Heldmann J L, Schurmeier L, McKay C, Davila A, Stoker C, Marinova M, Wilhelm M B
1 NASA Ames Research Center , Division of Space Sciences and Astrobiology, Moffett Field, California.
Astrobiology. 2014 Feb;14(2):102-18. doi: 10.1089/ast.2013.1103. Epub 2014 Feb 7.
Midlatitude ground ice on Mars is of significant scientific interest for understanding the history and evolution of ice stability on Mars and is relevant for human exploration as a possible in situ resource. For both science and exploration, assessing the astrobiological potential of the ice is important in terms of (1) understanding the potential for life on Mars and (2) evaluating the presence of possible biohazards in advance of human exploration. In the present study, we review the evidence for midlatitude ground ice on Mars, discuss the possible explanations for its occurrence, and assess its potential habitability. During the course of study, we systematically analyzed remote-sensing data sets to determine whether a viable landing site exists in the northern midlatitudes to enable a robotic mission that conducts in situ characterization and searches for evidence of life in the ice. We classified each site according to (1) presence of polygons as a proxy for subsurface ice, (2) presence and abundance of rough topographic obstacles (e.g., large cracks, cliffs, uneven topography), (3) rock density, (4) presence and abundance of large boulders, and (5) presence of craters. We found that a suitable landing site exists within Amazonis Planitia near ground ice that was recently excavated by a meteorite impact.
火星中纬度地面冰对于理解火星上冰稳定性的历史和演化具有重大科学意义,并且作为一种可能的原位资源与人类探索相关。对于科学研究和探索而言,评估冰的天体生物学潜力在以下两方面都很重要:(1)了解火星上存在生命的可能性;(2)在人类探索之前预先评估可能存在的生物危害。在本研究中,我们回顾了火星中纬度地面冰的证据,讨论了其形成的可能原因,并评估了其潜在的宜居性。在研究过程中,我们系统地分析了遥感数据集,以确定在北中纬度地区是否存在一个可行的着陆点,以便开展一项进行原位特征描述并寻找冰中生命证据的机器人任务。我们根据以下因素对每个地点进行了分类:(1)多边形的存在作为地下冰的代理指标;(2)粗糙地形障碍物(如大裂缝、悬崖、地形不平)的存在和丰富程度;(3)岩石密度;(4)大石块的存在和丰富程度;(5)陨石坑的存在。我们发现,在亚马逊平原靠近最近因陨石撞击而被挖掘出地面冰的地方存在一个合适的着陆点。