Details

Autor(en) / Beteiligte

• Sugahara, Haruna
• Takano, Yoshinori
• Karouji, Yuzuru
• Kumagai, Kazuya
• Yada, Toru
• Ohkouchi, Naohiko
• Abe, Masanao

Titel

Amino acids on witness coupons collected from the ISAS/JAXA curation facility for the assessment and quality control of the Hayabusa2 sampling procedure

Ist Teil von

• Earth, planets, and space, 2018-12, Vol.70 (1), p.1-10, Article 194

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2018

Quelle

SpringerLink

Beschreibungen/Notizen

• The Hayabusa2 mission aims to obtain pristine samples from a near-Earth carbonaceous-type (C-type) asteroid, 162173 Ryugu, and return them to Earth. One of the scientific goals of the mission is to understand the origin and evolution of organic materials through the interactions between water and minerals in the early solar system. Thus, organic materials are the main focus of the analysis on the returned samples. The analysis of extraterrestrial organic materials, however, requires great care to avoid the introduction of terrestrial contaminants and artefacts to the samples. To investigate the potential for contamination, we performed an assessment through the amino acid analysis of witness coupons that were exposed in a clean chamber in an Institute of Space and Astronautical Science/Japan Aerospace Exploration Agency (ISAS/JAXA) curation room. In the study, the witness coupons were collected at different time periods, between 1 day and 1 month, to examine the accumulation rates of the contaminants. Seven common terrestrial amino acids (glycine, alanine, valine, leucine, isoleucine, proline, aspartic acid and glutamic acid) were detected on the witness coupons. Among them, glycine was found to be most abundant, with the highest concentration of 10 pmol/cm 2 detected on the day 7 witness coupon. Alanine was found in the next highest concentration, approximately one-third that of glycine. A time-dependent profile in terms of the increasing trend observed in the concentration from days 1 to 7 was found. The contaminants were considered to have multiple origins. Our results are similar to those reported by the National Aeronautics and Space Administration/Johnson Space Center (NASA/JSC) OSIRIS-REx team, which indicates that the quality control against terrestrial contaminants in our facility is at the same quantitative level as in their facility. The knowledge obtained on the contaminants in this study will provide important information for the curation procedure of the Hayabusa2-returned samples.