February 6, 2008 > Book Review
The Geology of Mars: Evidence from Earth-Based Analogs
By Robert A. Garfinkle
"The Geology of Mars: Evidence from Earth-Based Analogs," edited by Mary Chapman. Cambridge University Press, $135.00, ISBN 987-0-521-83292-2, 460 pages.
In the past few years, we have sent spacecraft to the planet Mars and received valuable data returned from them. Editor Mary Chapman has put together a package of 17 articles that reveal what we have learned from the data sent back by the Mars Global Surveyor, Mars Odyssey, Mars Express, and the two Mars Exploration Rovers. Planetary geologists have now used this data to compare Martian features with similar features here in order to try to understand the formation process of the topography of the red planet. These scientists have discovered many parallels as well as differences in how these two planets have evolved since their formation billions of years ago.
The first article gives an overview of the geology of Mars and discusses the major dynamic forces that have shaped the surfaces, crusts, and lithospheres of both planets. Both the internal processes (volcanism) and the external forces (impact cratering) that have created the topography that we see today are covered.
Another article shows us where and how impact structures are analogous on both planets. On Earth, the constant forces of erosion have obliterated most of the impacts that Earth received during the era of about 3.8 billion years ago, known as the late heavy bombardment period. On Mars, approximately 60 percent of the impact cratering from that era remains and gives us a good glimpse into the early record of the Solar System.
The third article is a fascinating look at terrestrial volcanoes and how they compare with the giant calderas of the Tharsis region on Mars. There are a lot of similarities between these large Martian calderas and the calderas on the Hawaiian Islands.
Other articles cover volcanic features in New Mexico with similar ones on Mars. We read about flood lavas found on both planets and compare rootless volcanic cones on Iceland with analogous features on Mars. The Earth has many playa regions (dry lakes) that today are large flat deserts. We think that similar features exist on Mars as well, and if Mars does have playas, then that would have significant implications for the planet's hydro climatic history. If Mars had water, did it also have life? This is probably a primary question that still needs to be conclusively answered.
"The Geology of Mars: Evidence from Earth-Based Analogs" is rather technical in its presentation and is geared for the more experienced Martian observer or planetary geologist. The book is packed with numerous spacecraft images of Martian features being discussed and terrestrial features. At the end of each article are extensive lists of the reference articles called out in the text. I enjoyed reading this book and learning about the latest theories about the evolution of Mars. The article authors are very knowledgeable in their areas of expertise. I highly recommend this book to those with the scientific background or good understanding of geology in order to get the most out of this book. Casual observers of the Red Planet will learn from it as well.