Fireball calibration narrows what an interstellar claim needs

Volkan Duran and Abraham Loeb compared NASA/JPL's CNEOS fireball records with 19 events that also have trajectories from optical, satellite, radar, or infrasound sources. For nine modern high-quality comparisons, they report that CNEOS speeds averaged 1.00 kilometer per second below the references, with a standard deviation of 0.86 kilometer per second; their variance model assigns 0.77 kilometer per second to the CNEOS component. Directional residuals were usually small but included one 16.3-degree outlier, leaving the extreme error tail poorly constrained.

Seven of 354 complete CNEOS state vectors are nominally hyperbolic before correction, meaning their listed speeds and directions would place them above the local solar-system escape threshold. The paper identifies an April 1 event called Polar-IM as the strongest post-2018 catalog anomaly, while two independent stereo solutions remain close to their direction-specific thresholds rather than securely beyond them. The authors therefore treat CNEOS as a candidate-finding tool and require an independent, uncertainty-bearing three-dimensional trajectory for a robust interstellar classification.

Why it matters

Claims about interstellar meteors can turn small velocity errors into enormous origin stories. A published calibration shows which measurements are useful, which uncertainties dominate, and what independent evidence is still required.

What the source establishes

Verified unreviewed preprint and reported calibration results. Nominally hyperbolic catalog entries are candidates, not confirmed interstellar objects; Polar-IM is not identified as artificial.