{"id":312967,"date":"2025-08-02T22:08:11","date_gmt":"2025-08-02T22:08:11","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/312967\/"},"modified":"2025-08-02T22:08:11","modified_gmt":"2025-08-02T22:08:11","slug":"how-close-can-the-juno-spacecraft-get-to-the-interstellar-object-3i-atlas-by-avi-loeb-aug-2025","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/312967\/","title":{"rendered":"How Close Can the Juno Spacecraft Get to the Interstellar Object 3I\/ATLAS? | by Avi Loeb | Aug, 2025"},"content":{"rendered":"<p><a rel=\"noopener follow\" href=\"https:\/\/avi-loeb.medium.com\/?source=post_page---byline--66996354d3ff---------------------------------------\" data-discover=\"true\" target=\"_blank\"><img decoding=\"async\" alt=\"Avi Loeb\" class=\"m fd bx by bz cx\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/04\/1*upiboNSChj1BIvycXiID7w.png\" width=\"32\" height=\"32\" loading=\"lazy\" data-testid=\"authorPhoto\"\/><\/a>Zoom image will be displayed<img alt=\"\" class=\"bh lm mz c\" width=\"700\" height=\"499\" loading=\"eager\" role=\"presentation\"\/>Thrust impulse \u2206V (left vertical axis) and propellant mass (right vertical axis) needed for Juno to come within a range of distances from 3I\/ATLAS (horizontal axis). The launch date is assumed to be September 15, 2025. (Image credit: <a class=\"ag ne\" href=\"https:\/\/lweb.cfa.harvard.edu\/~loeb\/Juno.pdf\" rel=\"noopener ugc nofollow\" target=\"_blank\">Loeb, Hibberd &amp; Crowl 2025<\/a>)<\/p>\n<p id=\"2110\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">In <a class=\"ag ne\" href=\"https:\/\/lweb.cfa.harvard.edu\/~loeb\/Juno.pdf\" rel=\"noopener ugc nofollow\" target=\"_blank\">my latest paper<\/a> with Adam Hibberd and Adam Crowl from July 28, 2025, I proposed using the Juno spacecraft, currently in orbit around Jupiter, to probe the newly discovered interstellar object <a class=\"ag ne\" href=\"https:\/\/en.wikipedia.org\/wiki\/3I\/ATLAS\" rel=\"noopener ugc nofollow\" target=\"_blank\">3I\/ATLAS<\/a>, which will pass on March 16, 2026 within a distance of 53.6 million kilometers from Jupiter.<\/p>\n<p id=\"bc37\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">This is a story of scientific redemption. The Juno mission was destined to crash into Jupiter in mid-September 2025. Instead of giving the spacecraft a push into the abyss of Jupiter\u2019s atmosphere, <a class=\"ag ne\" href=\"https:\/\/lweb.cfa.harvard.edu\/~loeb\/Juno.pdf\" rel=\"noopener ugc nofollow\" target=\"_blank\">our paper<\/a> proposes to extend its scientific lifespan by giving it a push away from Jupiter \u2014 so that by mid-March 2026 Juno will get close to 3I\/ATLAS as it comes near Jupiter. If the remaining propellant is insufficient for a zero-distance intercept (a physical collision!), then a milder burn of Juno\u2019s engine in mid-September 2025 could still bring Juno closer to the path of 3I ATLAS by mid-March 2026.<\/p>\n<p id=\"10e4\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\"><strong class=\"nh gx\">How close can Juno get to 3I\/ATLAS as a function of the available fuel mass?<\/strong><\/p>\n<p id=\"e12f\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">This question became timely after a phone call that I received from Congresswoman <a class=\"ag ne\" href=\"https:\/\/luna.house.gov\/\" rel=\"noopener ugc nofollow\" target=\"_blank\">Anna Paulina Luna<\/a>, who on July 31, 2025 sent <a class=\"ag ne\" href=\"https:\/\/lweb.cfa.harvard.edu\/~loeb\/APL_NASA.pdf\" rel=\"noopener ugc nofollow\" target=\"_blank\">a letter<\/a> to NASA\u2019s leadership encouraging the use of Juno as a probe of 3I\/ATLAS.<\/p>\n<p id=\"d088\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">A close encounter between Juno and 3I\/ATLAS will provide a once-in-a-lifetime opportunity to bring a human-made spacecraft within a short distance from a large interstellar object. The event will also be an unprecedented public outreach opportunity for NASA.<\/p>\n<p id=\"b8cf\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">The next step is for NASA to assess the remaining amount of fuel left in Juno\u2019s engine. Once the fuel reservoir is known, it would be possible to optimize the timing for applying thrust impulses to Juno\u2019s trajectory so as to bring it closest to 3I\/ATLAS in mid-March 2026.