{"id":206288,"date":"2025-10-17T10:07:08","date_gmt":"2025-10-17T10:07:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/uk\/206288\/"},"modified":"2025-10-17T10:07:08","modified_gmt":"2025-10-17T10:07:08","slug":"a-sunward-jet-from-3i-atlas-imaged-by-the-two-meter-twin-telescope-by-avi-loeb-oct-2025","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/uk\/206288\/","title":{"rendered":"A Sunward Jet from 3I\/ATLAS, Imaged by the Two-meter Twin Telescope | by Avi Loeb | Oct, 2025"},"content":{"rendered":"<p><a rel=\"noopener follow nofollow\" href=\"https:\/\/avi-loeb.medium.com\/?source=post_page---byline--d37ba1808ed2---------------------------------------\" data-discover=\"true\" target=\"_blank\"><img decoding=\"async\" alt=\"Avi Loeb\" class=\"m fk by bz ca de\" src=\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/08\/1755270368_893_1*upiboNSChj1BIvycXiID7w.png\" width=\"32\" height=\"32\" loading=\"lazy\" data-testid=\"authorPhoto\"\/><\/a>Press enter or click to view image in full size<img alt=\"\" class=\"bi ma ng c\" width=\"700\" height=\"729\" loading=\"eager\" role=\"presentation\"\/>An image of the interstellar object <a class=\"ah nl\" href=\"https:\/\/en.wikipedia.org\/wiki\/3I\/ATLAS\" rel=\"noopener ugc nofollow\" target=\"_blank\">3I\/ATLAS<\/a> from the <a class=\"ah nl\" href=\"https:\/\/ttt.iac.es\/\" rel=\"noopener ugc nofollow\" target=\"_blank\">Two-meter Twin Telescope<\/a> in the Canary Islands, Spain. The image, composed of 159 exposures of 50 seconds each, was taken on August 2, 2025. It shows a faint jet pointed towards the Sun (marked by a purple line), extending out to a projected distance of about 6,000 kilometers from the nucleus (indicated by the crossing point of the thin red lines). The direction away from the Sun (where a generic cometary tail should have pointed), is shown in yellow. (Credit: <a class=\"ah nl\" href=\"https:\/\/www.astronomerstelegram.org\/?read=17445\" rel=\"noopener ugc nofollow\" target=\"_blank\">M. Serra-Ricart et al., October 15, 2025<\/a>)<\/p>\n<p id=\"b4c4\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">The most tantalizing feature of the interstellar object <a class=\"ah nl\" href=\"https:\/\/en.wikipedia.org\/wiki\/3I\/ATLAS\" rel=\"noopener ugc nofollow\" target=\"_blank\">3I\/ATLAS<\/a>, was displayed in an image taken by the Hubble Space Telescope on July 21, 2025 (as reported <a class=\"ah nl\" href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/2041-8213\/adf8d8\/pdf\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a> and analyzed <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2509.07771\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>). The image showed an extended glow pointed towards the Sun. The viewing direction was only 10 degrees away from the direction of 3I\/ATLAS relative to the Sun, implying that if the glow had been viewed sideways, it would be about 10 times longer than it is wide. This was highlighted in a paper I wrote with Eric Keto (accessible <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2509.07771\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>). The 10:1 axis ratio constitutes the geometry of a jet pointed from 3I\/ATLAS towards the Sun.<\/p>\n<p id=\"c3fe\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">As soon as the Hubble image was publicized, comet experts cheered that 3I\/ATLAS behaves as a comet. But their enthusiasm neglected the fact that the image revealed an anti-tail pointing towards the Sun. Realizing this is as shocking as photographing an animal in your backyard which your family members identify as a common street cat, while the image shows a tail coming out of the animal\u2019s forehead. The only attempt to explain this unique quality of 3I\/ATLAS was made in the paper I wrote with Eric Keto (accessible <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2509.07771\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>).<\/p>\n<p id=\"2cf4\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">Comets are characterized by a tail of dust and gas which points away from the Sun. The reason is simple: the solar radiation and solar wind push the dust and gas away from the Sun. If the sunward jet (anti-tail) contained refractory dust particles, as found in familiar comets, then that scattered sunlight would have pushed these particles away from the Sun relative to the massive nucleus of 3I\/ATLAS. Larger dust particles with sizes up to hundreds of micrometers, have a smaller surface area per unit mass and are pushed less effectively by sunlight, but they are also less effective at scattering sunlight. The most effective scattering particles are those with a size comparable to the wavelength of sunlight, about 0.5 micrometer. If such particles were shed by 3I\/ATLAS, they would have definitely showed up in a tail pushed in the direction away from the Sun.