Chanover N J, Uckert K, Voelz D G, Boston P
Astronomy Department New Mexico State University Las Cruces NM USA.
Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA.
Earth Space Sci. 2023 Feb;10(2):e2022EA002370. doi: 10.1029/2022EA002370. Epub 2023 Feb 10.
Planetary caves are desirable environments for the search for biosignatures corresponding to extant or extinct extraterrestrial life due to the protection they offer from surface-level solar radiation and ionizing particles. Near-infrared (NIR) reflectance spectroscopy is one of a multitude of techniques that, when taken together, can provide a comprehensive understanding of the geomicrobiology in planetary subsurface regions. To that end, we developed two portable NIR spectrometers that employ acousto-optic tunable filters and demonstrated them in three geochemically distinct cave environments. The instruments were deployed both as stand-alone spectrometers positioned against the targets manually and as a component of an instrument payload mounted on a quadruped robot capable of vertical excursions of several meters. In situ measurements of calcium carbonates, sulfates, metal oxides, and microbial colonies and mats revealed spectral signatures that enable a distinction between the targets of interest and the underlying substrates. The ruggedness and portability of the instruments, and their low size, weight, and power, spectral agility, and active illumination make AOTF-based spectrometers ideally suited for studies of planetary caves.
由于行星洞穴能够保护内部免受地表太阳辐射和电离粒子的影响，因此是寻找与现存或已灭绝的外星生命相关的生物特征的理想环境。近红外（NIR）反射光谱法是众多技术之一，这些技术结合起来可以全面了解行星地下区域的地质微生物学。为此，我们开发了两台采用声光可调滤光片的便携式近红外光谱仪，并在三种地球化学特征不同的洞穴环境中进行了演示。这些仪器既可以作为独立的光谱仪手动对准目标进行部署，也可以作为仪器载荷的一部分安装在能够进行数米垂直移动的四足机器人上。对碳酸钙、硫酸盐、金属氧化物以及微生物菌落和菌毯的现场测量揭示了光谱特征，这些特征能够区分感兴趣的目标和下面的基质。仪器的坚固性、便携性、小尺寸、低重量、低功耗、光谱灵活性以及主动照明特性，使得基于声光可调滤光片的光谱仪非常适合用于行星洞穴研究。
