Calibration of CNEOS Fireball Velocities and the Robustness of Nominally Hyperbolic EventsOPEN ACCESS
Volkan Duran, Abraham Loeb
“The NASA/JPL CNEOS Fireball Data catalogue provides a near-global record of bright atmospheric entries but does not report per-event velocity covariance. We calibrate its kinematic accuracy using 19 events with independent reference trajectories and use optical, satellite, radar, and infrasound catalogues as source-specific controls. For nine modern high-quality comparisons, the CNEOS-minus-reference speed residual has mean -1.00 km s-¹ and standard deviation .86 km s-¹; variance decomposition assigns 0.77 km s-¹ to the CNEOS component. The radiant residuals have a 0.74 degree per-axis core plus one 16.3 degree outlier, so the extreme tail remains poorly determined. Seven of 354 complete CNEOS states are nominally hyperbolic without correction. A +0.9935 km s-¹ atmospheric-stage shift produces five additional crossings, but these are treated only as sensitivity cases. Polar-IM (2026 April 1) is the strongest post-2018 CNEOS anomaly, whereas independent GLM-LI stereo solutions yield 57.3 ± 2.0 and 56.7 ± 3.0 km s-¹, close to their direction-specific parabolic thresholds. We conclude that CNEOS can identify priority candidates, but secure interstellar classification requires an independent, uncertainty-bearing three-dimensional trajectory for the same event.”
