Habitability of the Phoenix landing site
Habitability of the Phoenix landing site
复制标题
凤凰城着陆点的宜居性
DOI：
10.1029/2009je003421
复制
发表时间：
2010
影响因子：
--
通讯作者：
S. M. Young
中科院分区：
文献类型：
--
作者：
C. Stoker;A. Zent;D. Catling;S. Douglas;J. Marshall;D. Archer;B. Clark;S. Kounaves;M. Lemmon;R. Quinn;N. Renno;Peter H. Smith;S. M. Young
[1] 凤凰城任务的主要目标是寻找宜居区。任务结果用于评估凤凰号着陆地点的宜居性。宜居性概率 (HI) 定义为存在液态水 (Plw)、能量 (Pe)、营养物 (Pch) 和良性环境 (Pb) 的概率的乘积。存在液态水（过去或现在）的观测证据包括多边形边界处的干净冰、土壤颗粒的化学蚀刻和碳酸盐矿物。地表和近地表下冰的存在，以及支持融化的热力学条件，表明液态水在理论上是可能的。目前，未冻结的水只能在吸附膜或盐水中形成，但由于轨道参数的变化，更温和的条件会定期出现。当半透明的土壤颗粒提供紫外线辐射屏蔽以及高氯酸盐和还原铁的氧化还原对的化学能时，可以从阳光中获得驱动新陈代谢的能量。包括 C、H、N、O、P 和 S 化合物的营养源由已知的大气源或全球灰尘提供。环境条件在陆地微生物的生长耐受范围内。目前，表层土壤温度达到 260 K，并且周期性地更高，pH 值为 7.8，缓冲良好，水分活度足够高，可以在有足够水时允许生长。计算着陆器访问地点的 HI 得出 Phoenix，0.47；子午线，0.23；古谢夫，0.22；探路者，0.05；维京人 1, 0.01;维京人 2，0.07。菲尼克斯遗址的 HI 是所有探索过的遗址中最大的，但不同的测量结果限制了比较的可信度。
[1] The Phoenix mission's key objective was to search for a habitable zone. Mission results are used to evaluate habitability where Phoenix landed. A habitability probability (HI) is defined as the product of probabilities for the presence of liquid water (Plw), energy (Pe), nutrients (Pch), and a benign environment (Pb). Observational evidence for the presence of liquid water (past or present) includes clean ice at a polygon boundary, chemical etching of soil grains, and carbonate minerals. The presence of surface and near subsurface ice, along with thermodynamic conditions that support melting, suggest that liquid water is theoretically possible. Presently, unfrozen water can form only in adsorbed films or saline brines but more clement conditions recur periodically due to variations in orbital parameters. Energy to drive metabolism is available from sunlight, when semitransparent soil grains provide shielding from UV radiation and chemical energy from the redox couple of perchlorate and reduced iron. Nutrient sources including C, H, N, O, P, and S compounds are supplied by known atmospheric sources or global dust. Environmental conditions are within growth tolerance for terrestrial microbes. Surface soil temperatures currently reach 260 K and are periodically much higher, the pH is 7.8 and is well buffered, and the water activity is high enough to allow growth when sufficient water is available. Computation of HI for the sites visited by landers yields Phoenix, 0.47; Meridiani, 0.23; Gusev, 0.22; Pathfinder, 0.05; Viking 1, 0.01; Viking 2, 0.07. HI for the Phoenix site is the largest of any site explored, but dissimilar measurements limit the comparisons' confidence.
影响因子：
4.8
作者：
Hecht, M. H.;Marshall, J.;Woida, P. M.
通讯作者：
Woida, P. M.
影响因子：
4.8
作者：
Mellon, Michael T.;Arvidson, Raymond E.;Zent, Aaron P.
通讯作者：
Zent, Aaron P.