NAOJ Symposium 2019 | December 13, 2019

A new perspective of Solar
System science with close
collaboration with Astronomy
Shogo Tachibana, U. Tokyo / ISAS, JAXA(c) JAXA, Univ. Tokyo, Kochi Univ., Rikkyo Univ., Nagoya Univ., Chiba Inst. Tech.,
Meiji Univ.. Univ. Aizu, AIST, DLR, CNESS | all the images in this talk

1. Solar System science explores theformation and evolution of the Solar Systemincl. the life on the Earth, which is a part ofthe evolution of the Galaxy
2. Many of celestial bodies in the Solar System
are reachable by spacecraft that provide
geophysical and geochemical information of
the bodies and even samples for us

3. Extraterrestrial materials incl. the samples
returned by spacecraft tell what happened intheir parent bodies and/or in the Solar System(in case of meteorites, we even do not what theparent bodies were!), but do not tell in detail

how the Solar System architecture formed at
the beginning

4. Astronomical observation should help us tounderstand how the Solar-System dynamicallyand chemically evolved to the present state, asa part of the Galactic evolution, by combining
with the extraterrestrial material research2724211815

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1. Solar System science explores theformation and evolution of the Solar Systemincl. the life on the Earth, which is a part ofthe evolution of the Galaxy

Abundance (Si=106)

Solar abundance of nuclides
The Solar System is madeof nuclides synthesizedin various types of stars

Mass number

Lodders (2003)

SolarAbundance

Universality ofSolar abundanceHitomi Collaboration (2017)

Short- and long-lived radionuclides may
record the Solar System forming environmentgasSFR

10Be

232Th

26Al235U36Cl

238U

41Ca
53Mn

Fujimoto+ (2018)
60Fe

60Fe

26Al

92Nb
107Pd
129I
182Hf
-1.5 -1 -0.5 0 0.5 1

1.5 -1.5 -1 -0.5 0 0.5 1

1.5

kpc

244Pu

The Solar System is made of nuclides
synthesized in various types of stars

destruction /metamorphism

circumstellar
dust (stardust)

Molecularclouds
Solar System

Protoplanetary disk

Presolar grains with isotope
anomalies are real ‘stardust’Single crystal Corundum (α-Al2O3)
from a low-to-intermediate AGB star0)1(1rhombohedral
(011)

(101)

Takigawa+ (2018)

Graincollision?

Mineralogy revealed 13-micron feature
as vapor grown corundumSingle crystal Corundum (α-Al2O3)
from a low-to-intermediate AGB star)011(rhombohedral(011)(101)

Takigawa+ (2018)

Graincollision?

13-micron feature = vapor-grown corundum
Takigawa+ (2015)

ALMA first observed alumina-dust forming
region around an O-rich evolved star
Takigawa+ (2017)
29SiO

AlO
W Hydrae

3 R*
Ohnaka+ (2016)

Condensed aluminum oxide dust accelerates the stellar
wind and prevents the efficient formation of silicate dust

2. Many of celestial bodies in the Solar System
are reachable by spacecraft that provide
geophysical and geochemical information of
the bodies and even samples for us

Hayabusa2 visited Ryugu

Watanabe+ (2019), Sugita+ (2019), Kitazato+ (2019)

OH signature at 2.7 micron
Shocked CM2Heated CI1Kitazato+ (2019)OSIRIS-REx has been investigating Bennu

OH signature at 2.7 micron
Bennu

Shocked CM2Heated CI1

Hamilton+ (2019)

Dehydration?
Weak aqueous alteration?
Kitasato+ (2019)

Rosetta sniffed organic molecules from 67P/C-G
H2O

80.92 (%)

CH40.70

CO1.09HCNCH3NH21.061.19

CH3CN

0.55

CH3CHO

1.01

C2H5NH2

0.72

HNCO

HCONH2CH3NCO

0.47

3.73
3.13

CH3COCH3

1.02

CH3CONH2

2.20

CH2(OH)CH2(OH)0.79

C2H5CHOCH2OHCHO

0.44

0.98

Comet
67P/C-GChemical diversity of molecular clouds –likely to be related to star formation process

Modified from Yamamoto (2017)

Chemistry of protoplanetary disks isinherited from molecular clouds
H2CO, SO,(CH3OH)
300‒100 K

SO, (CH3OH)~100 K

CCH, c-C3H2,CS, H2CO
~30 K

Sakai+ (2013)

Go farther
Water, Organics
More pristine materialsChemical diversity in Solar System organics

67P/C-G(Fray+, 2017)

Initial chemistry ofthe Solar System?

UCAMMs (Engrand+, 2018)

Yabuta+ (2017)

Spacecraft go farther to the scale comparable
to astronomical observation
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3. Extraterrestrial materials incl. the samples
returned by spacecraft tell what happened intheir parent bodies and/or in the Solar System(in case of meteorites, we even do not what theparent bodies were!), but do not tell in detail

how the Solar System architecture formed atthe beginning– When and where did the first solids
form in the Solar System?
– What is the Earth made of?

First solids in the Solar System
CAIs (Calcium-, Aluminum-rich inclusions)
Oldest solids in the Solar
System, consisting of minerals
enriched in refractoryelements (Ca, Al, Ti etc.)

First solids in the Solar System
CAIs (Calcium-, Aluminum-rich inclusions)
Oldest solids in the Solar
System, consisting of minerals
enriched in refractoryelements (Ca, Al, Ti etc.)

They formedat high temperatures

When and where did the firstsolids form in the Solar System?

First solids in the Solar System
CAIs (Calcium-, Aluminum-rich inclusions)
Oldest solids in the Solar
System, consisting of minerals
enriched in refractoryelements (Ca, Al, Ti etc.)

