Plumes of Water Ice/Gas Mixtures Observed in the Lunar Polar Region
The presence of water condensation in the lunar polar region has been reported. However, the origin and amount of water remain unknown, and information on the migration mechanism of water is key for understanding the delivery of water to the Earth–Moon system. We herein report the first identificati...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad1be3 |
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| author | Makiko Ohtake Yusuke Nakauchi Satoshi Tanaka Mitsuo Yamamoto Keisuke Onodera Hiroshi Nagaoka Ryusuke Nishitani |
| author_facet | Makiko Ohtake Yusuke Nakauchi Satoshi Tanaka Mitsuo Yamamoto Keisuke Onodera Hiroshi Nagaoka Ryusuke Nishitani |
| author_sort | Makiko Ohtake |
| collection | DOAJ |
| description | The presence of water condensation in the lunar polar region has been reported. However, the origin and amount of water remain unknown, and information on the migration mechanism of water is key for understanding the delivery of water to the Earth–Moon system. We herein report the first identification of the migration process observed as localized and condensed plumes of water ice/gas mixtures ejected from the lunar surface to space in the polar region based on spectral data derived by SELENE/Kaguya. We identified water and other volatile absorption in 10,200 spectra at the nonpermanent shadowed region during the nighttime when no illumination reached the lunar surface, while nearly horizontal solar light at these regions could illuminate the sky. Ray-tracing analyses suggested that the majority of the observed volatile signal did not come from the lunar surface but from the sky (space). The majority of the identified plumes were observed at or near the hydrogen distribution reported previously. Volatile materials were repeatedly identified in some locations and most of the plume events did not coincide with the major meteoroid streams. Rather, more signals were identified during the winter season in each pole. The timing, duration, location, and temperature simulations all suggest that impact events cannot be their main origin, but rather the volatile sublimation from the subsurface (∼10 cm depth). Overall, it was revealed that the lunar polar region is active in terms of volatile migration, which is significant for understanding water delivery to the Earth–Moon system. |
| first_indexed | 2024-04-25T01:28:45Z |
| format | Article |
| id | doaj.art-210f4d8595c64b7fae7889854e3a5bc0 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-04-25T01:28:45Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-210f4d8595c64b7fae7889854e3a5bc02024-03-08T13:25:38ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01963212410.3847/1538-4357/ad1be3Plumes of Water Ice/Gas Mixtures Observed in the Lunar Polar RegionMakiko Ohtake0https://orcid.org/0000-0001-9464-3012Yusuke Nakauchi1https://orcid.org/0000-0002-3745-460XSatoshi Tanaka2https://orcid.org/0000-0002-4874-0417Mitsuo Yamamoto3Keisuke Onodera4https://orcid.org/0000-0003-4120-2437Hiroshi Nagaoka5https://orcid.org/0000-0001-8103-3872Ryusuke Nishitani6https://orcid.org/0000-0002-3763-0095The University of Aizu , Aizu-Wakamatsu, Fukushima, Japan ; makiko-o@u-aizu.ac.jpResearch Organization of Science and Technology, Ritsumeikan University , Kusatsu, Shiga, JapanInstitute of Space and Astronautical Science , Japan Aerospace Exploration Agency Sagamihara, Kanagawa, JapanInstitute of Space and Astronautical Science , Japan Aerospace Exploration Agency Sagamihara, Kanagawa, JapanEarthquake Research Institute, The University of Tokyo , Yayoi, Tokyo, JapanResearch Organization of Science and Technology, Ritsumeikan University , Kusatsu, Shiga, JapanHuman Spaceflight Technology Directorate, Japan Aerospace Exploration Agency Tsukuba , Ibaraki, JapanThe presence of water condensation in the lunar polar region has been reported. However, the origin and amount of water remain unknown, and information on the migration mechanism of water is key for understanding the delivery of water to the Earth–Moon system. We herein report the first identification of the migration process observed as localized and condensed plumes of water ice/gas mixtures ejected from the lunar surface to space in the polar region based on spectral data derived by SELENE/Kaguya. We identified water and other volatile absorption in 10,200 spectra at the nonpermanent shadowed region during the nighttime when no illumination reached the lunar surface, while nearly horizontal solar light at these regions could illuminate the sky. Ray-tracing analyses suggested that the majority of the observed volatile signal did not come from the lunar surface but from the sky (space). The majority of the identified plumes were observed at or near the hydrogen distribution reported previously. Volatile materials were repeatedly identified in some locations and most of the plume events did not coincide with the major meteoroid streams. Rather, more signals were identified during the winter season in each pole. The timing, duration, location, and temperature simulations all suggest that impact events cannot be their main origin, but rather the volatile sublimation from the subsurface (∼10 cm depth). Overall, it was revealed that the lunar polar region is active in terms of volatile migration, which is significant for understanding water delivery to the Earth–Moon system.https://doi.org/10.3847/1538-4357/ad1be3Earth-moon systemWater vaporLunar transient phenomenaEruptive phenomena |
| spellingShingle | Makiko Ohtake Yusuke Nakauchi Satoshi Tanaka Mitsuo Yamamoto Keisuke Onodera Hiroshi Nagaoka Ryusuke Nishitani Plumes of Water Ice/Gas Mixtures Observed in the Lunar Polar Region The Astrophysical Journal Earth-moon system Water vapor Lunar transient phenomena Eruptive phenomena |
| title | Plumes of Water Ice/Gas Mixtures Observed in the Lunar Polar Region |
| title_full | Plumes of Water Ice/Gas Mixtures Observed in the Lunar Polar Region |
| title_fullStr | Plumes of Water Ice/Gas Mixtures Observed in the Lunar Polar Region |
| title_full_unstemmed | Plumes of Water Ice/Gas Mixtures Observed in the Lunar Polar Region |
| title_short | Plumes of Water Ice/Gas Mixtures Observed in the Lunar Polar Region |
| title_sort | plumes of water ice gas mixtures observed in the lunar polar region |
| topic | Earth-moon system Water vapor Lunar transient phenomena Eruptive phenomena |
| url | https://doi.org/10.3847/1538-4357/ad1be3 |
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