Firestone, Kennett, West, and colleagues argued in a 2007 paper in Proceedings of the National Academy of Sciences that Earth experienced an extraterrestrial impact around 12,900 years ago at the onset of the Younger Dryas stadial.
Notes on verification
Publication details, authorship, and core argument are verified directly against the PNAS paper and PMC record. The hypothesis itself remains scientifically contested, but the claim only asserts that the paper made this argument, which is well corroborated. [tier=silver indep_score=1.0 clusters=2 claim_tier=notable]
Sources
- An independent evaluation of the Younger Dryas - jstor (seed:history_and_archaeology)
- https://www.pnas.org/doi/10.1073/pnas.0706977104 (corroboration)
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994902/ (corroboration)