applied this method to determine
the amino acid contents and stable nitrogen isotopic
compositions of individual amino acids from thermally
metamorphosed (above 500 °C) Antarctic carbonaceouschondrites, specifically the Ivuna-like (CI-like) meteorite Y-980115 and the Ornans-like (CO3.5) meteorite
ALHA77003. In ALHA77003, almost no amino acids
were detected because of its extensive history of thermal alteration. In Y-980115, amino acids were identified,
and the δ15N values of selected amino acids are clearly
extraterrestrial. Y-980115 has experienced an extended
period of aqueous alteration, as indicated by the presenceof hydrous mineral phases. This meteorite has also been
exposed to at least one short-lived period of thermal metamorphism post-hydration. Chan et al. (2016) also suggest that these carbonaceous chondrite samples are goodanalogues for the target asteroid of the Hayabusa2 mission, Ryugu, which is a C-type asteroid likely composedof heterogeneous materials including both hydrated anddehydrated minerals.
In Hayabusa, Hayabusa2, OSIRIS-REx, and other missions, infrared spectroscopy helps us investigate surface
mineralogy, the degree of hydration of silicates, and theexistence of organics. Many databases have been constructed based on laboratory experiments to calibrate
and interpret the observational results. However, inmany cases, these experiments have been conductedunder conditions too simplified to apply findings to real
observations. Maturilli et al. (2016a) have developed andorganized the Planetary Emissivity Laboratory (PEL) of
the German Aerospace Center (DLR) and have demonstrated in laboratory experiments the dependence of laboratory-measured emissivity spectra on the emergenceangle. Most of the previous work has been based onreflectance measurements in the visible to near-infrared
spectral region, on emissivity measurements of flat, solid
surfaces, and on measurements from the nadir direction,
which are not directly applicable to the analysis of remotesensing data. Small bodies such as the asteroid Itokawa(the target of the Hayabusa mission) have very irregularsurfaces, which is likely also the case for the asteroids
Ryugu and Bennu, the targets of the Hayabusa2 and the
OSIRIS-REx missions, respectively. The spectra fromsuch rough surfaces are difficult to compare with previously reported laboratory spectra. Maturilli et al. (2016a)
set up a series of spectral measurements to investigate
this problem in the 1- to 16-µm spectral range and measured the emissivity of two asteroid analogue materials

3

Science of solar system materials examined from Hayabusa and future missions (II)Okada et al. Earth, Planets and Space (2017) 69:31

Page 4 of 5

asteroids and comet nuclei. These researchers have alsopresented several example configurations of MiXO telescopes and have demonstrated their performance relative to an alternative approach, micropore optics, which
is being employed for the first planetary focusing X-ray
telescope, the Mercury Imaging X-ray Spectrometer-T
onboard BepiColombo. X-ray imaging spectroscopy using
MiXO will open a wide area for new discoveries in planetary science and will greatly enhance our understandingof the natures and origins of diverse planetary bodies.
All manuscripts in this special issue are fruitful andconstructive for the ongoing discussion of the origin andevolution of the early solar system, and for the prospectsof future volatile-rich carbonaceous-type asteroid missions such as Hayabusa2 and OSIRIS-REx, which willsoon reach their destinations and commence observations, and then return abundant samples to Earth. Furthermore, these activities provide motivation for new
missions to yet unvisited types of primitive bodies, which
has led to NASA’s selection of the Psyche mission for rendezvous with a metallic core (Elkins-Tanton et al. 2016)
and the Lucy mission for multiple flybys of Trojan asteroids (Levison et al. 2016), and will hopefully lead to landing on a Trojan asteroid in a future mission (Okada et al.
2017).

