{"id":644931,"date":"2026-10-29T15:14:08","date_gmt":"2026-10-29T15:14:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/644931\/"},"modified":"2026-10-29T15:14:08","modified_gmt":"2026-10-29T15:14:08","slug":"webb-finds-link-between-3i-atlas-and-icy-worlds","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/644931\/","title":{"rendered":"Webb Finds Link Between 3I\/ATLAS and Icy Worlds"},"content":{"rendered":"

When astronomers discovered 3I\/ATLAS, only the third known object ever spotted passing through our Solar System from interstellar space<\/a>, they immediately recognized a rare opportunity.<\/p>\n

The interstellar comets are the cosmic travelers that were formed by other distant stars. After being formed, the interstellar comets wander around the galaxy for millions of years. Eventually, the interstellar comets will pass through our celestial neighborhood. As a result, the interstellar comets are considered valuable messengers since they can carry material from planet-forming systems located at great distances away from ours.<\/p>\n

Now, observations from NASA\u2019s James Webb Space Telescope have provided the most detailed look yet at the icy material streaming off 3I\/ATLAS. The results suggest something unexpected: the icy building blocks that formed around another star may not be so different from those that helped build our own Solar System.<\/p>\n

The findings are published in The Astrophysical Journal Letters.<\/p>\n

Webb telescope detects Methane on interstellar comet 3I\/ATLAS<\/a><\/p>\n

As 3I\/ATLAS approached the Sun, its surface warmed, causing ice trapped inside the comet to vaporize. Escaping gas dragged dust and tiny ice grains into the comet\u2019s surrounding cloud, known as the coma.<\/p>\n

Those grains are of particular interest because they preserve clues about the environment where the comet formed.<\/p>\n

\u201cInterstellar comets are small icy bodies that formed in the disks of gas and dust around other stars and are now passing through our solar system,\u201d said Dr. Silvia Protopapa of Southwest Research Institute, lead author of the study.<\/p>\n

\u201cAs 3I\/ATLAS warms up, gas escaping from its interior carries ice and dust grains into the surrounding cloud, or coma. Those grains hold clues to the conditions where the comet was born.\u201d<\/p>\n

NASA\u2019s Webb just traced a mysterious interstellar comet\u2019s ancient origins<\/a><\/p>\n

To investigate those clues, researchers used Webb\u2019s Near-Infrared Spectrograph during three separate observing campaigns between August 2025 and April 2026. Water ice leaves distinctive fingerprints in infrared light.<\/p>\n

Normally, astronomers expect to see a strong absorption feature near 3 microns, along with two additional signatures near 1.5 and 2.0 microns.<\/p>\n

But 3I\/ATLAS didn\u2019t behave as expected. The 3-micron signal was strong, clearly indicating the presence of water ice. Yet the shorter-wavelength signatures were weak or missing.<\/p>\n

\u201cThat combination was a puzzle,\u201d Protopapa said. \u201cThe strong 3-micron band points to water ice in the coma. But the weak or absent shorter-wavelength bands suggest the ice is not in the form we usually see in solar system comets<\/a>.\u201d<\/p>\n

The unusual pattern hinted that the comet\u2019s ice grains differed from those seen in most familiar comets. To solve the mystery, the team compared the observations with detailed computer models.<\/p>\n

The best explanation was that the grains consist of water ice heavily mixed with dust and are extraordinarily small, about a micron across or less. For comparison, a human hair is roughly 70 times wider.<\/p>\n

Growing Tail of Interstellar Comet 3I\/ATLAS Captured<\/a><\/p>\n

\u201cThe grains of 3I\/ATLAS are about the same size as those in our own comets,\u201d Protopapa said. \u201cWhat seems to set them apart is how much dust is mixed into the ice.\u201d<\/p>\n

The researchers also found signs that the grain population evolved over time. By the final observations in April 2026, after the comet had passed closest to the Sun, the data suggested the presence of an additional group of somewhat larger, ice-rich particles.<\/p>\n

\u201cWe can\u2019t yet tell whether the changes over time are the result of the Sun heating the grains differently at each observation, or of new material exposed as the comet\u2019s surface<\/a> eroded near the Sun,\u201d said Dr. Michael Kelley of the University of Maryland.<\/p>\n

\u201cBoth are possible, and telling them apart is one of the open questions we aim to address.\u201d<\/p>\n

The biggest surprise came when researchers compared 3I\/ATLAS to objects much closer to home. The comet\u2019s infrared signature closely resembled that of several trans-Neptunian objects<\/a>, icy bodies orbiting beyond Neptune that preserve material from the early Solar System.<\/p>\n

These distant worlds also exhibit strong 3-micron water-ice features while lacking the stronger 1.5- and 2.0-micron signatures typically seen in comets.<\/p>\n

Astronomers find unexpected organic molecules in interstellar comet 3I\/ATLAS<\/a><\/p>\n

\u201cAt first glance, 3I\/ATLAS looks different from the icy comets we know,\u201d Protopapa said.<\/p>\n

\u201cBut when we placed it alongside distant icy worlds in our own solar system, it no longer looked out of place. This suggests that the icy building blocks of planets<\/a>, here and around other stars, may share ice in the form of tiny, micron-scale grains, ranging from relatively pure ice to ice mixed with dust, with 3I\/ATLAS toward the dusty end.\u201d<\/p>\n

This would suggest that the ice-bearing grains produced in planet-forming disks<\/a> around other stars have a similar distribution of physical characteristics. If this is indeed correct, then there would be a great degree of similarity among the basic components used to construct planets throughout the galaxy.<\/p>\n

The idea remains tentative, based on observations of a single interstellar visitor. But it offers a rare glimpse into the chemistry and structure of material born around another star.<\/p>\n

\u201cWe designed this program to be ready the moment an active interstellar comet was found and to follow it over time,\u201d said Dr. Martin Cordiner of NASA\u2019s Goddard Space Flight Center.<\/p>\n

\u201cOur goal was to characterize the ice, dust, and gas that the comet releases, and so learn about the chemistry and formation of planetesimals, the building blocks of planets<\/a>, around other stars.\u201d<\/p>\n

As Webb and future observatories continue studying interstellar visitors, astronomers hope to learn whether 3I\/ATLAS is unusual or representative of a broader population.<\/p>\n

For now, this tiny wanderer from another planetary system is offering a remarkable message: the ingredients that built distant worlds may not be all that different from the ones that built our own.<\/p>\n

Journal Reference:<\/p>\n

Silvia Protopapa, Michael S. P. Kelley, Martin A. Cordiner, Stefanie N. Milam, Dennis Bodewits, Steven B. Charnley, Maria N. Drozdovskaya, Sara Faggi, Davide Farnocchia, Aur\u00e9lie Guilbert-Lepoutre. JWST Reveals Refractory-rich Water Ice in Interstellar Comet 3I\/ATLAS: Evidence for a Continuum of Grain Properties across Protoplanetary Disks. The Astrophysical Journal Letters. DOI: 10.3847\/2041-8213\/aea60d<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"When astronomers discovered 3I\/ATLAS, only the third known object ever spotted passing through our Solar System from interstellar…\n","protected":false},"author":2,"featured_media":644932,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[22869,6249,111,139,69,9507,147,3145,23272],"class_list":["post-644931","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-comets","tag-neptune","tag-new-zealand","tag-newzealand","tag-nz","tag-planet-formation","tag-science","tag-solar-system","tag-universe"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/644931","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=644931"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/644931\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/644932"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=644931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=644931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=644931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}