{"id":61026,"date":"2025-09-13T05:27:08","date_gmt":"2025-09-13T05:27:08","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/61026\/"},"modified":"2025-09-13T05:27:08","modified_gmt":"2025-09-13T05:27:08","slug":"what-we-know-about-interstellar-comet-3i-atlas","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/61026\/","title":{"rendered":"What We Know about Interstellar Comet 3I\/ATLAS"},"content":{"rendered":"

After 1I\/\u02bbOumuamua and 2I\/Borisov, 3I\/ATLAS is the third object and the second comet from outside the Solar System confirmed.<\/strong><\/p>\n

\"This<\/a><\/p>\n

This image from the Multi-Object Spectrograph (GMOS-N) at the Gemini North telescope shows the interstellar comet 3I\/ATLAS. Image credit: International Gemini Observatory \/ NOIRLab \/ NSF \/ AURA \/ K. Meech, IfA & U. Hawaii \/ Jen Miller & Mahdi Zamani, NOIRLab.<\/p>\n

3I\/ATLAS was discovered by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) on July 1, 2025.<\/p>\n

Also known as C\/2025 N1 (ATLAS) and A11pl3Z, the comet arrived from the direction of the constellation Sagittarius.<\/p>\n

Its orbit is the most dynamically extreme of any object yet recorded in the Solar System.<\/p>\n

\u201cIt might not be aliens making first contact, yet 3I\/ATLAS, as only the third documented interstellar object to pass through the Solar System, still has plenty to teach us,\u201d said Northeastern University astronomer Jacqueline McCleary.<\/p>\n

\u201cInterstellar objects, which all seem to be comets, are the only things that we\u2019ve ever gotten physical observations for within our Solar System that originated outside the Solar System. This is sort of like a messenger afar.\u201d<\/p>\n

\u201cThere are so few interstellar objects that we\u2019ve detected in our Solar System, and they each seem to be unique,\u201d said Michigan State University astronomer Adina Feinstein.<\/p>\n

\u201c3I\/ATLAS gives us an opportunity to study other solar systems up close and personal, without actually needing to visit them.\u201d<\/p>\n

The moment astronomers discovered 3I\/ATLAS, it was clear it was not a normal comet. For starters, it seemed to be emitting its own light, which is bizarre for a comet that was, at that time, so far from the Sun.<\/p>\n

Comets are normally extremely dark to the point where astronomers struggle to see them.<\/p>\n

As they get closer to the Sun, solar radiation causes volatile compounds and ices on their outside, which are highly reflective, to melt.<\/p>\n

The resulting effect is, at first, a kind of proto-tail called a coma, which grows into the tail we have come to associate with comets streaking through the night sky.<\/p>\n

\u201cJupiter is 5 AU or five Earth-Sun distances away from the Sun, and most comets have to get closer than that for the solar radiation to get intense enough to start this melting, outgassing tail creation,\u201d Dr. McCleary said.<\/p>\n

\u201cComet 3I\/ATLAS formed a coma when it was outside the orbit of Jupiter, at a much greater distance than was normal.\u201d<\/p>\n

For 3I\/ATLAS to have started glowing as far out from the Sun as it did was abnormal enough to result in some theorizing early on that it must be an alien spacecraft. What else that small and quick would be producing light?<\/p>\n

However, subsequent observations revealed it not only had a comet-like tail but that it was likely rich in carbon dioxide\u201cbecause carbon dioxide ice, aka dry ice, melts very easily<\/p>\n

The NASA\/ESA\/CSA James Webb Space Telescope ultimately revealed the comet was unique for reasons that went beyond its interstellar origins.<\/p>\n

Not only was it made of carbon dioxide, but it had a carbon dioxide ice-to-water ice ratio that was literally out of this world, 8:1, which is among the highest ever recorded.<\/p>\n

It offers a potential glimpse into the conditions that exist in other solar systems and how those systems formed in the first place.<\/p>\n

\u201cClearly, the 3I\/ATLAS parent system maybe was really rich in carbon dioxide or maybe there were weird radiation processes that left a lot of carbon dioxide and boiled away everything else,\u201d Dr. McCleary said.<\/p>\n

\u201cIndirectly, trying to understand the composition of this comet and comparing it to the composition of other interstellar comets \u2026 can tell us about what solar system formation looks like in other solar systems at a really granular level.\u201d<\/p>\n

It\u2019s still unclear where precisely 3I\/ATLAS originated from.<\/p>\n

\u201cIt likely came from the Milky Way bulge, but tracing its exact origin will be difficult,\u201d Dr. McCleary said.<\/p>\n

\u201cIn order for it to have escaped its parent solar system, the comet must have encountered a gravitational perturbation that disrupted its orbital path and set it on course to enter our Solar System.\u201d<\/p>\n

However, scientists could get an even more detailed glimpse of the comet when it crosses the orbit of Jupiter on its outward-bound path after October, revealing more about its nature.<\/p>\n

NASA\u2019s Jupiter-orbiting Juno satellite will be in the best position to put eyes on the interstellar visitor.<\/p>\n

\u201cWe could potentially get a very close look at that comet, and it could be particularly interesting because it will have gone as close to the sun as it\u2019s going to get and lots of carbon dioxide will have boiled off \u2026 so we\u2019ll be able to see what\u2019s left,\u201d Dr. McCleary said.<\/p>\n

Learning more about 3I\/Atlas will not only be useful for understanding what other solar systems are like, but why our Solar System is so unique that it created the conditions for sentient life to exist.<\/p>\n

\u201cIt\u2019s a window into what the pristine material is for other solar systems, which is precious, and, in turn, helps us refine our models of what solar system formation can look like,\u201d Dr. McCleary said.<\/p>\n

\u201cIs our Solar System common or rare? It seems to be relatively rare, and this helps us quantify that.\u201d<\/p>\n

\u201cLearning about other solar systems places humanity into context,\u201d Dr. Feinstein said.<\/p>\n

\u201cOne of life\u2019s greatest questions is \u2018are we alone in the Universe?\u2019 Each NASA mission gets us a little bit closer to answering this big, overarching question.\u201d<\/p>\n

\u201cCapturing as many observations from the prediscovery period, where 3I\/ATLAS may be in telescope images but wasn\u2019t previously identified, is essential to our understanding of how these objects \u2018turn on\u2019 as they approach our Sun,\u201d said Auburn University astronomer John Noonan.<\/p>\n

\u201cThese interstellar objects have likely not been warmed significantly in millions, if not billions, of years, and any opportunity to see how they responded to that early heating is of interest.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"After 1I\/\u02bbOumuamua and 2I\/Borisov, 3I\/ATLAS is the third object and the second comet from outside the Solar System…\n","protected":false},"author":2,"featured_media":61027,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[270],"tags":[10866,7043,18,19,10881,10867,17,133,10214,451],"class_list":{"0":"post-61026","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-3i-atlas","9":"tag-comet","10":"tag-eire","11":"tag-ie","12":"tag-interstellar-comet","13":"tag-interstellar-object","14":"tag-ireland","15":"tag-science","16":"tag-solar-system","17":"tag-space"},"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/61026","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=61026"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/61026\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/61027"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=61026"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=61026"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=61026"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}