Effects of extreme cold and aridity on soils and habitability: McMurdo Dry Valleys as an analogue for the Mars Phoenix landing site
Effects of extreme cold and aridity on soils and habitability: McMurdo Dry Valleys as an analogue for the Mars Phoenix landing site
复制标题
极端寒冷和干旱对土壤和宜居性的影响：麦克默多干谷与火星凤凰号着陆点的类似
作者：
L. Tamppari;Rachel M. Anderson;P. Archer;S. Douglas;S. Kounaves;C. Mckay;D. Ming;Quincy Moore;J. Quinn;Peter H. Smith;Shannon T. Stroble;A. Zent
摘要 麦克默多干谷是地球上最干燥、最寒冷的环境之一，非常类似于火星北部平原。在准备 2008 年凤凰城火星任务时，我们进行了一项跨学科调查，比较了湿润的泰勒谷下游 (TV) 土壤与寒冷、干燥的大学谷 (UV) 土壤的生物、矿物学、化学和物理特性。我们对从地表到冰面的每个地平线进行了分析。在电视中，粘土大小的颗粒分布和较少丰富的可溶性盐都表明水的垂直和可能的水平运输，并且微生物生物量较高。云母向短级层状硅酸盐的转变表明存在水风化。在紫外线下，盐、粘土大小的物质和生物质在地表附近更加丰富，表明水的向下移位最小。在超干旱地区首次确定了每个层位中存在微生物。在地表和冰面附近发现了较高的生物量，这可能代表当地环境更加温和。目前，水活度太低，无法支持凤凰城遗址的新陈代谢，但如果种群能够度过较长的休眠期（约 106 年），倾斜度的变化可能会产生更高的温度和足够的水活度以允许微生物生长。
Abstract The McMurdo Dry Valleys are among the driest, coldest environments on Earth and are excellent analogues for the Martian northern plains. In preparation for the 2008 Phoenix Mars mission, we conducted an interdisciplinary investigation comparing the biological, mineralogical, chemical, and physical properties of wetter lower Taylor Valley (TV) soils to colder, drier University Valley (UV) soils. Our analyses were performed for each horizon from the surface to the ice table. In TV, clay-sized particle distribution and less abundant soluble salts both suggested vertical and possible horizontal transport by water, and microbial biomass was higher. Alteration of mica to short-order phyllosilicates suggested aqueous weathering. In UV, salts, clay-sized materials, and biomass were more abundant near the surface, suggesting minimal downward translocation by water. The presence of microorganisms in each horizon was established for the first time in an ultraxerous zone. Higher biomass numbers were seen near the surface and ice table, perhaps representing locally more clement environments. Currently, water activity is too low to support metabolism at the Phoenix site, but obliquity changes may produce higher temperatures and sufficient water activity to permit microbial growth, if the populations could survive long dormancy periods (∼106 years).
影响因子：
4.8
作者：
Mellon, Michael T.;Arvidson, Raymond E.;Zent, Aaron P.
通讯作者：
Zent, Aaron P.