Lifetime of the Outer Solar System Nebula from Carbonaceous ChondritesOPEN ACCESS 

Cauê S. Borlina, Benjamin P. Weiss, James F. J. Bryson, Philip J. Armitage

JGR: Planets
First Published: 30 May 2022


“Key Points

  • Paleomagnetic measurements of CO chondrites suggest solar nebula dissipation within 2.7-5.1 Myr after the formation of the solar system
  • The solar nebula went through a two-timescale evolution, consistent with dissipation through photoevaporation and/or magnetized winds
  • We discuss the uncertainties associated with paleomagnetic measurements of bulk chondrites and recommend future directions for the field”

“The evolution and lifetime of protoplanetary disks (PPDs) play a central role in the formation and architecture of planetary systems. Astronomical observations suggest that PPDs evolve in two timescales, accreting onto the star for up to several million years (Myr) followed by gas-dissipation within ≲1 Myr. Because solar nebula magnetic fields are sustained by the gas of the protoplanetary disk, we can use paleomagnetic measurements to infer the lifetime of the solar nebula. Here we use paleomagnetic measurements of meteorites to constrain this lifetime and investigate whether the solar nebula had a two-timescale evolution. We report on paleomagnetic measurements of bulk subsamples of two CO carbonaceous chondrites: Allan Hills A77307 and Dominion Range 08006. If magnetite in these meteorites can acquire a crystallization remanent magnetization that recorded the ambient field during aqueous alteration, our measurements suggest that the local magnetic field strength at the CO parent-body location was <0.9 µT at some time between 2.7-5.1 Myr after the formation of calcium-aluminum-rich inclusions. Coupled with previous paleomagnetic studies, we conclude that the dissipation of the solar nebula in the 3-7 AU region occurred <1.5 Myr after the dissipation of the nebula in the 1-3 AU region, suggesting that protoplanetary disks go through a two-timescale evolution in their lifetime consistent with dissipation by photoevaporation and/or magnetohydrodynamic winds. We also discuss future directions necessary to obtain robust records of solar nebula fields using bulk chondrites, including obtaining ages from meteorites and experimental work to determine how magnetite acquires magnetization during chondrite parent-body alteration.”