NEW INSIGHT INTO THE SOLAR SYSTEM'S TRANSITION DISK PHASE PROVIDED BY THE METAL-RICH CARBONACEOUS CHONDRITE ISHEYEVO

作者：Morris Melissa A^*; Garvie Laurence A J; Knauth L Paul

来源：Astrophysical Journal Letters, 2015, 801(2): L22.

DOI：10.1088/2041-8205/801/2/L22

• meteorites, meteors, meteoroids
• planet-disk interactions
• planets and satellites: formation
• protoplanetary disks

Many aspects of planet formation are controlled by the amount of gas remaining in the natal protoplanetary disks (PPDs). Infrared observations show that PPDs undergo a transition stage at several megayears, 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 formation of Ca, Al-rich inclusions, and exhibits unique sedimentary layers that imply formation through gentle sedimentation. We show that such layering can occur via the 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 (10(-12)-10(-11) g cm(-3)). As such, Isheyevo presents the first evidence of our own transition disk and provides new constraints on the evolution of our solar nebula.

• 出版日期2015-3-10