JWST Spectroscopy of 3I/ATLAS: Isotopic Evidence for a Cold and Distant Origin

JWST Spectroscopy of 3I/ATLAS: Isotopic Evidence for a Cold and Distant Origin | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Physical Sciences - Article JWST Spectroscopy of 3I/ATLAS: Isotopic Evidence for a Cold and Distant Origin Martin Cordiner, Nathan Roth, Marco Micheli, Geronimo Villanueva, and 15 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8930056/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Interstellar objects provide the only directly observable samples of icy planetesimals formed around other stars, and can therefore provide insight into the diversity of physical and chemical conditions occurring during exoplanet formation. Here we report isotopic measurements of the interstellar comet 3I/ATLAS, which reveal an elemental composition unlike any Solar System body. The water in 3I/ATLAS is enriched in deuterium, at a level of D/H = (0.79 +- 0.07)%, which is more than an order of magnitude higher than in known comets, while its range of 12C/13C ratios (144--196 for CO2 and 129--179 for CO) exceeds typical values found in the Solar System, as well as nearby interstellar clouds and protoplanetary disks. Such extreme isotopic signatures indicate formation at temperatures <~30 K in a relatively metal-poor environment, early in the history of the Galaxy. When interpreted with respect to models for Galactic chemical evolution, the carbon isotopic composition implies that 3I/ATLAS accreted roughly 10--12 billion years ago, following an early period of intense star formation. 3I/ATLAS thus represents a preserved fragment of an ancient planetary system, and provides direct evidence for active ice chemistry and volatile-rich planetesimal formation in the young Milky Way. Physical sciences/Astronomy and planetary science/Planetary science/Asteroids, comets and Kuiper belt Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/Astrophysical disks Physical sciences/Astronomy and planetary science/Planetary science/Early solar system Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/Interstellar medium Physical sciences/Astronomy and planetary science/Planetary science/Exoplanets Comets: 3I/ATLAS Interstellar Objects Composition Isotopic Ratios Galactic Chemical Evolution Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Here we report isotopic measurements of the interstellar comet 3I/ATLAS, which reveal an elemental composition unlike any Solar System body. The water in 3I/ATLAS is enriched in deuterium, at a level of D/H = (0.79 +- 0.07)%, which is more than an order of magnitude higher than in known comets, while its range of 12C/13C ratios (144--196 for CO2 and 129--179 for CO) exceeds typical values found in the Solar System, as well as nearby interstellar clouds and protoplanetary disks. Such extreme isotopic signatures indicate formation at temperatures \u003c~30 K in a relatively metal-poor environment, early in the history of the Galaxy. 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