Biosignature modification in the Oxia Planum region.

欧空局的ExoMars 2020罗莎琳德·富兰克林火星车预计将于2021年年中登陆火星，主要目标是寻找生命迹象。选定了一个着陆点，奥夏平原，那里含有丰富的粘土矿物，表明过去的环境受到了水蚀变[1-3]。以前的水的存在可能表明这一地区曾经是宜居的，但留下的任何生物特征(生命的地球化学指标)可能已经被随后的表面处理所改变，甚至被抹去，例如撞击陨石坑、干燥和成岩水蚀变

ESA's ExoMars 2020 Rosalind Franklin rover is expected to land on Mars in mid-2021, with a primary objective to search for signs of life. A landing site, Oxia Planum, has been selected that is rich in clay minerals, indicative of an environment that has been subjected to aqueous alteration in the past [1-3]. The prior presence of water may indicate that this region was once habitable, but any biosignatures (geochemical indicators for life) left behind may have been modified or even obliterated by subsequent surface processing, such as impact cratering, desiccation and diagenetic aqueous alteration