History of the Solar Nebula from Meteorite Paleomagnetism

TL;DR

This paper reviews recent findings on the magnetic history of the solar nebula through meteorite paleomagnetism, highlighting the role of magnetic fields in planetary formation and nebular evolution over time.

Contribution

It synthesizes meteorite measurements, theory, and astronomical observations to trace magnetic field strengths and their implications for the early solar system's evolution.

Findings

Magnetic fields of ~0.54 G at 1-3 AU during early solar system phases.

Magnetic fields >0.06 G at 3-7 AU until over 1 million years after formation.

Nebular magnetic fields declined to below 0.006 G by nearly 4 million years, indicating gas dispersal.

Abstract

We review recent advances in our understanding of magnetism in the solar nebular and protoplanetary disks (PPDs). We discuss the implications of theory, meteorite measurements, and astronomical observations for planetary formation and nebular evolution. Paleomagnetic measurements indicate the presence of fields of 0.54$\pm$0.21 G at $\sim$1 to 3 astronomical units (AU) from the Sun and $\gtrsim$0.06 G at 3 to 7 AU until >1.22 and >2.51 million years (Ma) after solar system formation, respectively. These intensities are consistent with those predicted to enable typical astronomically-observed protostellar accretion rates of $\sim$10$^{-8}$ M$_\odot$ yr$^{-1}$, suggesting that magnetism played a central role in mass and angular momentum transport in PPDs. Paleomagnetic studies also indicate fields <0.006 G and <0.003 G in the inner and outer solar system by 3.94 and 4.89 Ma, respectively, consistent with the nebular gas having dispersed by this time. This is similar to the observed lifetimes of extrasolar protoplanetary disks.