火星凤凰号着陆点存在碳酸钙的证据。

Evidence for calcium carbonate at the Mars Phoenix landing site.

作者信息

Boynton W V, Ming D W, Kounaves S P, Young S M M, Arvidson R E, Hecht M H, Hoffman J, Niles P B, Hamara D K, Quinn R C, Smith P H, Sutter B, Catling D C, Morris R V

机构信息

Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA.

出版信息

Science. 2009 Jul 3;325(5936):61-4. doi: 10.1126/science.1172768.

DOI:10.1126/science.1172768

PMID:19574384

Abstract

Carbonates are generally products of aqueous processes and may hold important clues about the history of liquid water on the surface of Mars. Calcium carbonate (approximately 3 to 5 weight percent) has been identified in the soils around the Phoenix landing site by scanning calorimetry showing an endothermic transition beginning around 725 degrees C accompanied by evolution of carbon dioxide and by the ability of the soil to buffer pH against acid addition. Based on empirical kinetics, the amount of calcium carbonate is most consistent with formation in the past by the interaction of atmospheric carbon dioxide with liquid water films on particle surfaces.

摘要

碳酸盐通常是水相过程的产物，可能蕴含着有关火星表面液态水历史的重要线索。通过扫描量热法已在凤凰号着陆点周围的土壤中识别出碳酸钙（约3至5重量百分比），该方法显示在约725摄氏度开始出现吸热转变，伴有二氧化碳释放，且土壤具有缓冲添加酸的pH值的能力。基于经验动力学，碳酸钙的量与过去大气二氧化碳与颗粒表面液态水膜相互作用形成的情况最为相符。