Unless otherwise noted, all illustrations are by Kalliopi Monoyios.
1.1 Photographs of the Greenland crew courtesy of Bill Amaral; used with permission
2.1 Photograph of the “Harvard Computers,” 1913, courtesy of the Harvard College Observatory; used with permission
3.1 Photograph of Beta Pictoris by the European Southern Observatory; rights granted under Creative Commons Attribution 3.0 Unported license (http://creativecommons.org/licenses/by/3.0)
3.2 Photograph from Zion Canyon on Earth by George Alexander Grant for the National Parks Service; image in the public domain. Photograph of Victoria Crater on Mars by NASA/JPL–Caltech/Cornell University; image in the public domain
4.1 Portrait of Seymour Benzer courtesy of the Archives, California Institute of Technology; used with permission
4.2 Photographs of Hindostan limestone tombstones courtesy of the Indiana Geological Society; used with permission
5.1 Portrait of Elso Barghoorn courtesy of the Harvard University Archives, Harvard University Press; used with permission
5.2 Portrait of Anton van Leeuwenhoek by Jan Verkolje (I); image in the public domain. Illustration of van Leeuwenhoek’s microscope courtesy of Michael W. Davidson at Florida State University; used with permission
5.3 Portrait of Galileo Galilei by Domenico Cresti da Passignano; image in the public domain. Etchings by Galileo Galilei, 1638, in the public domain
5.4 Portrait of Preston Cloud courtesy of the Department of Special Collections, Davidson Library, University of California at Santa Barbara; used with permission
6.1 Photograph of Glossopteris fossilized leaf courtesy of the Swedish Museum of Natural History. Photographer: Yvonne Arremo; used with permission
6.2 Alfred Wegener portrait courtesy of the Alfred-Wegener-Institut, Germany; used with permission
6.3 Harry Hess portrait courtesy of the Department of Geosciences, Princeton University, Princeton, N.J.; used with permission
6.4 Photograph of Bruce Heezen and Marie Tharp from the Marie Tharp Estate, courtesy of Fiona Schiano-Yacopina; used with permission
6.5 Map by Bruce Heezen and Marie Tharp; painted by Heinrich Berann; used with permission
6.6 John Tuzo Wilson portrait courtesy of the Ontario Science Centre (www.ontariosciencecentre.ca); used with persission
7.1 Photographs of cliff in Nova Scotia by the author
7.2 Portrait of William Smith by Hugues Fourau; image in the public domain. Photograph of John Phillips, 1907; image in the public domain. Map by William Smith, published 1815; image in the public domain
8.1 Photograph of petrified forest reproduced with the permission of Natural Resources Canada 2011, courtesy of the Geological Survey of Canada (Photographer: Lyn Anglin). Photograph of fossil wood from Kaelin et al., “Comparison of Vitrified and Unvitrified Eocene Woody Tissues by TMAH Thermochemolysis—Implications for the Early Stages of the Formation of Vitrinite,” Geochemical Transactions 7 (2006): 9. Image used under Creative Commons Attribution 2.0 Generic license (http://creativecommons.org/licenses/by/2.0)
9.1 Camp Century photograph from A. Kovacs, “Camp Century Revisited: A Pictorial View—1969,” Cold Regions Research and Engineering Laboratory Special Report 150 (July 1970): 44, 49; image in the public domain
9.2 Photograph of Louis Agassiz circa 1860; image in the public domain
9.3 Etching of James Croll by unknown artist, published in Popular Science Monthly 51 (August 1897): 445; image in the public domain
9.4 Portrait of Milutin Milankovitch by Paja Jovanovic´ (1859–1957); image in the public domain
9.5 Photograph of Dorothy Garrod courtesy of Mrs. Kennedy Shaw and her daughter, Mrs. Caroline Burkitt. Photograph in possession of Pamela Jane Smith; used with permission