Book Review: Cold Aqueous Planetary Geochemistry with FREZCHEM – From Modeling to the Search for Life at the Limits

Abstract

Through the last decades the importance of understanding the chemistry of cold aqueous environments, both on the Earth and other planetary bodies, has become increasingly clear. The FREZCHEM program, which constitutes the core of the book written by Giles Marion and Jeffrey Kargel (as clearly stated in the title), is a powerful theoretical tool to contribute to this task. Since 1994 – date of publication of the first version of FREZCHEM – almost ten versions and adaptations progressively have increased its power, versatility and capability of dealing with chemically complex scenarios. Now, the program is mature enough to justify a book. Indeed, this book is a guide for the introduction to, and the use of, FREZCHEM (in fact, the appendix A is literally a “program guide”), but it is more. For example, the explanation of the theoretical basis for the program building constitutes an excellent review of the principles of the thermodynamics of aqueous solutions. An additional merit is a clear specification of the program limits and conditions of applicability. Therefore, the book will be of great interest for researchers on the chemistry of cold aqueous solutions, and it is an excellent guide to the use of FREZCHEM. But the book has other prominent merits. For example, chapter 5 includes a synthesis of results obtained by previous works using FREZCHEM, which deal with a variety of topics. For Earth, they include analysis of the chemistry of aqueous saline environments (which can be standing water bodies, but also soils or sea ice), the ocean chemistry during snowball or hothouse episodes, or the evolution of freezing seawater. FREZCHEM has also been applied to study the composition and geochemical evolution of ancient waters on Mars, and to the composition of both the icy shell and internal ocean of Europa. As recognized by the authors, the results for Mars Orig Life Evol Biosph (2008) 38:371–372 DOI 10.1007/s11084-008-9142-5