R, Sasaki S, Uesugi K (2006) The rubble‑pile asteroid Itokawa as observed
by Hayabusa. Science 312:1330–1334
Ho TM, Baturkin V, Grimm C, Grundmann JT, Hobbie C, Ksenik E, Lange C,
Sasaki K, Schlotterer M, Talapina M, Termtanasombat N, Wejmo E, Witte L,
Wrasmann M, Wuebbels G, Roessler J, Ziach C, Findlay R, Biele J, Krause C,
Ulamec S, Lange M, Mierheim O, Lichtenheldt R, Maier M, Reill J, Sedlmayr
HJ, Bousquet P, Bellion A, Bompis O, Cenac‑Morthe C, Deleuze M, Fredon
S, Jurado E, Canalias E, Jaumann R, Bibring JP, Glassmeier KH, Hercik D,
Grott M, Celotti L, Cordero F, Hendrikse J, Okada T (2016) MASCOT: themobile asteroid surface scout onboard the Hayabusa2 mission. Space Sci
Rev. doi:10.1007/s11214‑016‑0251‑6
Hong J, Romaine S (2016) Miniature lightweight X‑ray optics (MiXO) for surface
elemental composition mapping of asteroids and comets. Earth Planets
Space 68:35. doi:10.1186/s40623‑016‑0409‑1
Kawaguchi J, Uesugi K, Fujiwara A (2003) The MUSES‑C mission for the sample
and return—its technology development status and readiness. Acta
Astronaut 52:117–123
King AJ, Solomon JR, Schofield PF, Russell SS (2015) Characterising the CI
and CI‑like carbonaceous chondrites using thermogravimetric analysis
and infrared spectroscopy. Earth Planets Space 67:198. doi:10.1186/
s40623‑015‑0370‑4
Lauretta DS, The OSIRIS‑REx Team (2012) An overview of the OSIRIS‑REx aster‑oid sample return mission. Lunar Planet Sci Conf 43:#2491
Levison HF, Team Lucy Science (2016) Lucy: surveying the diversity of the
Trojan asteroids, the fossils of planet formation. Lunar Planet Sci Conf
47:2061
Maturilli A, Helbert J, Ferrari S, D’Amore M (2016a) On the effect of emergenceangle on emissivity spectra: application to small bodies. Earth Planets
Space 68:84. doi:10.1186/s40623‑016‑0464‑7
Maturilli A, Helbert J, Ferrari S, Davidsson B, D’Amore M (2016b) Characteriza‑tion of asteroid analogues by means of emission and reflectance spec‑
troscopy in the 1‑ to 100‑µm spectral range. Earth Planets Space 68:113.
doi:10.1186/s40623‑016‑0489‑yNagao K, Okazaki R, Nakamura T, Miura YN, Osawa T, Bajo K, Matsuda S, Ebihara
M, Ireland TR, Kitajima F, Naraoka H, Noguchi T, Tsuchiyama A, Yurimoto
H, Zolensky ME, Uesugi M, Shirai K, Abe M, Yada T, Ishibashi Y, Fujimura A,
Mukai T, Ueno M, Okada T, Yoshikawa M, Kawaguchi J (2011) Irradiation
history of Itokawa regolith material deduced from noble gases in the
Hayabusa samples. Science 333:1128–1131
Nakamura T, Noguchi T, Tanaka M, Zolensky ME, Kimura M, Tsuchiyama A,
Nakato A, Ogami T, Ishida H, Uesugi M, Yada T, Shirai S, Fujimura A, Oka‑zaki R, Sandford SA, Ishibashi Y, Abe M, Okada T, Ueno M, Mukai T, Yoshi‑
kawa M, Kawaguchi J (2011) Itokawa dust particles: a direct link between
S‑type asteroids and ordinary chondrites. Science 333:1113–1116
Nakamura E, Makishima A, Moriguti T, Kobayashi K, Tanaka R, Kunihiro T, Tuji‑mori T, Sakaguchi C, Kitagawa H, Ota T, Yachi Y, Yada T, Abe M, Fujimura A,
Ueno M, Mukai T, Yoshikawa M, Kawaguchi J (2012) Space environmentof and asteroid preserved on micrograins returned by the Hayabusa
spacecraft. Proc Natl Acad Sci. doi:10.1073/pnas.1116236109
Noguchi T, Nakamura T, Kimura M, Zolensky ME, Tanaka M, Hashimoto
T, Konno M, Nakato A, Ogami T, Fujimura A, Abe M, Yada T, Mukai T,
Ueno M, Okada T, Shirai K, Ishibashi Y, Okazaki R (2011) Incipient space
weathering observed on the surface of Itokawa dust particles. Science
333:1121–1125
Okada T, Iwata T (2014) Near infrared spectroscopy and thermal infrared
imagery on Hayabusa2: hydrated and physical state of C‑class asteroid
1999JU3. In: Ip WH (ed) New results in observations and space explora‑tion of asteroids, Proc. Intl. CJMT‑1 workshop on asteroidal science,
Macao, Oct 16–17, 2012, pp 97–112
Okada T, Zolensky ME, Ireland TR, Yada T (2015) The earth, planets andspace special issue: “science of solar system materials examined from
Hayabusa and future missions”. Earth Planets Space 67:116. doi:10.1186/
s40623‑015‑0235‑x
Okada T, Iwata T, Matsumoto J, Bibring JP, Ulamec S, Jaumann R, Nakamura R,
Yano H, Kebukawa Y, Aoki J, Kawai Y, Terada K, Toyoda M, Ito M, Yabuta
K, Yurimoto H, Saito Y, Yokota S, Okamoto C, Matsuura S, Tsumura K,
Yonetoku D, Mihara T, Matsuoka A, Nomura R, Hirai T, Grand N, Cottin H,
Thirkell L, Briois C, Saiki T, Kato H, Mori O, Kawaguchi J (2017) Science andexploration of a Jupiter Trojan asteroid in the Solar Power Sail mission.
Lunar Planet Sci Conf 48:#1828