<\/p>\n<p id=\"d3c5\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">In anticipation of NASA\u2019s study, we have added new figures to <a class=\"ag ne\" href=\"https:\/\/lweb.cfa.harvard.edu\/~loeb\/Juno.pdf\" rel=\"noopener ugc nofollow\" target=\"_blank\">our paper<\/a> that show the distance of closest approach between Juno and 3I\/ATLAS as a function of the remaining propellant mass that its engine can use.<\/p>\n<p id=\"fa20\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">The above figure suggests that burning a small propellant mass of just 110 kilograms \u2014 which is merely 5.4% of Juno\u2019s initial fuel mass \u2014 on September 15, 2026, will allow Juno to get within a distance of 25 million kilometers from 3I\/ATLAS by March 16, 2026. With more propellant burnt, the minimum distance could shrink significantly.<\/p>\n<p id=\"497d\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">There fuel requirement can be further minimized with the application of more than one impulse. The best propulsion strategy can be finalized after the exact quantity of propellant remaining in Juno is determined. Corrections to Juno\u2019s path might be needed if cometary activity of 3I\/ATLAS is intensified as it comes closer to the Sun and its non-gravitational acceleration will change its expected trajectory.<\/p>\n<p id=\"013c\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">The instruments on Juno, namely a near-infrared spectrometer, magnetometer, microwave radiometer, gravity science instrument, energetic particle detector, radio and plasma wave sensor, UV spectrograph and visible light camera\/telescope, can all be used to probe the nature of 3I\/ATLAS from a close distance, far better than any observatories on Earth.<\/p>\n<p id=\"b1b0\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\">Here\u2019s hoping that NASA will attend to the visionary letter and tweet (accessible <a class=\"ag ne\" href=\"https:\/\/x.com\/RepLuna\/status\/1951379349128815062\" rel=\"noopener ugc nofollow\" target=\"_blank\">here<\/a> with about 300k views within a day) from Congresswoman Luna. The resulting benefits will be great to space science and to understanding our place in our cosmic neighborhood.<\/p>\n<p id=\"1f66\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\"><strong class=\"nh gx\">ABOUT THE AUTHOR<\/strong><\/p>\n<p>Zoom image will be displayed<img alt=\"\" class=\"bh lm mz c\" width=\"700\" height=\"1060\" loading=\"lazy\" role=\"presentation\"\/>(Image Credit: Chris Michel, National Academy of Sciences, 2023)<\/p>\n<p id=\"cdc6\" class=\"pw-post-body-paragraph nf ng gw nh b ni nj nk nl nm nn no np nq nr ns nt nu nv nw nx ny nz oa ob oc gp bk\"><strong class=\"nh gx\">Avi Loeb<\/strong> is the head of the Galileo Project, founding director of Harvard University\u2019s \u2014 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=\"ag ne\" href=\"https:\/\/www.harpercollins.com\/products\/extraterrestrial-avi-loeb?variant=39935330418722\" rel=\"noopener ugc nofollow\" target=\"_blank\">Extraterrestrial:<\/a> <a class=\"ag ne\" 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=\"ag ne\" 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=\"ag ne\" 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":"Zoom image will be displayedThrust impulse \u2206V (left vertical axis) and propellant mass (right vertical axis) needed for&hellip;\n","protected":false},"author":2,"featured_media":312968,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3844],"tags":[70,413,16,15],"class_list":{"0":"post-312967","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-science","9":"tag-space","10":"tag-uk","11":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114961456254733009","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/312967","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=312967"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/312967\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/312968"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=312967"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=312967"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=312967"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}