Space Sci Rev DOI 10.1007/s11214-010-9644-0 The Magnetic Field of Planet Earth G. Hulot · C.C. Finlay · C.G. Constable · N. Olsen · M. Mandea Received: 22 October 2009 / Accepted: 26 February 2010 © The Author(s) 2010. This article is published with open access at Springerlink.com Abstract The magnetic field of the Earth is by far the best documented magnetic field of all known planets. Considerable progress has been made in our understanding of its charac- teristics and properties, thanks to the convergence of many different approaches and to the remarkable fact that surface rocks have quietly recorded much of its history. The usefulness of magnetic field charts for navigation and the dedication of a few individuals have also led to the patient construction of some of the longest series of quantitative observations in the history of science. More recently even more systematic observations have been made pos- sible from space, leading to the possibility of observing the Earth’s magnetic field in much more details than was previously possible. The progressive increase in computer power was also crucial, leading to advanced ways of handling and analyzing this considerable corpus G. Hulot () Equipe de Géomagnétisme, Institut de Physique du Globe de Paris (Institut de recherche associé au CNRS et à l’Université Paris 7), 4, Place Jussieu, 75252, Paris, cedex 05, France e-mail:
[email protected] C.C. Finlay ETH Zürich, Institut für Geophysik, Sonneggstrasse 5, 8092 Zürich, Switzerland C.G. Constable Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0225, USA N.