EXTRAMAG · Paleomagnetism of extraterrestrial materials: a clue to early magnetic fields in the solar system and asteroids differentiation

The study of the remanent magnetization (paleomagnetism) of extraterrestrial materials gives clues as to the history of the primitive solar system and its evolution. Indeed, paleomagnetic studies of meteorites provide a unique window into understanding early solar magnetic fields generated externally from planetesimal bodies (by the young sun during its putative T Tauri phase, or within the protoplanetary nebula), as well as magnetic fields generated within the planetesimals through convection of a molten core (dynamo field).After nearly two decades of relatively dormant activity, the field of extraterrestrial magnetism has recently reactivated, but many questions remain unanswered: Did the Sun pass through a T Tauri phase? How common were differentiated planetesimals with a convective core in the Early solar system? What was the timing of the differentiation of these planetesimals? Did the Moon, or Vesta have a core dynamo? What was the timing of these dynamos?The aim of this project is to participate to the current effort in answering those questions. More precisely we will focus on: 1) primordial fields in the solar nebula