Abstract:
The key building blocks for life on Mars could be preserved within potentially habitable paleo-depositional settings with their detection possible by utilizing mid-infrared spectroscopy; however, a definite identification and confirmation of organic or even biological origin will require the samples to be returned to Earth. In the present study, Fourier-transform infrared (FTIR) spectroscopic techniques were used to characterize both mineralogical and organic materials within Mars dust simulant JSC Mars-1 and ancient Antarctic cyanobacterial microbial mats from 1901 to 1904 Discovery Expedition. When FTIR spectroscopy is applied to cyanobacterial microbial mat communities, the resulting spectra will reflect the average biochemical composition of the mats rather than taxa-specific spectral patterns of the individual organisms and can thus be considered as a total chemical analysis of the mat colony. This study also highlights the potential difficulties in the detection of these communities on Mars and which spectral biosignatures will be most detectable within geological substrates. Through the creation and analysis of a suite of dried microbial mat material and Martian dust simulant mixtures, the spectral signatures and wavenumber positions of CHx aliphatic hydrocarbons and the C-O and O-H bands of polysaccharides remained detectable and may be detectable within sample mixtures obtained through Mars Sample Return activities.
摘要:
火星上生命的关键组成部分可以保留在潜在的可居住的古沉积环境中,并可以利用中红外光谱进行检测;但是,确定和确认有机甚至生物来源将需要将样品返回地球。在本研究中,从1901年到1904年,使用傅立叶变换红外(FTIR)光谱技术来表征火星尘埃模拟物JSCMars-1和古代南极蓝细菌微生物垫中的矿物学和有机材料。当FTIR光谱应用于蓝藻微生物垫群落时,所得到的光谱将反映垫的平均生化组成,而不是单个生物体的分类单元特定的光谱模式,因此可以认为是垫菌落的总化学分析。这项研究还强调了在火星上探测这些群落的潜在困难,以及在地质基底中最容易探测到哪些光谱生物特征。通过创建和分析一套干燥的微生物垫材料和火星粉尘模拟混合物,CHx脂肪烃的光谱特征和波数位置以及多糖的C-O和O-H带仍然可检测到,并且可以在通过火星样品返回活动获得的样品混合物中检测到。