Geophysical Research Letters

An explanation of bright areas inside Shackleton Crater at the Lunar South Pole other than water-ice deposits

Authors

  • Junichi Haruyama,

    Corresponding author
    1. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa, Japan
    • Corresponding author: J. Haruyama, Institute of Space and Astronautical Science, Space Exploration Center, Japan Aerospace Exploration Agency, 3-1-1 Yoshino-dai, Chuo-ku, Sagamihara, Kanagawa 252-5210, Japan. (haruyama.junichi@jaxa.jp).

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  • Satoru Yamamoto,

    1. Center for Environmental Measurement and Analysis, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
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  • Yasuhiro Yokota,

    1. Center for Environmental Measurement and Analysis, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
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  • Makiko Ohtake,

    1. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa, Japan
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  • Tsuneo Matsunaga

    1. Center for Environmental Measurement and Analysis, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
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Abstract

[1] Whether water molecules of cometary and/or solar wind origin migrated to and accumulated in cold permanently shadowed areas at the lunar poles has long been debated from the perspective of scientific interest and expectations for future utilization. Recently, high reflectance condition was observed inside the lunar South Pole Shackleton Crater for the 1064.4 nm of the Lunar Orbiter Laser Altimeter on the Lunar Reconnaissance Orbiter, and the high reflectance was explained to perhaps be due to a surface frost layer in excess of 20% water-ice. Here we investigate the crater with the Selenological Engineering Explorer Multi-band imager that has nine bands in the visible to near-infrared range, including a 1050 nm band (62 m/pixel resolution). Part of the illuminated inner wall of Shackleton Crater exhibits high reflectance at 1050 nm but also exhibits the diagnostic 1250 nm spectral absorption, a signature that is consistent with naturally bright purest anorthosite.

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