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<\/picture><\/div>\n<\/div>\nA false-color image of 3I\/ATLAS, taken on November 22, 2025. The sunward direction is towards the lower left. (Credit:\u00a0Alfons Diepvens, Belgium<\/a>)<\/h5>\nAvi Loeb<\/p>\n
The time is ripe to summarize the anomalies of the interstellar object\u00a03I\/ATLAS<\/a>\u00a0in ascending order of likelihood. Here is the list, split into three categories, along with the probability,\u00a0P,<\/strong>\u00a0associated with each item:<\/p>\nI.<\/em><\/strong>\u00a0Major anomalies with no simple explanation:<\/em><\/strong><\/p>\n1.\u00a0P=0.00004:<\/strong>\u00a0The forecasted perijove distance of 3I\/ATLAS during its encounter with Jupiter on March 16, 2026 is 53.445 (+\/- 0.06) million kilometers, identical to Jupiter\u2019s Hill radius, 53.502 million kilometers (see\u00a0here<\/a>). This match was enabled by the non-gravitational acceleration that 3I\/ATLAS displayed near perihelion. The rare coincidence might mean that 3I\/ATLAS intends to release technological devices as\u00a0artificial satellites of Jupiter<\/mark>, potentially at Jupiter\u2019s Lagrange points L1 and L2 at the Hill radius \u2014 where orbital corrections and fuel requirements are minimal<\/p>\n2.\u00a0P=0.00005<\/strong>: The arrival time of 3I\/ATLAS was fine-tuned to bring it within tens of millions of kilometers from Mars, Venus and Jupiter and be unobservable from Earth at perihelion (see\u00a0here<\/a>).<\/p>\n3.\u00a0P<0.001:<\/strong>\u00a0The nucleus of 3I\/ATLAS is roughly a million times more massive than\u00a01I\/`Oumuamua<\/a>\u00a0and a thousand times more massive than\u00a02I\/Borisov<\/a>, while moving faster than both (see\u00a0here<\/a>\u00a0and\u00a0here<\/a>). There is not enough rocky material in interstellar space to deliver a rock of this mass once per decade to the inner solar system (see\u00a0here<\/a>). This suggests that 3I\/ATLAS may have targeted the inner solar system rather than was drawn at random from the reservoir of interstellar rocks.<\/p>\n4.\u00a0P<0.001:<\/strong>\u00a0During July and August as well as through November of 2025, 3I\/ATLAS displayed a sunward jet (anti-tail) that is not an optical illusion from geometric perspective, unlike thousands of known comets (see\u00a0here<\/a>). The HiRISE image taken at closest approach of 3I\/ATLAS to Mars, confirmed a glowing extension ahead of 3I\/ATLAS along the direction of motion (see\u00a0here<\/a>). For a technological object, a beam of light or particles might be used to mitigate the risk from micrometeorites or rocks that could impact its surface at a relative speed of order 60 kilometers per second and release a thousand times more energy per unit mass than explosives.<\/p>\n5.\u00a0P<0.001:<\/strong>\u00a0The gas plume surrounding 3I\/ATLAS contains much more nickel than iron as found in industrially-produced nickel alloys, and a nickel to cyanide ratio that is orders of magnitude larger than for thousands of known comets, including 2I\/Borisov (see\u00a0here<\/a>). This might indicate an artificial origin of these unusual abundances.<\/p>\n6.\u00a0P=0.002:\u00a0<\/strong>The retrograde trajectory of 3I\/ATLAS is aligned to within 5 degrees with the ecliptic plane of the planets around the Sun (see\u00a0here<\/a>). This suggests that the trajectory may have been designed.<\/p>\nII.<\/em><\/strong>\u00a0Medium anomalies, which could be a statistical fluke:<\/em><\/strong><\/p>\n1.\u00a0P=0.006:<\/strong>\u00a03I\/ATLAS arrived from a direction coincident with the radio \u201cWow! Signal\u201d to within 9 degrees (see\u00a0here<\/a>).<\/p>\n2.\u00a0P<0.01:<\/strong>\u00a03I\/ATLAS shows extreme negative polarization, unprecedented for all known comets, including 2I\/Borisov (see\u00a0here<\/a>). This unusual polarization may be related to its unusual anti-tail.<\/p>\nIII.<\/em><\/strong>\u00a0Minor anomalies, which could potentially be explained by a unique origin:<\/em><\/strong><\/p>\n1.\u00a0P<0.1:<\/strong>\u00a0The gas plume surrounding 3I\/ATLAS contains only 4% water by mass, a dominant constituent of familiar solar-system comets (see\u00a0here<\/a>). The plume might have resulted from the sunlight releasing the ices and dust that accumulated on the surface of a technological object during its journey through the cold interstellar medium.