Raman Biosignatures for Astrobiology Missions

火星以及木星和土星的卫星（木卫二和土卫二）是我们太阳系中寻找生命的下一个目标。新的生命探测仪器确实准备在2020年被送往火星（搭载在欧洲航天局/俄罗斯航天局的ExoMars2020和美国宇航局的Mars2020探测器上），甚至可能更远。其中，光谱方法如拉曼或红外是有前途的技术，可以提供矿物学背景和生物特征识别的见解。然而，为了支持和正确解释光谱数据，以及指导未来的生命探测任务，更好地了解可能的宜居环境和潜在的可探测生物特征是至关重要的。在过去几年中，广泛的实地和实验室调查的重点是证明这些技术在描述与火星有关的矿物和生物样品方面的能力，但很少评估在类火星或类空间条件下可能出现的生物特征退化。因此，拟议项目的目标是：扩大我们对通过拉曼光谱方法可探测到的来自类火星和冰冷的类月球环境的极端微生物的潜在生物特征的知识，并评估其遗骸在行星环境中的可探测性。为此，我们将获得来自不同陆地模拟场的生物样本，如熔岩管、阿塔卡马沙漠、南极洲等。通过位于柏林的德国航空航天中心（DLR）的行星研究所领导的欧空局BIOMEX和BIOSIGN项目，这些样本已经并将被暴露在真实空间和模拟条件下，接近火星和冰冷的卫星的行星条件。此外，我们将首次能够在测量过程中分析类太空或类火星环境条件对所获得的拉曼光谱的影响，这要归功于DLR和法国orlsamans的两个国家科学研究中心（CNRS）团队的合作机构中世界上独一无二的腔室。这些装置将使我们能够评估在高紫外线或高能粒子照射期间选定的生物特征保存潜力。因此，拟议的项目将利用DLR、CNRS orlsamans内部现有的基础设施、样品、合作和仪器，并通过不同的正在进行的项目和实验，选择和表征一大类潜在的生物和生物特征。基于这些能力，我提出的研究是完全新颖的，非常及时，对即将到来的机器人火星任务至关重要。

Mars and the Jovian and Saturnian moons (Europa and Enceladus) are the next targets to search for life in our Solar System. New life detection instruments are indeed ready to be sent to Mars in 2020 (onboard ESA/Roscomos’s ExoMars2020 and NASA’s Mars2020 rovers) and possibly further. Among them, spectroscopy methods such as Raman or infrared are promising techniques that can give insights on both the mineralogical context and the identification of biosignatures. However, to support and interpret spectroscopic data correctly, as well as to guide future life detection missions, a better understanding of possible habitable environments and potentially detectable biosignatures is of paramount importance. Extensive field and laboratory investigations focused in the last years on demonstrating the capabilities of such technologies to characterize both mineral and biological samples of relevance to Mars but very few assessed potential biosignatures degradation under Mars-like or space-like conditions. The objectives of the proposed project are thus: to expend our knowledge of the potential biosignatures of extremophilic organisms from Mars-like and icy moon-like environments detectable by Raman spectroscopy methods and to assess the detectability of their remains in the context of planetary environments. We will, for that, have access to biological samples from diverse terrestrial analogue field sites such as lava tubes, the Atacama Desert, Antarctica and others. And to samples which were, and will be, exposed to real space and simulated conditions approaching the planetary conditions of Mars and the icy moons via the ESA projects BIOMEX and BIOSIGN, led by the Institute of Planetary Research of the German Aerospace Center (DLR) in Berlin. In addition, we will, for the first time, be able to analyze the influence of space-like or Mars-like environmental conditions on the obtained Raman-spectra during the measurements thanks to world-unique chambers present at DLR and partner institutions in two Centre National de la Recherche Scientifique (CNRS) teams in Orléans (France). These setups will allow us to assess selected biosignatures preservation potential during, for instance, high UV or energetic particle irradiation. The proposed project will therefore take advantage of existing infrastructures, samples, collaborations and instrumentation available internally at DLR, at the CNRS Orléans and through the different ongoing projects and experiments, in order to select and characterize a large class of potential organisms and biosignatures with different Raman instruments. Based on these capacities, my proposed study is entirely novel, extremely timely and of utmost importance for the upcoming robotic missions to Mars.