Younger Dryas impact model confuses comet facts, defies airburst physics

Abstract

In PNAS, Wittke et al. (1) present evidence that they indicate supports major airbursts and/or impacts at the beginning of the Younger Dryas, as proposed by Firestone et al. (2). One of the major criticisms of the hypothesis has been the lack of any physics-based model for the hypothesized event (3). Wittke et al. (1) attempt to remedy this flaw by including a section entitled “Preliminary Impact Model.” Their model diverges significantly from the original but still provides no physics-based argument and demonstrates a misunderstanding of comets, as well as the physics of airbursts.