<\/p>\n<p id=\"3db0\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">A new image (accessible here) was just reported from the <a class=\"ah nl\" href=\"https:\/\/ttt.iac.es\/\" rel=\"noopener ugc nofollow\" target=\"_blank\">Two-meter Twin Telescope<\/a> (TtT) which <a class=\"ah nl\" href=\"https:\/\/ui.adsabs.harvard.edu\/abs\/2024EPSC...17..631S\/abstract\" rel=\"noopener ugc nofollow\" target=\"_blank\">includes<\/a> two pairs of 0.8 meter telescopes at the Teide Observatory in the Canary Islands, Spain. The image, composed of 159 exposures of 50 seconds each, was taken on August 2, 2025. It shows a faint jet pointed towards the Sun. Similarly to the Hubble image, the jet extends to a projected distance of about 6,000 kilometers from the nucleus.<\/p>\n<p id=\"45aa\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">The existence of an anti-tail (jet) pointed towards the Sun is an anomaly that raises two questions:<\/p>\n<p id=\"0502\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">1. What is the nature of the anti-tail?<\/p>\n<p id=\"c7e0\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">2. Why are comet experts ignoring this anomaly while insisting that 3I\/ATLAS is a familiar comet?<\/p>\n<p id=\"e7d2\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">I am working with Eric Keto on a follow-up paper regarding the first question (based on the physics described <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2509.07771\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>). However, I leave the second question to historians of science.<\/p>\n<p id=\"5ca1\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">The Hebrew word \u201cDayenu\u201d means \u201cIt would have been enough\u201d. Paraphrasing the Dayenu song of Passover (accessible <a class=\"ah nl\" href=\"https:\/\/en.wikipedia.org\/wiki\/Dayenu\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>) \u2014 which Stephen Hawking enjoyed at my home a decade ago, one can summarize the anomalies of 3I\/ATLAS as follows:<\/p>\n<p id=\"4a29\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">1. If 3I\/ATLAS had a sunward jet or anti-tail (see <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2509.07771\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>), Dayenu!<\/p>\n<p id=\"296f\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">2. If 3I\/ATLAS was a million times more massive than 1I\/`Oumuamua and a thousand times more massive than 2I\/Borisov, while moving much faster than both (see <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2509.21408\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>), Dayenu!<\/p>\n<p id=\"ef3a\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">3. If 3I\/ATLAS was aligned in its trajectory within 5 degrees with the ecliptic plane of the planets around the Sun (see <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2507.12213\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>), Dayenu!<\/p>\n<p id=\"a077\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">4. If 3I\/ATLAS had a fine-tuned arrival time, so that it passes within tens of millions of kilometers from Mars, Venus and Jupiter (see <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2507.12213\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>), Dayenu!<\/p>\n<p id=\"97c7\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">5. If 3I\/ATLAS showed a gas plume with nickel but no iron (as found in industrially-produced nickel alloys) and a nickel to cyanide ratio that is orders of magnitude larger than all known comets, including 2I\/Borisov (see <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2510.11779\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>), Dayenu!<\/p>\n<p id=\"5478\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">6. If 3I\/ATLAS showed a gas plume with only 4% water by mass, while comet experts forecasted when it is water rich (see <a class=\"ah nl\" href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/2041-8213\/ae0647\/pdf\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>), Dayenu!