Authors’ contributions
TO is the lead guest editor of this special issue. RPB, HCC, TY, KO serve as theguest editors of this special issue. All authors read and approved the final
manuscript.
Author details
1
Institute of Space and Astronautical Science, Japan Aerospace Exploration
Agency, Sagamihara 252‑5210, Japan. 2 Earth, Atmospheric and Planetary
Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139‑4307,
USA. 3 Department of Earth and Environmental Sciences, Kingsborough Com‑munity College of the City University of New York, Brooklyn, NY 11235‑2398,
USA. 4 Department of Earth and Planetary Sciences, Kobe University,
Kobe 657‑8501, Japan.
Received: 5 February 2017 Accepted: 5 February 2017

References
Chan QHS, Chikaraishi Y, Takano Y, Ogawa NO, Ohkouchi N (2016) Amino acidcompositions in heated carbonaceous chondrites and their compound‑
specific nitrogen isotopic ratios. Earth Planets Space 68:7. doi:10.1186/
s40623‑016‑0382‑8
Dobrică E, Ogliore RC (2016) Adhering grains and surface features on
two Itokawa particles. Earth Planets Space 68:21. doi:10.1186/
s40623‑016‑0391‑7
Elkins‑Tanton LT, Asphaug E, Bell J, Bercovici D, Billis BG, Binzel RP, Bottke
WF, Goldsten J, Jaumann R, Jun I, Lawrence DJ, Marchi S, Oh D, Park R,
Peplowski PN, Polanskey CA, Prettyman TH, Raymond CA, Russel CT, Weiss
BP, Wenkert DD, Wieczorek M, Zuber MT (2016) Asteroid (16) psyche: thescience of visiting a metal world. Lunar Planet Sci Conf 47:#1631
Fujiwara A, Kawaguchi J, Yeomans DK, Abe M, Mukai T, Okada T, Saito J, Yano H,
Yoshikawa M, Scheeres DJ, Barnouin‑Jha O, Cheng AF, Demura H, Gaskell
RW, Hirata N, Ikeda H, Kominato T, Miyamoto H, Nakamura AM, Nakamura

4Earth, Planets and Space
Okada et al. Earth, Planets and Space (2017) 69:31

Page 5 of 5

Park J, Turrin BD, Herzog GF, Lindsay FN, Delaney JS, Swisher CC, Uesugi M,
Karouji Y, Yada T, Abe M, Okada T, Ishibashi Y (2015) 40Ar/39Ar age ofmaterial returned from asteroid 25143 Itokawa. Meteorit Planet Sci.
doi:10.1111/maps.12564
Tachibana S, Abe M, Arakawa M, Fujimoto M, Iijima Y, Ishiguro M, Kitazato K,
Kobayashi N, Namiki N, Okada T, Okazaki R, Sawada H, Sugita S, Takano Y,
Tanaka S, Watanabe S (2014) Hayabusa2: scientific importance of samples
returned from C‑type near‑earth asteroid (162173) 1999JU3. Geochem J
48:571–587. doi:10.2343/geochemj.2.0350
Tsuda Y, Yoshikawa M, Abe M, Minamino H, Nakazawa S (2013) System designof the Hayabusa2—asteroid sample return mission to 1999 JU3. Acta
Astronaut 91:356–362. doi:10.1016/j.actaastro.2013.06.028

