Raman Biosignatures for Astrobiology Missions

火星、木星和土星的卫星（木卫二和土卫二）是在太阳系中寻找生命的下一个目标。新的生命探测仪器确实已经准备好在2020年被送往火星（欧空局/Roscomos的ExoMars 2020和NASA的Mars 2020漫游者），甚至可能更远。其中，光谱学方法，如拉曼或红外是有前途的技术，可以提供洞察矿物学背景和生物特征的识别。然而，为了正确地支持和解释光谱数据，以及指导未来的生命探测任务，更好地了解可能的可居住环境和潜在的可检测生物特征至关重要。在过去几年中，广泛的实地和实验室调查侧重于证明这类技术有能力确定与火星有关的矿物和生物样本的特征，但很少评估在类似火星或类似太空的条件下可能发生的生物特征退化。因此，拟议项目的目标是：扩大我们对可通过拉曼光谱法探测到的来自火星和冰冷的月球环境的嗜极端生物的潜在生物特征的了解，并评估其遗骸在行星环境中的可探测性。为此，我们将获得来自熔岩管、阿塔卡马沙漠、南极洲等不同陆地模拟野外地点的生物样本。以及通过柏林德国航空航天中心行星研究所领导的欧空局项目BIOMEX和BIOSIGN，暴露于和将暴露于接近火星和冰冷卫星行星条件的真实的空间和模拟条件的样品。此外，我们将首次能够分析类太空或类火星环境条件对测量期间获得的拉曼光谱的影响，这要归功于DLR的世界独特的腔室以及法国奥尔良国家科学研究中心（CNRS）两个团队的合作机构。这些设置将使我们能够评估选定的生物特征保存潜力，例如，高紫外线或高能粒子照射。因此，拟议的项目将利用德国航天中心、法国国家科学研究中心奥尔良站内部现有的基础设施、样本、合作和仪器，并通过正在进行的不同项目和实验，利用不同的拉曼仪器选择和鉴定一大类潜在的生物体和生物特征。基于这些能力，我提出的研究是完全新颖的，非常及时的，对即将到来的火星机器人任务至关重要。

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.