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Paleomagnetism. Solar nebula magnetic fields recorded in the Semarkona meteorite
Roger R Fu1, Benjamin P Weiss2, Eduardo A Lima2
1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA. rogerfu@mit.edu.
Science (New York, N.Y.)
|November 15, 2014
Summary
Early planetary formation may have involved strong magnetic fields. Analysis of meteorites reveals nebular magnetic fields of 54 ± 21 microteslas, supporting key theories of planet formation.
Area of Science:
- Planetary Science
- Astrophysics
- Geophysics
Background:
- Magnetic fields are hypothesized to be crucial for planetary formation.
- They may regulate material accretion and the creation of early solids.
- Previous research lacked experimental data on the intensity of these ancient magnetic fields.
Purpose of the Study:
- To experimentally determine the intensity of magnetic fields during the early stages of planetary formation.
- To test hypotheses regarding the mechanisms of chondrule formation and protoplanetary disk dynamics.
Main Methods:
- Analysis of dusty olivine-bearing chondrules from the Semarkona meteorite.
- Paleomagnetic analysis to determine the intensity of the ancient magnetic field recorded in the chondrules.
Main Results:
- Chondrules from the Semarkona meteorite were magnetized in a nebular field of 54 ± 21 microteslas.
- This field strength supports formation mechanisms like nebular shocks or planetesimal collisions.
- Estimated background magnetic fields in the terrestrial planet-forming region were between 5 and 54 microteslas.
Conclusions:
- The measured magnetic field intensity is sufficient to explain mass and angular momentum transport in protoplanetary disks.
- These findings provide crucial experimental constraints on the role of magnetic fields in planet formation.
- The results favor certain chondrule formation models over others, refining our understanding of the early solar system.
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