Yada T, Fujimura A, Abe M, Nakamura T, Noguchi T, Okazaki R, Nagao K,
Ishibashi Y, Shirai K, Zolensky ME, Sandford S, Okada T, Uesugi M, Karouji Y,
Ogawa M, Yakame S, Ueno M, Mukai T, Yoshikawa M, Kawaguchi J (2014)
Hayabusa returned sample curation in the planetary material sample
curation facility of JAXA. Meteorit Planet Sci 49:135–153
Yano H, Kubota T, Miyamoto H, Okada T, Scheeres D, Takagi Y, Yoshida K, Abe
M, Abe S, Barnouin‑Jha O, Fujiwara A, Hasegawa S, Hashimoto T, Ishiguro
M, Kato M, Kawaguchi J, Mukai T, Saito J, Sasaki S, Yoshikawa M (2006)
Touchdown of the Hayabusa spacecraft at the Muses Sea on Itokawa.
Science 312:1350–1353

5

Science of solar system materials examined from Hayabusa and future missions (II)FULL PAPER

Open Access

Adhering grains and surface features on two Itokawa
particles
E. Dobrică* and R. C. Ogliore
Earth, Planets and Space 2016, 68:21 DOI: 10.1186/s40623-016-0391-7
Received: 1 May 2015, Accepted: 15 January 2016, Published: 13 February 2016

Abstract
We investigated the surface texture and chemical compositions of two ~40-μm particles returned from the surface regolith ofasteroid Itokawa (RB-DQ04-0062 and RB-DQ04-0091) by the Japan Aerospace Exploration Agency’s Hayabusa mission. We
identified splash melts, surface blistering, and many small adhering particles. Seven focused ion beam sections were extracted
from both Itokawa particles, targeting one splash melt and ten adhering particles to investigate their composition andprovenance and the role of micrometeoroid impacts on Itokawa’s surface. Based on the particle’s structure, mineralogy, andinterface between the adhering particle and host grain, we identified lithic fragments and particles deposited by impact.
These have morphologies and compositions consistent with impact-generated deposits: two have morphologies andcompositions that are consistent with impact-generated silica glass, and one was a Ni-free, metallic Fe, and S-rich assemblage
that was likely generated by vapor recondensation
during a micrometeoroid impact. This study showsthat, even though its regolith is young,micrometeoroid impacts have altered the regolith ofasteroid Itokawa.

Keywords: Asteroid, Micrometeoroid, Regolith,
Space weathering

Figure 1*Corresponding author: E. Dobrică, edobrica@unm.edu

FULL PAPER

Open Access

Miniature lightweight X-ray optics (MiXO) for surface
elemental composition mapping of asteroids and comets
Jaesub Hong*, Suzanne Romaine and The MiXO team
Earth, Planets and Space 2016, 68:35 DOI: 10.1186/s40623-016-0409-1
Received: 30 April 2015, Accepted: 7 January 2016, Published: 29 February 2016

Abstract
The compositions of diverse planetary bodies are of fundamental interest to planetary science, providing clues to theformation and evolutionary history of the target bodies and the solar system as a whole. Utilizing the X-ray fluorescenceunique to each atomic element, X-ray imaging spectroscopy is a powerful diagnostic tool of the chemical and mineralogicalcompositions of diverse planetary bodies. Until now the mass and volume of focusing
X-ray optics have been too large for resource-limited in situ missions, so near-target
X-ray observations of planetary bodies have been limited to simple collimator-type
X-ray instruments. We introduce a new Miniature lightweight Wolter-I focusing X-ray
Optics (MiXO) using metal-ceramic hybrid X-ray mirrors based on electroformed nickel
replication and plasma thermal spray processes. MiXO can enable compact, powerfulimaging X-ray telescopes suitable for future planetary missions. We illustrate the needfor focusing X-ray optics in observing relatively small planetary bodies such asasteroids and comet nuclei. We present a few example configurations of MiXO
telescopes and demonstrate their superior performance in comparison to analternative approach, micro-pore optics, which is being employed for the firstplanetary focusing X-ray telescope, the Mercury Imaging X-ray Spectrometer-T
onboard Bepicolumbo. X-ray imaging spectroscopy using MiXO will open a large new
discovery space in planetary science and will greatly enhance our understanding of
the nature and origin of diverse planetary bodies.