<\/p>\n2.\u00a0P<0.1:<\/strong>\u00a0Near perihelion, 3I\/ATLAS brightened faster than any known comet and was bluer than the Sun (see\u00a0here<\/a>). This might be a signature that its engine turned on.<\/p>\n3.\u00a0P<0.1:<\/strong>\u00a03I\/ATLAS exhibits sunward and anti-solar jets which require an unreasonably large surface area for a natural comet in order to absorb enough sunlight needed to sublimate enough ice to feed the mass flux of these jets (as calculated\u00a0here<\/a>). The jets might originate from technological thrusters.<\/p>\n4.\u00a0P<0.1:<\/strong>\u00a0The tightly-collimated jets from 3I\/ATLAS maintain orientation across a million kilometers in multiple directions relative to the Sun despite its measured rotation. The jets might originate from technological thrusters.<\/p>\n5.\u00a0P<0.1:<\/strong>\u00a0Near perihelion 3I\/ATLAS exhibits non-gravitational acceleration which requires massive evaporation for a natural comet (as calculated\u00a0here<\/a>), whereas preliminary images indicate that the object maintained its integrity and did not break up (as discussed\u00a0here<\/a>). Instead, the acceleration might have been produced by an engine.<\/p>\n***<\/p>\n
The probability for the combined occurrence of multiple independent anomalies is the product of their individual probabilities.<\/mark>\u00a0From the above list, it is apparent that 3I\/ATLAS is an extremely rare and mysterious object, especially if it happens to be a natural comet as argued by NASA officials at the press conference on November 19, 2025 (accessible\u00a0here<\/a>).<\/p>\nRegarding the updated ranking of 3I\/ATLAS on the Loeb Scale (as defined\u00a0here<\/a>\u00a0and\u00a0here<\/a>), I would prefer to wait for the flood of new data in the coming weeks before revising my previous value.<\/p>\nIn an interview on\u00a0NewsNation<\/em>\u00a0last night (accessible\u00a0here<\/a>), the brilliant Natasha Zouves asked me what data am I most looking for in the coming weeks. I explained that\u00a0a spectroscopic measurement of the speed and composition of the jets<\/mark>\u00a0of 3I\/ATLAS would reveal whether they stem from the sublimation of pockets of ice on the surface of a rock or from technological thrusters.<\/p>\n
I.<\/em><\/strong>\u00a0Major anomalies with no simple explanation:<\/em><\/strong><\/p>\n 1.\u00a0P=0.00004:<\/strong>\u00a0The forecasted perijove distance of 3I\/ATLAS during its encounter with Jupiter on March 16, 2026 is 53.445 (+\/- 0.06) million kilometers, identical to Jupiter\u2019s Hill radius, 53.502 million kilometers (see\u00a0here<\/a>). This match was enabled by the non-gravitational acceleration that 3I\/ATLAS displayed near perihelion. The rare coincidence might mean that 3I\/ATLAS intends to release technological devices as\u00a0artificial satellites of Jupiter<\/mark>, potentially at Jupiter\u2019s Lagrange points L1 and L2 at the Hill radius \u2014 where orbital corrections and fuel requirements are minimal<\/p>\n 2.\u00a0P=0.00005<\/strong>: The arrival time of 3I\/ATLAS was fine-tuned to bring it within tens of millions of kilometers from Mars, Venus and Jupiter and be unobservable from Earth at perihelion (see\u00a0here<\/a>).<\/p>\n 3.\u00a0P<0.001:<\/strong>\u00a0The nucleus of 3I\/ATLAS is roughly a million times more massive than\u00a01I\/`Oumuamua<\/a>\u00a0and a thousand times more massive than\u00a02I\/Borisov<\/a>, while moving faster than both (see\u00a0here<\/a>\u00a0and\u00a0here<\/a>). There is not enough rocky material in interstellar space to deliver a rock of this mass once per decade to the inner solar system (see\u00a0here<\/a>). This suggests that 3I\/ATLAS may have targeted the inner solar system rather than was drawn at random from the reservoir of interstellar rocks.<\/p>\n 4.