The Geological History of Valles Marineris, Mars

火星是太阳系中最像地球的行星，它也受到地球上许多地质过程的影响。火山活动、风蚀、水驱动的过程和冰川都在塑造火星表面方面发挥了作用。长期以来，这种相似性激发了人类的想象力，了解火星的地质历史一直是一个重要的目标。由于缺乏板块构造，火星表面保留了行星进化的早期阶段，而我们在地球上很容易接触到。目前美国宇航局好奇号火星车在大约36亿年历史的盖尔陨石坑内的主要目标是通过调查陨石坑中的分层沉积物来调查火星是否有一个能够支持生命的环境。水手谷是一个长4000公里，宽400公里，深达10公里的连接裂缝系统，与地球上的大型裂谷相比。这些裂缝部分被厚达8公里的层状沉积物填满，与盖尔环形山的沉积物相似。在这个项目中，我们研究了这个裂口系统是如何形成的，每个裂口是如何被层状沉积物填充的，以及它们随后被侵蚀的机制。了解充填和侵蚀机制的本质可以解决重要的环境因素，如水或冰的可用性。我们的技术是将数字图像与分辨率低至1米/像素的数字地形模型相结合。这使我们能够在3D中测量小的特征。对于层状矿床的调查，这些信息将由现有轨道高光谱传感器的矿物学观测加以补充。我们还将能够利用“好奇号”对盖尔内部分层沉积物进行的化学分析和颗粒尺度观测的结果，并将它们应用到我们能够在水手谷进行的更大规模观测中。这项研究将有助于更好地了解火星的早期地质历史和环境状况。这反过来又增强了我们对类地行星早期演化的理解。

Mars exhibits the most Earth-like conditions of all planets within our solar system and is affected by many of the same geological processes found on Earth. Volcanism, wind erosion, water-driven processes and glaciers have all played a role in shaping the surface of Mars. This similarity has inspired mankind's imagination for a long time and understanding the geological history of Mars has been an important goal. Because of the lack of plate tectonics, the Martian surface preserves an earlier stage of planetary evolution than we can easily access on Earth. The primary goal of the current NASA Curiosity rover mission within the ~3.6 billion year old Gale crater is to investigate whether Mars had an environment able to support life by investigating layered deposits in that crater. Valles Marineris, a 4000 km long, 400 km wide and up to 10 km deep system of linked chasms, which has been compared to large rift valleys on Earth. The chasms are partially filled with layered deposits up to 8 km thick that are similar to those in Gale Crater. In this project we investigate how this chasm system formed, how each chasm was filled with layered deposits and by what mechanism they were subsequently eroded. Understanding the nature of the mechanism for filling and erosion addresses important environmental factors such as the availability of water or ice. Our technique is to combine digital imagery with digital terrain models with resolutions as low as 1 m/pixel. This allows us to measure small features in 3D. For investigation of layered deposits this information will be supplemented by mineralogical observations from existing orbiting hyperspectral sensors. We will also be able to use the results of the chemical analyses and grain scale observations obtained by Curiosity on layered deposits within Gale and apply them to the larger scale observations we are able to make in Valles Marineris. This research will result in a better understanding of the early geological history and of the environmental conditions of Mars. This in turn enhances our understanding of the early evolution of terrestrial planets.