The Chicxulub impactor: comet or asteroid?

@inproceedings{Desch2021TheCI,
  title={The Chicxulub impactor: comet or asteroid?},
  author={Steven J. Desch and Alan P. Jackson and Jessica L. Noviello and Ariel D. Anbar},
  year={2021}
}
The discovery by Alvarez et al. (1980) of significant iridium (Ir) in the global K-Pg boundary clay layer at Gubbio, Italy has revolutionized our understanding of the how the geology of Earth is affected by the astronomical goings-on in its neighborhood. Extrapolating from their Ir data, they inferred a 6.6 km-diameter, carbonaceous chondrite-like asteroid as an impactor. Soon after that finding, an Oort cloud comet was suggested as an impactor (Rampino and Stothers, 1984; Davis et al. 1984… 

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