They formed
4.567 billion years ago(Amelin+ 2002; Connelly+ 2012)

When and where did the firstsolids form in the Solar System?

Origin and Evolutionof the Solar System

Molecular
Clouds

4.567Ga?
4.567Ga?

Protoplanetary Disk

4.567Ga?

Small bodies

Planets

EvolvedStarsAstronomical & Cosmochemical timelines

Nittler & Ciesla (2016)

First solids in the Solar System
CAIs (Calcium-, Aluminum-rich inclusions)
Oldest solids in the Solar
System, consisting of minerals
enriched in refractoryelements (Ca, Al, Ti etc.)

Let us look at othersystems!

When and where did the firstsolids form in the Solar System?

High-temperature gas around a young star

Orion Source I
A massive young star candidate(5–7 MSUN: Plambeck & Wright 2016;15 MSUN: Ginsburg+ 2018)

High-temperature gas around a young star
CAIs (Calcium-, Aluminum-rich inclusions)
AlO 497 GHz(N=13–12)

AlO 650 GHz(N=17–16)

Tachibana+ (2019)

High-temperature gas around a young starOrionSource I

diskoutflow

First obs. of spatial distribution ofAlO 497 GHz emission around a YSO

100 auTachibana+ (2019)

High-temperature gas around a young star
Condensation front ofrefractory minerals?

AlO

SiO

Sun-likestars?
Hirota+ (2017)

Tachibana+ (2019)

First solids in the Solar System
CAIs (Calcium-, Aluminum-rich inclusions)

Further obs. of Sun-likeyoung stars combined w/
CAI analysis and lab.
experiments to constrain“time 0” of the Solar System

When and where did the firstsolids form in the Solar System?

First solids in the Solar SystemCAIs (Calcium-, Aluminum-rich inclusions)Hydrogen pressure at theCAI forming region –10–4~10–5 bar (1015-16 cm–3)
Mendybaev+ 2006;
Kamibayashi+ in prep.

When and where did the firstsolids form in the Solar System?

Oxygen isotope evolution
Three isotopes:
16O, 17O, 18O

Oxygen isotope evolution
What is the Earth made of?
Earth is made of dust with nonSolar O isotopes, but why wasdust non-Solar?

16O-poor

H2O

16O-rich

CO

McKeegan+ (2011)

Oxygen isotope exchange reaction
H216O H217O H218O
17O, 18O-rich

Dust

C16O C17O C18O
17O, 18O-poore.g., Yurimoto & Kuramoto (2004)

Oxygen isotope exchange experiments
Gold-mirror vacuum furnace

H218O

Starting material:
Amorphous forsterite & enstatite (~80 nm)
T: 803, 853, 883, 953, 1023, 1123 K
PH2O: 1x10–7, 3x10–6 bart: 0 – 336 h

Yamamoto & Tachibana (2018); Yamamoto, Tachibana+ (2018, 2019)O isotope exchange b/w amorphous silicate & H2O
structural O + H2*O ⇋ *OH + OH ⇋ structural *O + H2O

Yamamoto & Tachibana (2018); Kuroda, Tachibana+ (2018);

O isotope exchange b/w amorphous silicate & H2O
Exchangefraction

amorphous olivine(Mg2SiO4)

1

amorphous pyroxene(MgSiO3)
D = (2.2 ± 0.03) × 10-22 m2 sec-1

883 K0.8

D = (4.4 ± 0.8) × 10-22 m2 sec-1

853 K
D = (1.9 ± 0.8) × 10-22 m2 sec-1

0.6

D = (6.9 ± 0.1) × 10-23 m2 sec-1

1003 K

953 K
923 K

0.4

D = (4.3 ± 0.06) × 10-23 m2 sec-1

803 K
0.200

D = (4.9 ± 0.6) × 10-23 m2 sec-1

50

100150200250300 350 050

duration (hour)

100150 200 250

300 350 400

O isotope exchange b/w amorphous silicate & H2O
0.08 micron-sized dust
Crystallization ofamorphous FoO(PH2O=3x10–6 bar)
am isoto
orp pic
ho ex
us ch
Fo angan e bd H /w
2O

500 K for ~1My
600 K for ~10 ky
700 K for ~100 yr

Yamamoto, Tachibana+ (2018, 2019)

O isotope exchange b/w amorphous silicate & H2O
0.08 micron-sized dust
Crystallization ofamorphous FoO(PH2O=3x10–6 bar)
am isoto
orp picho ex
us ch
Fo angan e bd H /w
2OO-isotope exchange b/w sub-micron
amorphous silicates and H2O occurs
within 1 Myr at >500 K

Yamamoto, Tachibana+ (2018, 2019)

Oxygen isotope evolution
What is the Earth made of?
16O-poor

Earth is made of dust with nonSolar O isotopes, but why was
dust non-Solar?

H2O

16O-rich

COMcKeegan+ (2011)

Oxygen isotope evolution
What is the Earth made of?
Earth is made of dust with nonSolar O isotopes, but why wasdust non-Solar?

Oxygen isotope exchange reaction
Did all the dust experience heating at above 500 K?
Are there any residual 16O-rich pristine dust anywherein the Solar System?
return?
Ryugu? Another comet sample

Oxygen isotope evolution
Isotopicallyhomogenized
H2O and CO

16O-poor H2O
16O-rich CO~500 K

Oxygen isotope
homogenization-line?

4. Astronomical observation should help us tounderstand how the Solar-System dynamicallyand chemically evolved to the present state, asa part of the Galactic evolution, by combining
with the extraterrestrial material research
2724

21

1815

Astronomical observation

12963

log10 L [m]-3-6-90ET materialSpacecraft exploration