Q&A Session for ApplicantsJune 18, 2024 21:00(JST)-First Accurate Estimate of Water
Content in C-type Asteroid

Abundant “primary” phyllosilicate but
no terrestrial alteration products (e.g.,hydrous sulfate)

TG-MS data of Ryugu and CI chondrite (Ivuna) (Yokoyama+ 2023)

A variety of observations for thewater/rock/organic reaction

Ryugu

Ivuna (CI)(Nakamura E+ 2022; Nakamura T+ 2023; Yabuta+ 2023)

Fluid inclusion~7 wt% indigenous water~5 wt% carbon (carbonate & organics)
High (~13-20 %) water contents in carbonaceous meteorites due toalteration on Earth
Image credit : JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba
Institute of Technology, Meiji University, University of Aizu, AIST.

1μm

framboidal magnetite

Phyllosilicate
2Carbonate
Magnetite (Ito+ 2022)

100 μm

20,000 Types of Organic Molecules
Found in Ryugu Sample
Amino acids detected in the Ryugu sample (modified after Naraoka+ 2023)

A variety of observations for thewater/rock/organic reaction
Glycine

Alanine(Yabuta+ 2023; Nakamura E+ 2022; Ito+ 2022)

Isovaline

Composite AFM-IR images
Yabuta+ 2023

Racemic mixture,indicative of abiotic origin

Green: Phyllosilicate
Reddish: Organics

3Image credit : JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba
Institute of Technology, Meiji University, University of Aizu, AIST.

Ryugu Represents the Solar Abundance (~CI chondrite)
without terrestrial alteration
Elemental abundance of Ryugu normalized to CI (Yokoyama+ 2023)
contamination by projectile

Notes:• Compositional variations are due tosample heterogeneity

CI chondrite = 1.0±0.1

4Image credit : JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba
Institute of Technology, Meiji University, University of Aizu, AIST.

Chemical heterogeneity in Ryugu samples
Aggregate samples(~25 mg)

Small particles(0.2–3 mg)

5 mm

5 mm

Data source:
Yokoyama et al (submitted)
Yokoyama et al. (2023)
Nakamura E. et al. (2022)
Ito et al. (2022)

Small Ryugu particles are heterogeneous for some elements (nugget effect)Ryugu Reference Project
Background◼ The Ryugu sample is unique in that it resembles the CI chondriteand represents Solar abundances in chemistry with minimalterrestrial contamination.
◼ The HYB2 initial analysis and Phase 2 curation teams found achemical variation within the studied "small (<30 mg)" fractions.
Moreover, these fractions are insufficient to analyze key isotopes.
◼ JAXA launches the Ryugu Reference Project (RRP).

Key discussion points◼ How much do we need to guarantee the solar abundance? Eventhe grams of homogenous Ryugu powder may not represent theRyugu bulk or the Solar abundance.

Team structure
Ryugu Reference Project Measurement Definition Team1) Define the scientific goals and objectives of the Ryugu Reference Project (e.g., list of elements,isotopes, and chemical species in the Ryugu Reference; accuracy and precision required for theRyugu Reference).
2) Recommend the analytical protocols that meet the project requirements (e.g., amount of
Ryugu sample, uncontaminated powdering process, instrumentation, number of analysis runs).

3) File an MDT report with JAXA to publish as a community white paper.

Ryugu Reference Project Consortium
1) Measure allocated fractions and provide the data to the JAXA database; target
elements/species/isotopes for the individual members are defined by the MDT’s white paper2) Contribute to data interpretation and write a consortium paper.

Call for Measurement Definition Team (MDT)⚫ Purpose◼ Report the white paper on sample selection, processing,and analysis for the Ryugu Reference Project⚫ Measurement Definition Team Organization◼ ~10-15 experts in petrology, mineralogy,
cosmochemistry, organic geochemistry, theoreticalresearchers on Solar System formation & curation◼ A chair will be selected from the successful applicants◼ Program Executive (JAXA curation)◼ Facilitation & technical support (JAXA curation)

How to apply?

Today's video (explanation only) and Q&A(PDF) will be available here at a later date.

Please read the guidebook carefully andsubmit your application (using thetemplate) and CV.

Contact us:
jaxa-curation-rrp@jaxa.jp

Key milestones for the applications for Ryugu Reference ProjectMeasurement Definition Team (RRP-MDT)- Call for applications: June 6, 2024
- Submission of application due: 12:00(JST), July 5, 2024
- Decision announcement: No earlier than July, 2024 (TBD)- Expected completion of tasks: ~6 months after selections