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The findings are reshaping how planetary systems across the galaxy are understood.<\/p>\n
A colder birthplace<\/p>\n
Near the Sun, interstellar comet 3I\/ATLAS released water carrying a chemical fingerprint that stands apart.<\/p>\n
Luis E. Salazar Manzano, a doctoral student at the University of Michigan<\/a>, tied the comet\u2019s composition directly to conditions unlike those that shaped Earth\u2019s neighborhood.<\/p>\n Its water showed a level of heavy hydrogen enrichment far beyond any known comparison, preserving a record of its earliest formation environment.<\/p>\n Those limits indicate the comet formed under colder and less irradiated conditions, pointing toward processes that differ sharply from those in the solar system.<\/p>\n Water molecules that are heavier<\/p>\n Ordinary water contains hydrogen and oxygen, but deuterium<\/a> \u2013 hydrogen with one extra neutron \u2013 makes some water molecules heavier.<\/p>\n Inside 3I\/ATLAS, that heavier form appears in striking amounts, leaving a chemical mark that survived the comet\u2019s long trip.<\/p>\n The ratio was 30 times higher than any comet measured in our solar system and 40 times higher than Earth\u2019s oceans.<\/p>\n \u201cThe amount of deuterium with respect to ordinary hydrogen in water is higher than anything we\u2019ve seen before in other planetary systems and planetary comets,\u201d Salazar Manzano said.<\/p>\n Chemical traces in comet water<\/p>\n Comets preserve old ice because their frozen interiors can avoid much of the heat that changes planets.<\/p>\n When sunlight warms a comet, sublimation<\/a> \u2013 ice turning directly into gas \u2013 releases molecules from beneath its dusty surface.<\/p>\n The escaping gas forms a cometary coma, the loose cloud around the nucleus, where telescopes can read chemical traces.<\/p>\n By measuring those traces, scientists compare the comet\u2019s water with water from Earth, meteorites, and solar system comets.<\/p>\n A rare visitor<\/p>\n With so few confirmed interstellar visitors, every measurement of 3I\/ATLAS carried unusual scientific weight.<\/p>\n Objects like this likely leave their home systems after planets or passing stars throw them onto open paths.<\/p>\n Because 3I\/ATLAS came from elsewhere, its ice gives scientists direct material from a planetary system they cannot visit.<\/p>\n For a field built mostly on distant light, one passing comet offered rare material from another planetary system\u2019s formation history.<\/p>\n Telescopes captured the comet early<\/p>\n Fast discovery made the study possible because the comet was still bright enough for follow-up observations near the Sun.<\/p>\n The Atacama Large Millimeter\/submillimeter Array (ALMA<\/a>), a network of radio telescopes in Chile, detected heavy water and methanol, a simple alcohol molecule, in the comet\u2019s gas.<\/p>\n Multiple methanol lines helped scientists estimate how much ordinary water escaped, even though ordinary water stayed below direct detection.<\/p>\n Missing that ordinary-water signal made the result more cautious, but the heavy-water enrichment remained the central finding.<\/p>\n A comet with cold origins<\/p>\n A single extra neutron<\/a> may sound minor, yet it records the temperature and radiation around forming ice.<\/p>\n Scientists use the ratio of deuterium to ordinary hydrogen because cold chemistry favors heavier hydrogen in water molecules.<\/p>\n Warmer regions can erase part of that record as molecules break apart, recombine, or mix with more processed material.<\/p>\n Under that chemical logic, 3I\/ATLAS most likely formed in colder, less irradiated conditions than solar system comets.<\/p>\n A mysterious birthplace<\/p>\n Different parts of the galaxy contain slightly different amounts of deuterium in their gas, but not enough to explain this comet.<\/p>\n Galactic history destroys some deuterium inside stars, then returns processed material through winds from stars and exploding stars.<\/p>\n High-energy particles called cosmic rays<\/a> can also change exposed ice, but they probably cannot create this much heavy water in shallow surface layers.<\/p>\n Those limits point back to the comet\u2019s birth environment, not just its long time drifting between stars.<\/p>\n Clues about planetary systems<\/p>\n One possibility places the comet\u2019s water in a prestellar cloud, a cold gas-and-dust region before a star forms.<\/p>\n Disk processing offers another route, because a protoplanetary disk<\/a>, the young disk around a star, can mix warm and cold ice.<\/p>\n Early ejection from that disk could have preserved more unprocessed ice before heat and mixing lowered the heavy-water signal.<\/p>\n Either path leaves the same broad message: planetary systems can build their icy bodies under sharply different conditions.<\/p>\n Future research directions <\/p>\n Future interstellar comets could turn this one result into a wider survey of how water forms around other stars.<\/p>\n New sky-monitoring observatories should find more faint visitors, especially if they detect them early enough for chemical study.<\/p>\n Clear night skies remain part of that effort because light pollution makes tiny moving objects harder to catch.<\/p>\n Keeping those skies dark protects a basic scientific tool: the chance to notice small bodies before they pass beyond reach.<\/p>\n A passing comet has shown that water chemistry can vary sharply from one planetary birthplace to another, even within the same galaxy.<\/p>\n With more discoveries, scientists can test whether 3I\/ATLAS is rare or the first clear example of a broader pattern.<\/p>\n The study is published in the journal Nature Astronomy<\/a>.<\/p>\n Image Credit: International Gemini Observatory\/NOIRLab\/NSF\/AURA\/B. Bolin<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Astronomers have found that an interstellar comet carries water unlike anything measured in comets from our own solar…\n","protected":false},"author":2,"featured_media":406839,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[111,139,69,147,392],"class_list":["post-406838","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-new-zealand","tag-newzealand","tag-nz","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/406838","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=406838"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/406838\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/406839"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=406838"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=406838"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=406838"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}