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<\/picture><\/div>Like in any blind date, encounters with interstellar objects can result in dealbreakers following non-negotiable behavior. In a new interview with Gadi Schwartz on NBC News (accessible\u00a0here<\/a>), I divided the seven anomalies of the third interstellar object\u00a03I\/ATLAS<\/a>\u00a0into two classes: those that could be alleviated with upcoming data and those that will remain puzzling forever. Here they are:<\/p>\n Anomalies that could be alleviated or explained away with upcoming data:<\/em><\/p>\n 1.\u00a0Size:<\/strong>\u00a0The diameter of 3I\/ATLAS is larger than 5 kilometers, making its minimum mass of 33 billion tons, larger by a factor of a thousand to a million than the mass of the second and first interstellar objects (as derived\u00a0here<\/a>).<\/p>\n 2.\u00a0Jet:<\/strong>\u00a0The Hubble image of 3I\/ATLAS showed a forward jet of scattered sunlight \u2014 10 times longer than it is wide, pointing towards the Sun (as discussed\u00a0here<\/a>). A weak tail showed up only at the end of August (as reported\u00a0here<\/a>).<\/p>\n 3.\u00a0Unusual chemical composition:<\/strong>\u00a0the plume of gas around 3I\/ATLAS showed much more nickel than iron (as discussed\u00a0here<\/a>\u00a0and\u00a0here<\/a>), as in industrial nickel alloys. Unlike solar system comets, the plume contained mostly carbon dioxide and not water (as reported\u00a0here<\/a>\u00a0and\u00a0here<\/a>).<\/p>\n 4.\u00a0Polarization:<\/strong>\u00a0the light from 3I\/ATLAS showed extreme negative polarization (as reported\u00a0here<\/a>).<\/p>\n Anomalies that will remain puzzling forever:<\/em><\/p>\n 5. The trajectory of 3I\/ATLAS is aligned with the ecliptic plane of planets around the Sun to within 5 degrees (0.2% likelihood), as discussed\u00a0here<\/a>.<\/p>\n 6. The arrival time of 3I\/ATLAS was\u00a0optimized<\/mark>\u00a0to pass near Mars, Venus and Jupiter (0.005% likelihood), as discussed\u00a0here<\/a>.<\/p>\n 7. The arrival direction of 3I\/ATLAS is aligned to within 9 degrees with the \u201cWow! Signal\u201d from August 15, 1977 (0.6% likelihood), as discussed\u00a0here<\/a>.<\/p>\n Dogmatists who insist that 3I\/ATLAS is a comet of natural origin must be held accountable to explain all of these anomalies as results of probable natural processes<\/mark>. The existence of the second category of persistent anomalies implies that I will never rank 3I\/ATLAS lower than 2 on the Loeb Scale (which was defined\u00a0here<\/a>\u00a0and quantified\u00a0here<\/a>).<\/p>\n We must keep in mind the story of the\u00a0<\/mark>Trojan Horse<\/a><\/mark>\u00a0\u2014 where an innocent-looking visit delivered an existential threat to the city of Troy.<\/mark>\u00a0In his\u00a0famous wager<\/a>, Blaise Pascal argued that we must consider God seriously, even if we believe that the likelihood for its existence is small, because the implications of this notion are huge. I argue the same regarding the technological origin of anomalous interstellar objects like\u00a01I\/`Oumuamua<\/a>\u00a0or 3I\/ATLAS. Encountering an interstellar artifact might constitute a black swan event, with a low a priori likelihood but major implications. An international organization must attend to this possibility, as a new white paper recommended to the United Nations\u00a0here<\/a>.<\/p>\n Sunlight deposits gigawatts of power on the surface of 3I\/ATLAS as it approaches a minimum separation of 202 million kilometers from the Sun on October 29, 2025. If 3I\/ATLAS is a natural comet, it may erupt in a flare of outgassing or break up into icy fragments soon. Alternatively, if it is technological \u2014 it may maneuver to benefit from the Sun\u2019s gravitational assist or release probes that could intercept the Earth or other planets owing to its retrograde orbit \u2014 opposite in direction to the motion of the planets around the Sun. During the upcoming months, we should observe 3I\/ATLAS with radio telescopes to check whether the near alignment of its arrival direction with the \u201cWow! Signal\u201d was spurious.<\/p>\n Hopefully, we will learn much more about 3I\/ATLAS in the coming days. Today, October 3, 3I\/ATLAS will pass within its closest distance of 29 million kilometers from Mars. Between October 1\u20137, 2025, NASA\u2019s Mars Reconnaissance Orbiter and ESA\u2019s Mars orbiters Mars Express and ExoMars will observe 3I\/ATLAS. The Mars orbiters will take pictures of 3I\/ATLAS and use their spectrographs to infer the composition of the gas around it.<\/p>\n \u201cA picture is worth a thousand words<\/a>.\u201d The highest resolution image so far (accessible\u00a0here<\/a>) was obtained by the Hubble Space Telescope on July 21, 2025, when 3I\/ATLAS was at a distance of 570 million kilometers from the telescope. This image was taken by a camera that is 20 times farther than the closest approach of 3I\/ATLAS to the Mars orbiters. As a result, the HiRISE camera onboard the Mars Reconnaissance Orbiter will obtain images with a much better spatial resolution of 30 kilometers per pixel. The brightest pixel in the HiRISE image would gauge the surface area of 3I\/ATLAS and therefore its diameter. In a recent paper (accessible\u00a0here<\/a>), I derived that the diameter of 3I\/ATLAS is larger than 5 kilometers \u2014 the width of Manhattan Island. The first recognized interstellar object, 1I\/`Oumuamua, was pancake shaped and 0.1 kilometers in diameter \u2014 the size of a football field (as discussed\u00a0here<\/a>). Why is the third interstellar object a million times more massive than the first one? The HiRISE image might exacerbate or weaken the discrepancy. As I told Gadi at the end of my interview, nature could be more imaginative than script writers in Hollywood.<\/p>\n We should not judge the nature of 3I\/ATLAS by the chemicals evaporated from its surface for the same reason that we should not \u201cjudge a book by its cover<\/a>.\u201d During the month of\u00a0October 2023<\/mark>, it will be difficult to observe 3I\/ATLAS from Earth because of its proximity to the sun in our sky. When you look at the Sun in the coming weeks, keep in mind that 3I\/ATLAS is passing behind it. If 3I\/ATLAS will maneuver towards Earth when it reappears on the other side of the Sun, the financial markets may crash. For now, I eagerly await with optimism that the new data from the Mars orbiters will alleviate these concerns.<\/p>\n