Keywords: X-ray fluorescence, Elemental abundance, X-ray imaging*Corresponding author: Jaesub Hong, jhong@cfa.harvard.edu
6

Figure 1

Earth, Planets and SpaceLETTER

Open Access

Characterising the CI and CI-like carbonaceous chondrites using
thermogravimetric analysis and infrared spectroscopy
Ashley J. King*, Jake R. Solomon, Paul F. Schofield and Sara S. Russell
Earth, Planets and Space 2015, 67:198 DOI: 10.1186/s40623-015-0370-4
Received: 30 April 2015, Accepted: 1 December 2015, Published: 9 December 2015

Abstract
The CI and CI-like chondrites provide a record of aqueous alteration in the early solar system. However, the CI-like chondrites differ inhaving also experienced a late stage period of thermal metamorphism. In order to constrain the nature and extent of the aqueous
and thermal alteration, we have investigated the bulk mineralogy and abundance of H2O in the CI and CI-like chondrites using
thermogravimetric analysis and infrared spectroscopy.
The CI chondrites Ivuna and Orgueil show significant mass loss (28.5–31.8 wt.%) upon heating to 1000 °C due to dehydration anddehydroxylation of abundant phyllosilicates and Fe-(oxy)hydroxides and the decomposition of Fe-sulphides, carbonates andorganics. Infrared spectra for Ivuna and Orgueil have a prominent 3-μm feature due to bound −OH/H2O in phyllosilicates and Fe-(oxy)hydroxides and only a minor 11-μm feature from anhydrous silicates. These characteristics are consistent with previous studies
indicating that the CI chondrites underwent near-complete aqueous alteration.
Similarities in the total abundance of H2O and 3 μm/11 μm ratio suggest that there is nodifference in the relative degree of hydration experienced by Ivuna and Orgueil.
In contrast, the CI-like chondrites Y-82162 and Y-980115 show lower mass loss (13.8–18.8
wt.%) and contain >50 % less H2O than the CI chondrites. The 3-μm feature is almost
absent from spectra of Y-82162 and Y-980115 but the 11-μm feature is intense. The CI-likechondrites experienced thermal metamorphism at temperatures >500 °C that initiallycaused dehydration and dehydroxylation of phyllosilicates before partial recrystallizationback into anhydrous silicates. The surfaces of many C-type asteroids were probably
heated through impact metamorphism and/or solar radiation, so thermally alteredcarbonaceous chondrites are likely good analogues for samples that will be returned by
the Hayabusa-2 and OSIRIS-REx missions.

Keywords: Meteorites, Asteroids, Aqueous alteration, Dehydration, Hayabusa-2, OSIRIS-REx

Figure 1*Corresponding author: Ashley J. King, a.king@nhm.ac.uk

LETTER

Open AccessAmino acid compositions in heated carbonaceous chondrites andtheir compound-specific nitrogen isotopic ratios
Queenie Hoi Shan Chan*, Yoshito Chikaraishi, Yoshinori Takano, Nanako O. Ogawa andNaohiko Ohkouchi
Earth, Planets and Space 2016, 68:7 DOI: 10.1186/s40623-016-0382-8
Received: 28 April 2015, Accepted: 7 January 2016, Published: 21 January 2016

Abstract
A novel method has been developed for compound-specific nitrogen isotope compositions with an achiral column which waspreviously shown to offer high precision for nitrogen isotopic analysis. We applied the method to determine the amino acid contents
and stable nitrogen isotopic compositions of individual amino acids from the thermally metamorphosed (above 500 °C) Antarctic
carbonaceous chondrites Ivuna-like (CI)1 (or CI-like) Yamato (Y) 980115 and Ornans-like (CO)3.5 Allan Hills (ALH) A77003 with the useof gas chromatography/combustion/isotope ratio mass spectrometry. ALHA77003 was deprived of amino acids due to its extended
thermal alteration history. Amino acids were unambiguously identified in Y-980115, and the δ15N values of selected amino acids(glycine +144.8 ‰; α-alanine +121.2 ‰) are clearly extraterrestrial. Y-980115 has experienced an extended period of aqueousalteration as indicated by the presence of hydrous mineral phases. It has also been exposed to at least one post-hydration short-lived
thermal metamorphism. Glycine and alanine were possibly produced shortly after the accretion event of the asteroid parent bodyduring the course of an extensive aqueous alteration event and have abstained from the short-term post-aqueous alteration heating
due to the heterogeneity of the parent body composition and porosity. These carbonaceous chondrite samples are good analogs thatoffer important insights into the target asteroid Ryugu of the Hayabusa-2 mission, which is a C-type asteroid likely composed ofheterogeneous materials including hydrated and dehydrated
minerals.

