Paleomagnetism. Solar nebula magnetic fields recorded in the Semarkona meteorite.
Magnetic fields are proposed to have played a critical role in some of the most enigmatic processes of planetary formation by mediating the rapid accretion of disk material onto the central star and the formation of the first solids. However, there have been no experimental constraints on the intensity of these fields. Here we show that dusty olivine-bearing chondrules from the Semarkona meteorite were magnetized in a nebular field of 54 ± 21 microteslas. This intensity supports chondrule formation by nebular shocks or planetesimal collisions rather than by electric currents, the x-wind, or other mechanisms near the Sun. This implies that background magnetic fields in the terrestrial planet-forming region were likely 5 to 54 microteslas, which is sufficient to account for measured rates of mass and angular momentum transport in protoplanetary disks.
Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA. rogerfu@mit.edu.
Roger R
RR
Fu
Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.
Benjamin P
BP
Weiss
Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.
Eduardo A
EA
Lima
Department of Earth Sciences, University of Cambridge, Cambridge, UK.
Richard J
RJ
Harrison
Hubble Fellow, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA.
Xue-Ning
XN
Bai
School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA.
Steven J
SJ
Desch
Department of Earth and Planetary Sciences, American Museum of Natural History (AMNH), New York, NY, USA.
Denton S
DS
Ebel
Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.
Clément
C
Suavet
Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.
Huapei
H
Wang
Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA.
David
D
Glenn
Department of Physics, Harvard University, Cambridge, MA, USA.
David
D
Le Sage
Center for Electron Nanoscopy, Technical University of Denmark, Kongens Lyngby, Denmark.
Takeshi
T
Kasama
Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA. Department of Physics, Harvard University, Cambridge, MA, USA.
Ronald L
RL
Walsworth
School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA.
Aaron T
AT
Kuan