New insight into the Solar System's transition disk phase provided by the unusual meteorite Isheyevo

TL;DR

The Isheyevo meteorite provides the first direct evidence of a transition disk stage in our Solar System, revealing insights into the gas depletion phase during planet formation.

Contribution

This study links meteorite sedimentary features to transition disk conditions, offering new constraints on Solar System evolution.

Findings

Isheyevo formed through gentle sweep-up in a gas-rich environment.

Sedimentary layers indicate formation during a transition disk phase.

Gas densities inferred match those observed in transition protoplanetary disks.

Abstract

Many aspects of planet formation are controlled by the amount of gas remaining in the natal protoplanetary disk (PPDs). Infrared observations show that PPDs undergo a transition stage at several Myr, during which gas densities are reduced. Our Solar System would have experienced such a stage. However, there is currently no data that provides insight into this crucial time in our PPD's evolution. We show that the Isheyevo meteorite contains the first definitive evidence for a transition disk stage in our Solar System. Isheyevo belongs to a class of metal-rich meteorites whose components have been dated at almost 5 Myr after the first solids in the Solar System, and exhibits unique sedimentary layers that imply formation through gentle sedimentation. We show that such layering can occur via gentle sweep-up of material found in the impact plume resulting from the collision of two planetesimals. Such sweep-up requires gas densities consistent with observed transition disks. As such, Isheyevo presents the first evidence of our own transition disk and provides new constraints on the evolution of our solar nebula.