We have used scaling estimates and thermal evolution models to demonstrate that dynamos could have been active on small solar system bodies (such as planetesimals and asteroids) in the early solar system. These dynamos likely explain the existence of strong, stable magnetic fields in certain ancient meteorites. Relevant papers include:

• Scheinberg, A., Fu, R.R., Elkins-Tanton, E., Weiss, B.P. & Stanley, S., “Magnetic fields on asteroids and planetesimals”, in Planetesimals: Early Differentiation and Consequences for Planets, ed. Elkins-Tanton, L.T. & Weiss, B.P., Cambridge University Press, in press.

• Weiss, B.P., Rochette, P., Stanley, S., Paleomagnetic Records of Meteorites and Early Planetesimal Differentiation, Space Sci. Rev. 152, 341-490 (2010).

•  Weiss, B.P., Berdahl, J.S., Elkins-Tanton, L.T., Stanley, S., Lima, E.A., Carporzen, L., Magnetism on the Angrite Parent Body and the Early Differentiation of Planetesimals, Science, 322, 713-716 (2008).