<\/p>\n<p id=\"ee34\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">7. If 3I\/ATLAS showed extreme negative polarization, unprecedented for all known comets, including 2I\/Borisov (see <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2509.05181\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>), Dayenu!<\/p>\n<p id=\"e70f\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">8. If 3I\/ATLAS arrived from a direction coincident with the \u201cWow! Signal\u201d to within 9 degrees (see <a class=\"ah nl\" rel=\"noopener nofollow\" href=\"https:\/\/avi-loeb.medium.com\/was-the-wow-signal-emitted-from-3i-atlas-d18d4f0d1f1e\" data-discover=\"true\" target=\"_blank\">here<\/a>), Dayenu!<\/p>\n<p id=\"e857\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">Another new preprint about 3I\/ATLAS (accessible <a class=\"ah nl\" href=\"https:\/\/arxiv.org\/pdf\/2510.13222\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a>), suggested to detect its gaseous plume when it will pass within 8 million kilometers from the <a class=\"ah nl\" href=\"https:\/\/science.nasa.gov\/mission\/europa-clipper\/\" rel=\"noopener ugc nofollow\" target=\"_blank\">Europa Clipper<\/a> and <a class=\"ah nl\" href=\"https:\/\/www.esa.int\/Space_Safety\/Hera\" rel=\"noopener ugc nofollow\" target=\"_blank\">Hera<\/a> spacecraft during the coming month. However, I calculated that since the density of the outflowing gas declines inversely with distance squared, the gas plume would be swept away by the solar wind at a distance that is an order of magnitude smaller than the closest approach distance of 3I\/ATLAS from these two spacecraft.<\/p>\n<p id=\"4235\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">Eventually, the second question raised above will need to be addressed by historians of science. History depends on who writes it. The history of the 21st century will likely be written by AI systems. Hopefully, these AI systems will be not be too indoctrinated by the club of unimaginative scientists who ignore the anomalies of 3I\/ATLAS. If AI historians will be biased by myths rather than facts, we will be justified to unplug them from their power supply.<\/p>\n<p id=\"f49a\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">ABOUT THE AUTHOR<\/p>\n<p>Press enter or click to view image in full size<img alt=\"\" class=\"bi ma ng c\" width=\"700\" height=\"1060\" loading=\"lazy\" role=\"presentation\"\/>(Image Credit: Chris Michel, National Academy of Sciences, 2023)<\/p>\n<p id=\"81d5\" class=\"pw-post-body-paragraph nm nn hl no b np nq nr ns nt nu nv nw nx ny nz oa ob oc od oe of og oh oi oj he bl\">Avi Loeb is the head of the Galileo Project, founding director of Harvard University\u2019s Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011\u20132020). He is a former member of the President\u2019s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of \u201c<a class=\"ah nl\" href=\"https:\/\/www.harpercollins.com\/products\/extraterrestrial-avi-loeb?variant=39935330418722\" rel=\"noopener ugc nofollow\" target=\"_blank\">Extraterrestrial:<\/a> <a class=\"ah nl\" href=\"https:\/\/www.harpercollins.com\/products\/extraterrestrial-avi-loeb?variant=39935330418722\" rel=\"noopener ugc nofollow\" target=\"_blank\">The First Sign of Intelligent Life Beyond Earth<\/a>\u201d and a co-author of the textbook \u201c<a class=\"ah nl\" href=\"https:\/\/www.hup.harvard.edu\/catalog.php?isbn=9780674987579\" rel=\"noopener ugc nofollow\" target=\"_blank\">Life in the Cosmos<\/a>\u201d, both published in 2021. The paperback edition of his new book, titled \u201c<a class=\"ah nl\" href=\"https:\/\/www.harpercollins.com\/products\/interstellar-avi-loeb-1?variant=40982888415266\" rel=\"noopener ugc nofollow\" target=\"_blank\">Interstellar<\/a>\u201d, was published in August 2024.<\/p>\n","protected":false},"excerpt":{"rendered":"Press enter or click to view image in full sizeAn image of the interstellar object 3I\/ATLAS from the&hellip;\n","protected":false},"author":2,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":{"0":"post-206288","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-space"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/206288","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=206288"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/206288\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=206288"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=206288"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=206288"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}