The Anti-Tail of 3I/ATLAS Extends Beyond The Distance To The Moon Spanning Half a Million Kilometers

Our difficulty in assessing how anomalous 3I/ATLAS truly is stems from a simple statistical problem. We do not yet have a meaningful census of interstellar objects. Current survey systems such as Pan-STARRS, ATLAS, and the soon-to-be-fully-operational Rubin Observatory can only detect objects larger than roughly 100 meters across within distances comparable to the Earth–Sun separation. Objects smaller than that, or moving significantly faster than typical asteroids and comets, would pass through the inner solar system unnoticed. In other words, we are sampling only the largest and slowest members of a population we barely understand.

This uncertainty feeds directly into the Loeb Classification Scale, which attempts to rank interstellar objects based on how strongly their properties deviate from natural expectations. To apply that scale responsibly, we need probability distributions—how common certain behaviors are, how often outliers appear, and where 3I/ATLAS truly falls. Right now, our dataset is too small to offer comfort. Each new interstellar visitor carries disproportionate weight, much like early data points in any forensic investigation.