Keywords: Carbonaceous chondrites, Meteorites,

Astrochemistry, Compound-specific isotopic
analysis, Nitrogen isotopes, Amino acids, Organic
materials, Meteoritic composition, Gas
chromatography/combustion/isotope ratio mass
spectrometry

Figure 1*Corresponding author: Queenie Hoi Shan Chan, hschan@nasa.gov
7

Science of solar system materials examined from Hayabusa and future missions (II)LETTER

Open AccessOn the effect of emergence angle on emissivity spectra:
application to small bodies
Alessandro Maturilli*, Jörn Helbert, Sabrina Ferrari and Mario D’Amore
Earth, Planets and Space 2016, 68:84 DOI: 10.1186/s40623-016-0464-7
Received: 30 April 2015, Accepted: 6 May 2016, Published: 23 May 2016

Abstract
Dependence of laboratory-measured emissivity spectra from the emergence angle is a subject that still needs a lot of
investigations to be fully understood. Most of the previous work is based on reflectance measurements in the VIS–NIR spectral
region and on emissivity measurements of flat, solid surfaces (mainly metals), which are not directly applicable to the analysisof remote sensing data. Small bodies in particular (c.f. asteroids Itokawa and 1999JU3, the respective targets of JAXA
Hayabusa and Hayabusa 2 missions) have a very irregular surface; hence, the spectra from those rough surfaces are difficult tocompare with laboratory spectra, where the observing geometry is always close to “nadir.” At the Planetary Emissivity
Laboratory of the German Aerospace Center (DLR), we have set up a series of spectral measurements to investigate thisproblem in the 1- to 16-µm spectral region. We measured the emissivity for two asteroid analogue materials (meteorite
Millbillillie and a synthetic enstatite) in vacuum and under purged air, at surface temperature of 100 °C, for emergence angles
of 0°, 5°, 10°, 20°, 30°, 40°, 50°, and 60°. Emissivity of a serpentinite slab, already used as calibration target for the MARA
instrument on Hayabusa 2 MASCOT lander and for the thermal infrared imager spectrometer on Hayabusa 2 orbiter, wasmeasured under the same conditions. Additionally, a second basalt slab wasmeasured. Both slabs were not measured at 5° inclination. Complementaryreflectance measurements of the four samples were taken. For all thesamples measured, we found that for calibrated emissivity, significant
variations from values obtained at nadir (0° emergence angle) appear only for
emergence angles ≥40°. Reflectance measurements confirmed this finding,showing the same trend of variations.

Keywords: The Hayabusa 2 mission, Asteroid analogue materials, Emissivity
measurements, Emergence angle, Infrared spectroscopy

Figure 1*Corresponding author: Alessandro Maturilli, alessandro.maturilli@dlr.de

LETTER

Open Access

Characterization of asteroid analogues by means ofemission and reflectance spectroscopy in the 1- to 100-µm
spectral range
Alessandro Maturilli*, Jörn Helbert, Sabrina Ferrari, Björn Davidsson and Mario D’Amore
Earth, Planets and Space 2016, 68:113 DOI: 10.1186/s40623-016-0489-y
Received: 23 September 2015, Accepted: 13 June 2016, Published: 11 July 2016

Abstract
The last decades have seen a large number of missions targeting small bodies in the solar system. NASA, ESA and JAXA sent
missions to different solar system small bodies (SSSB), and the Japan mission Hayabusa returned samples from the surface of
the S-type asteroid Itokawa. JAXA launched in 2014 a follow-up mission (Hayabusa2) to collect a sample from carbonaceous(C-type) asteroid 1999 JU3 asteroid and bring it back to Earth. The NASA’s OSIRIS-REx mission will launch in September 2016 to
explore the carbonaceous asteroid Bennu. Despite an already existing rich collection of reflectance and emissivity spectral
libraries for asteroid analogues, those are mostly based on measurements in air for a spectral range covering the visible to themedium infrared (approximately, from 0.4 to 25 µm). To characterize minerals, rocks and meteorites suitable for being surface
analogues for asteroids and SSSB in general, spectroscopic measurements
are needed for a wider spectral range and in vacuum, conditions that moreclosely resemble those found on asteroid surfaces. To fill this gap weacquired spectral measurements over a large spectral range (1–100 µm) for
several meteorites and other analogues at the Planetary Emissivity
Laboratory of the German Aerospace Center in Berlin. Those data provide
more direct analogues for asteroid surfaces and expand our existing
database of emissivity and reflectance measurements.

