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Measuring the level of interstellar inheritance in the solar protoplanetary disk
Author(s) -
Alexander Conel M. O'D.,
Nittler Larry R.,
Davidson Jemma,
Ciesla Fred J.
Publication year - 2017
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/maps.12891
Subject(s) - protoplanetary disk , interplanetary dust cloud , physics , formation and evolution of the solar system , astrobiology , astrophysics , chondrite , cosmic dust , solar system , planetesimal , comet , accretion (finance) , astronomy , carbonaceous chondrite , planet , meteorite
The timing and extent to which the initial interstellar material was thermally processed provide fundamental constraints for models of the formation and early evolution of the solar protoplanetary disk. We argue that the nonsolar (solar Δ 17 O ≈ −29‰) and near‐terrestrial (Δ 17 O ≈ 0‰) O‐isotopic compositions of the Earth and most extraterrestrial materials (Moon, Mars, asteroids, and comet dust) were established very early by heating of regions of the disk that were modestly enriched (dust/gas ≥ 5–10 times solar) in primordial silicates (Δ 17 O ≈ −29‰) and water‐dominated ice (Δ 17 O ≈ 24‰) relative to the gas. Such modest enrichments could be achieved by grain growth and settling of dust to the midplane in regions where the levels of turbulence were modest. The episodic heating of the disk associated with FU Orionis outbursts were the likely causes of this early thermal processing of dust. We also estimate that at the time of accretion the CI chondrite and interplanetary dust particle parent bodies were composed of ~5–10% of pristine interstellar material. The matrices of all chondrites included roughly similar interstellar fractions. Whether this interstellar material avoided the thermal processing experienced by most dust during FU Orionis outbursts or was accreted by the disk after the outbursts ceased to be important remains to be established.