Magnetic field strengths as a function of distance from the Sun for several meteorite samples
Compilation of magnetic field strengths estimated from studies of meteorites of different ages. The new result of this work is the CV point (orange), which suggests a spatial or temporal variation in field strength. Such variations are indicative of complex structure or dynamics in the protoplanetary disk. Orbital radius is an estimate based on the isotopic characteristics of the meteorites. Credit: Fu et al., 2021, Figure 6
Source: AGU Advances

The early solar nebula was probably subject to strong magnetic fields, which influenced its dynamics and thus the rate at which the Sun and planets grew. Fortunately, some meteorites were forming during this epoch, and thus provide the potential to characterize these ancient nebular fields. Fu et al. [2021] make careful measurements of one particular meteorite and conclude that the fields recorded are an order of magnitude larger than fields recorded by other meteorites of similar ages. This result suggests that the nebula experienced either strong temporal variations in field strength, or strong spatial variations (for instance, because of the presence of gaps cleared by growing planets). As highlighted by Nichols [2021] in a companion Viewpoint, an important next step is to understand in more detail the chemical process(es) by which magnetization was acquired; so too is removing the lingering possibility that this field was due to an internal dynamo, rather than an external nebular field.

Citation: Fu, R., Volk, M., Bilardello, D., Libourel, G., Lesur, G., & Ben Dor, O. [2021]. The fine-scale magnetic history of the Allende meteorite: Implications for the structure of the solar nebula. AGU Advances, 2, e2021AV000486.

—Francis Nimmo, Editor, AGU Advances

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