3I/ATLAS: Harvard Astrophysicist Avi Loeb Flags Interstellar Object’s 17th Anomaly Discovered In SPHEREx Data

Did the 3I/ATLAS dupe us Earthlings about its true nature? It would probably take decades until we figured it out. If only we had the mechanism and methodology to reach out to the interstellar interloper on its way to exit the solar system. Discovered on 01 July 2025 by the ATLAS observatory, the third-ever recorded interstellar object since 1I/Oumuamua (2017) and 2I/Borisov (2019), the exocomet entered perihelion on October 27, 2025 and later flew past Earth by 1.8 AU or 270 million kilometers, on December 19, 2025. SETI claimed their 5-hour scan revealed nothing extraordinary. However, Harvard astrophysicist Avi Loeb, who in his handful of recent studies on the exocomet has speculated that the object might be of extraterrestrial technological origin, but somehow we don’t know yet. He has been relentlessly documenting all the anomalies of 3I/ATLAS, and he just spotted another one, the 17th! In a new study done with data compiled from the SPHEREx observatory, researchers found “increased post-perihelion activity” in their paper entitled, “ SPHEREx Re-Observation of Interstellar Object 3I/ATLAS in December 2025: Detection of Increased Post-Perihelion Activity, Refractory Coma Dust, and New Coma Gas Species. ” The study was based on the observations done by NASA’s SPHEREx mission done between 08 and 15 December 2025, ahead of its Earth flyby. The study remarks A new feature is detected at 0.925 um, coincident with a strong emission line of CN gas and consistent with recent reports of optical CN emission at 0.39 um. The H2O-gas feature, barely detected in August, is now 20x stronger for a Qgas, H2O~6x1027 molec/sec, suggesting water is now fully sublimating. New emission detected strongly in bands from 3.2 to 3.6 um denotes the presence of abundant gaseous CH3OH, H2CO, CH4, and C2H6 (hereafter C-H) in the coma. The CO2 emitted flux is only about 33% larger than in August, which verifies that this species was fully active in August pre-perihelion. It adds, The CO emitted flux has increased ~20x, meaning that the CO/CO2 abundance ratio has also increased ~15-fold. Along with the greatly enhanced H2O flux and new C-H species emission, this implies that a new ice reservoir is now active along with the one supporting the CO2 coma. The observation will continue when SPHEREx will study the 3I/ATLAS in April 2026, after its rendezvous with Jupiter’s irregular moon Eupheme in March. Meanwhile, Prof. Loeb made his remark on the study in his latest Medium blog The new images of 3I/ATLAS were taken in the wavelength range of 0.75-5.0 microns between the 8th and 15th of December, 2025. Each image spans 300,000 kilometers on a side. On these large scales, the brightness maps of dust and organics were found to be pear-shaped, with an anti-tail elongation in the direction of the Sun. All six other gas plumes were found to be nearly round. He noted Compared to the pre-perihelion data reported from SPHEREx in August 2025, the continuum spectral signature of water-ice absorption has mostly disappeared, replaced by scattered light plus thermal...

Preview: ~500 words