\u00a0P<0.001:<\/strong>\u00a0During July and August as well as through November of 2025, 3I\/ATLAS displayed a sunward jet (anti-tail) that is not an optical illusion from geometric perspective, unlike thousands of known comets (see\u00a0here<\/a>). The HiRISE image taken at closest approach of 3I\/ATLAS to Mars, confirmed a glowing extension ahead of 3I\/ATLAS along the direction of motion (see\u00a0here<\/a>). For a technological object, a beam of light or particles might be used to mitigate the risk from micrometeorites or rocks that could impact its surface at a relative speed of order 60 kilometers per second and release a thousand times more energy per unit mass than explosives.<\/p>\n 5.\u00a0P<0.001:<\/strong>\u00a0The gas plume surrounding 3I\/ATLAS contains much more nickel than iron as found in industrially-produced nickel alloys, and a nickel to cyanide ratio that is orders of magnitude larger than for thousands of known comets, including 2I\/Borisov (see\u00a0here<\/a>). This might indicate an artificial origin of these unusual abundances.<\/p>\n 6.\u00a0P=0.002:\u00a0<\/strong>The retrograde trajectory of 3I\/ATLAS is aligned to within 5 degrees with the ecliptic plane of the planets around the Sun (see\u00a0here<\/a>). This suggests that the trajectory may have been designed.<\/p>\n II.<\/em><\/strong>\u00a0Medium anomalies, which could be a statistical fluke:<\/em><\/strong><\/p>\n 1.\u00a0P=0.006:<\/strong>\u00a03I\/ATLAS arrived from a direction coincident with the radio \u201cWow! Signal\u201d to within 9 degrees (see\u00a0here<\/a>).<\/p>\n 2.\u00a0P<0.01:<\/strong>\u00a03I\/ATLAS shows extreme negative polarization, unprecedented for all known comets, including 2I\/Borisov (see\u00a0here<\/a>). This unusual polarization may be related to its unusual anti-tail.<\/p>\n III.<\/em><\/strong>\u00a0Minor anomalies, which could potentially be explained by a unique origin:<\/em><\/strong><\/p>\n 1.\u00a0P<0.1:<\/strong>\u00a0The gas plume surrounding 3I\/ATLAS contains only 4% water by mass, a dominant constituent of familiar solar-system comets (see\u00a0here<\/a>). The plume might have resulted from the sunlight releasing the ices and dust that accumulated on the surface of a technological object during its journey through the cold interstellar medium.<\/p>\n 2.\u00a0P<0.1:<\/strong>\u00a0Near perihelion, 3I\/ATLAS brightened faster than any known comet and was bluer than the Sun (see\u00a0here<\/a>). This might be a signature that its engine turned on.<\/p>\n 3.\u00a0P<0.1:<\/strong>\u00a03I\/ATLAS exhibits sunward and anti-solar jets which require an unreasonably large surface area for a natural comet in order to absorb enough sunlight needed to sublimate enough ice to feed the mass flux of these jets (as calculated\u00a0here<\/a>). The jets might originate from technological thrusters.<\/p>\n 4.\u00a0P<0.1:<\/strong>\u00a0The tightly-collimated jets from 3I\/ATLAS maintain orientation across a million kilometers in multiple directions relative to the Sun despite its measured rotation. The jets might originate from technological thrusters.<\/p>\n 5.\u00a0P<0.1:<\/strong>\u00a0Near perihelion 3I\/ATLAS exhibits non-gravitational acceleration which requires massive evaporation for a natural comet (as calculated\u00a0here<\/a>), whereas preliminary images indicate that the object maintained its integrity and did not break up (as discussed\u00a0here<\/a>). Instead, the acceleration might have been produced by an engine.<\/p>\n ***<\/p>\n The probability for the combined occurrence of multiple independent anomalies is the product of their individual probabilities.<\/mark>\u00a0From the above list, it is apparent that 3I\/ATLAS is an extremely rare and mysterious object, especially if it happens to be a natural comet as argued by NASA officials at the press conference on November 19, 2025 (accessible\u00a0here<\/a>).<\/p>\n Regarding the updated ranking of 3I\/ATLAS on the Loeb Scale (as defined\u00a0here<\/a>\u00a0and\u00a0here<\/a>), I would prefer to wait for the flood of new data in the coming weeks before revising my previous value.<\/p>\n In an interview on\u00a0NewsNation<\/em>\u00a0last night (accessible\u00a0here<\/a>), the brilliant Natasha Zouves asked me what data am I most looking for in the coming weeks. I explained that\u00a0a spectroscopic measurement of the speed and composition of the jets<\/mark>\u00a0of 3I\/ATLAS would reveal whether they stem from the sublimation of pockets of ice on the surface of a rock or from technological thrusters.<\/p>\n