کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8906757 1634659 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Chlorate brines on Mars: Implications for the occurrence of liquid water and deliquescence
ترجمه فارسی عنوان
کلرات بر روی مریخ آب نمک تاثیری بر وقوع آب مایع و رطوبت دارد
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
چکیده انگلیسی
Oxychlorine salts (chlorates and perchlorates) are globally important components of surface soils on Mars, and could form liquid water in concentrated salt solutions despite prevailing cold and dry conditions. Although perchlorate salts are well-characterized, basic thermodynamic properties of chlorate solutions, such as water activity (aw) and even solubility, are poorly known. To address this knowledge-gap, we measured water activities and solubilities in the Na-Ca-Mg-ClO3 system at 25 °C using the isopiestic method, and fit the data to an aqueous ion-interaction Pitzer model. We find that chlorate solutions have extremely low water activities that could allow liquid water to form on the surface of Mars. Compared to perchlorates, chlorates generally have higher water activities at the same concentration; however, saturated Mg(ClO3)2 solutions, in particular, are extremely concentrated (7.59 mol kg−1) and have aw=0.2 at 25 °C, substantially below saturated Mg(ClO4)2 solutions (aw=0.4). If Mg(ClO3)2 salts are present on Mars' surface, then our results suggest a much greater potential for liquid water formation in soils due to freezing point depression or deliquescence than with perchlorates.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 497, 1 September 2018, Pages 161-168
نویسندگان
, ,