Peak-Brightness Localization of the CNEOS 2014-01-08 (IM1) Fireball

Abstract

In a recent preprint, Fernando et al. (2024) used public data from infrasound stations to constrain the localization of the fireball of the CNEOS 2014-01-08 (IM1) bolide. The analysis inferred a 90-percent-confidence ellipse with semi-minor and semi-major axes of 186 and 388 km, respectively. This large error ellipse includes the much better localization box derived by sensors aboard U.S. Government satellites which detected the fireball light. At the fireball's peak brightness, the CNEOS localization box documented by NASA/JPL measures 11.112km on a side and is centered on a latitude of 1.3S and a longitude of 147.6E. Here, we point out that the recent expedition to retrieve materials from IM1's site (Loeb et al. 2024a,b,c) surveyed a region of tens of km around the CNEOS box center, and was not dictated by the data studied by Fernando et al. (2024) because of its larger uncertainties.