'Oumuamua (1I/2017 U1).
disputedscientific_anomalyScientific Instrumentation & Sensor Data
First confirmed interstellar object (2017); showed non-gravitational acceleration. Loeb proposed an alien light-sail; consensus favors natural ice/fragment origin.
Discovered Oct 2017 via Pan-STARRS, 'Oumuamua was highly elongated and accelerated slightly without visible cometary outgassing. Loeb & Bialy (2018) argued solar radiation pressure on a thin artificial light sail could explain this. The scientific mainstream rejects the artifact reading, favoring exotic ices (H2/N2), comet fragments, or tidal-disruption debris. The 2020 SO case, an 'Oumuamua-like object that proved to be a 1966 rocket booster, is cited as a caution. [REAL DATA] Detector #1 run on the actual JPL Small-Body DataBase (2026): of ~1.4M catalogued asteroids only 22 carry a radial non-grav term (A1); 'Oumuamua is the extreme standout at |A1|=2.8e-7 AU/day^2 -- 25x the next object, ~3457x the population median, class HYA (interstellar), with no detected coma. The residual-mining discriminant, run blind on real data, isolates exactly this object. NO artificiality claimed; it is the case where a natural coupling is hardest to close.