2023-07-27 カリフォルニア大学バークレー校(UCB)
◆ガニメデの過酸化水素の観測は、帯電粒子が月の極域で化学反応を引き起こしていることを示し、イオの硫黄の煙の観測は火山活動と関連していることを明らかにしました。これらの発見は、太陽系の氷の天体の化学を理解するための重要な情報源となり、将来の宇宙探査に役立つ可能性があります。また、JWSTは他の惑星系の研究にも活用される予定です。
＜関連情報＞
- https://news.berkeley.edu/2023/07/27/james-webb-space-telescope-sees-jupiter-moons-in-a-new-light/
- https://www.science.org/doi/10.1126/sciadv.adg3724
ガニメデの極に存在する過酸化水素 Hydrogen peroxide at the poles of Ganymede
Samantha K. Trumbo,Michael E. Brown,Dominique Bockelée-Morvan,Imke de Pater,Thierry Fouchet,Michael H. Wong,Stéphanie Cazaux,Leigh N. Fletcher,Katherine de Kleer,Emmanuel Lellouch,Alessandro Mura,Olivier Poch ,Eric Quirico,Pablo Rodriguez-Ovalle,Mark R. Showalter,Matthew S. Tiscareno,Federico Tosi
Science Advances Published:21 Jul 2023
DOI:https://doi.org/10.1126/sciadv.adg3724
Abstract
Ganymede is the only satellite in the solar system known to have an intrinsic magnetic field. Interactions between this field and the Jovian magnetosphere are expected to funnel most of the associated impinging charged particles, which radiolytically alter surface chemistry across the Jupiter system, to Ganymede’s polar regions. Using observations obtained with JWST as part of the Early Release Science program exploring the Jupiter system, we report the discovery of hydrogen peroxide, a radiolysis product of water ice, specifically constrained to the high latitudes. This detection directly implies radiolytic modification of the polar caps by precipitation of Jovian charged particles along partially open field lines within Ganymede’s magnetosphere. Stark contrasts between the spatial distribution of this polar hydrogen peroxide, those of Ganymede’s other radiolytic oxidants, and that of hydrogen peroxide on neighboring Europa have important implications for understanding water-ice radiolysis throughout the solar system.