Keywords: Asteroid analogue materials, Emissivity measurements,
Reflectance measurements, Infrared spectroscopy*Corresponding author: Alessandro Maturilli, alessandro.maturilli@dlr.de
8

Figure 1

Information for Contributors
General1.

Manuscripts should be submitted through the journal’s Editorial Manager system(https://www.editorialmanager.com/epsp/default.aspx).

2.

Only papers not previously published will be accepted, and the emphasis is on theoriginality of concept or observation.

3.

Four varieties of article types are available.
3.1“Full papers” without word limit.

3.2“Express Letters” have a limit of 5000 words including the title page, abstract,
keywords, main text, declarations, references, figure legends and table legends.
The sum of the number of figures and tables should be less than or equal to 5.

3.3“Frontier Letters” can be submitted upon invitation by the Editor-in-Chief. “Frontier
Letters” have a limit of 11,000 words including legends for figures and tables. One
figure or table not exceeding one A4 page is counted as 500 words.

3.4
4.

“Technical reports” describe the technical development of instrument or software.

Authors retain the copyright, and distribution of articles is free under cc-by license.

Technical
1.

Manuscripts should be written in English with double spacing.

2.

Each manuscript should be organized in the following order: title, authors’ names,
affiliations, abstract, key words, main text, acknowledgement, appendix, references, andsupplementary materials.

3.

The corresponding author should be clearly indicated.

4.

The abstract is limited to 300 words and should be informative and include principal
findings and conclusions. Please avoid abbreviations.

5.

The main text can have multiple free headings.

6.

High-resolution figures should be provided in the following format; PDF (preferred
format for diagrams), PNG (preferred format for photos or images), EPS ,TIFF, JPEG, BMP.

7.

References must follow the Springer Basic style.

Correspondence
If you have any questions, please contact editorial@earth-planets-space.com.

© EPS Steering Committee 2017 All rights reserved.
A Grant-in-Aid for Publication of Scientific Research Results (251001) from Japan
Society for the Promotion of Science is used for printing.

Contents
Special issue “Science of solar system materials examined from Hayabusa and future missions (II)”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tatsuaki Okada, Richard P. Binzel, Harold C. Connolly Jr., Toru Yada and Keiji Ohtsuki
Adhering grains and surface features on two Itokawa particles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E. Dobrică and R. C. Ogliore
Miniature lightweight X-ray optics (MiXO) for surface elemental composition mapping of asteroids and comets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Jaesub Hong, Suzanne Romaine and The MiXO teamCharacterising the CI and CI-like carbonaceous chondrites using thermogravimetric analysis and infrared spectroscopy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ashley J. King, Jake R. Solomon, Paul F. Schofield and Sara S. Russell
Amino acid compositions in heated carbonaceous chondrites and their compound-specific nitrogen isotopic ratios. . . . . . . . . . . . . . . . . . . . . . . . . . . . Queenie Hoi Shan Chan, Yoshito Chikaraishi, Yoshinori Takano, Nanako O. Ogawa and Naohiko Ohkouchi
On the effect of emergence angle on emissivity spectra: application to small bodies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alessandro Maturilli, Jörn Helbert, Sabrina Ferrari and Mario D’Amore
Characterization of asteroid analogues by means of emission and reflectance spectroscopy in the 1- to 100-µm
spectral range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alessandro Maturilli, Jörn Helbert, Sabrina Ferrari, Björn Davidsson and Mario D’Amore

1
6
6
7
7
8
8

Cover image: (left) Okada, T. et al., Earth, Planets and Space 2015, 67:116 Doi: 10.1186/s40623-015-0235-x;(right, ab) Dobrică, E. et al., Earth, Planets and Space 2016, 68:21 DOI: 10.1186/s40623-016-0391-7