Understanding Earth
JOHN GROTZINGER is a Field Geologist interested in the evolution of Earth's surficial environments and biosphere. He is the Fletcher Jones Professor of Geology at Caltech University College, USA. In addition, he served as a member of the Geology Group on the Mars Exploration Rover mission in 2004 when it was discovered that water was once abundant on the ancient surface of Mars. He is a member of the American Academy of Arts and Sciences and the US National Academy of Sciences.  THOMAS H. JORDAN is a Geophysicist interested in the composition, dynamics, and evolution of the solid Earth. He is the W. M. Keck Professor of Geological Sciences at the University of Southern California, USA, and Director of the Southern California Earthquake Centre, USA. He is a member of the American Academy of Arts and Sciences, the US National Academy of Sciences, and the American Philosophical Society.   FRANK PRESS was formerly on the faculties of Columbia University, Caltech, and MIT, USA. He served as President of the US National Academy of Sciences. He has advised four US Presidents on scientific issues. Three times, US News& World Report surveys named him the country's most influential scientist.   RAYMOND SIEVER was an internationally known expert in sedimentary petrology, geochemistry, and the evolution of oceans and the atmosphere. He was a long-time member of Harvard University's Department of Earth and Planetary Sciences, and he chaired the Geology Department for eight years. Dr Siever was a fellow of the Geological Society of America and the American Academy of Arts and Sciences, and has been honoured with distinguished awards from the Society of Sedimentary Geology, the Geochemical Society, and the American Association of Petroleum Geologists.--This text refers to an alternatePaperbackedition.