{"id":27509,"date":"2025-08-14T11:56:11","date_gmt":"2025-08-14T06:11:11","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=27509"},"modified":"2025-08-14T11:56:14","modified_gmt":"2025-08-14T06:11:14","slug":"comets-water-mirrors-earths-oceans-strengthening-life-origin-theory","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/comets-water-mirrors-earths-oceans-strengthening-life-origin-theory\/","title":{"rendered":"Comet\u2019s Water Mirrors Earth\u2019s Oceans, Strengthening Life-Origin Theory"},"content":{"rendered":"\n

ALMA observations of Halley-type comet 12P\/Pons-Brooks reveal water with the same isotopic signature as Earth\u2019s oceans<\/strong><\/em><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

New observations with the Atacama Large Millimeter\/submillimeter Array (ALMA) have revealed that water in the Halley-type comet 12P\/Pons-Brooks has an isotopic composition virtually identical to that of Earth\u2019s oceans.<\/p>\n\n\n\n

This finding strengthens the theory that comets may have played a crucial role in delivering water, and possibly some of the molecular ingredients for life, to our young planet.<\/p>\n\n\n\n

Earth\u2019s water is thought to have arrived billions of years ago through impacts by comets, asteroids, and meteorites. While previous measurements in many comets showed significant differences from Earth\u2019s water, the new results provide the strongest evidence yet that at least some Halley-type comets carried water with the same chemical \u201cfingerprint\u201d as that found on our planet.<\/p>\n\n\n\n

Using ALMA\u2019s exceptional sensitivity and imaging capabilities, an international team led by Martin Cordiner (NASA\u2019s Goddard Space Flight Center) mapped, for the first time, the spatial distribution of both ordinary water (H\u2082O) and heavy water (HDO, containing deuterium) in a comet\u2019s coma\u2014the cloud of gas surrounding its nucleus. <\/p>\n\n\n\n

These observations, made as 12P\/Pons-Brooks approached the Sun, were combined with infrared measurements from NASA\u2019s Infrared Telescope Facility (IRTF) to determine the ratio of deuterium to hydrogen (D\/H) with unprecedented precision for a comet of this class.<\/p>\n\n\n\n

Remarkably, the D\/H ratio\u2014(1.71 \u00b1 0.44) \u00d7 10\u207b\u2074\u2014is the lowest ever measured in a Halley-type comet and falls at the lower end of all cometary values, matching Earth\u2019s oceans. \u201cComets like this are frozen relics left over from the birth of our solar system 4.5 billion years ago,\u201d said Cordiner. <\/p>\n\n\n\n

\u201cSince Earth is believed to have formed from materials lacking water, comet impacts have long been suggested as a source of Earth\u2019s water. Our new results provide the strongest evidence yet that at least some Halley-type comets carried water with the same isotopic signature as that found on Earth, supporting the idea that comets could have helped make our planet habitable.\u201d<\/p>\n\n\n\n

\u201cBy mapping both H\u2082O and HDO in the comet\u2019s coma, we can tell if these gases are coming from the frozen ices within the solid body of the nucleus, rather than forming from chemistry or other processes in the gas coma,\u201d said NASA\u2019s Stefanie Milam, co-author of the study.<\/p>\n\n\n\n

The detection of faint heavy water signals so close to the nucleus\u2014never before mapped in a comet\u2014was only possible thanks to ALMA\u2019s unmatched imaging power.<\/p>\n","protected":false},"excerpt":{"rendered":"

New observations with the Atacama Large Millimeter\/submillimeter Array (ALMA) have revealed that water in the Halley-type comet 12P\/Pons-Brooks has an isotopic composition virtually identical to that of Earth\u2019s oceans.<\/p>\n","protected":false},"author":2,"featured_media":27510,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[],"class_list":["post-27509","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-space-news"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths.webp",768,429,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-200x200.webp",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-675x377.webp",675,377,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths.webp",750,419,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths.webp",750,419,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths.webp",768,429,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths.webp",768,429,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths.webp",768,429,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths.webp",768,429,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-600x429.webp",600,429,true],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-600x429.webp",600,429,true],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-760x429.webp",760,429,true],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-550x360.webp",550,360,true],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-95x65.webp",95,65,true],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-640x429.webp",640,429,true],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-96x96.webp",96,96,true],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/08\/Comets-Water-Mirrors-Earths-150x84.webp",150,84,true]},"author_info":{"info":["RevoScience"]},"category_info":"Space\/ AstroPhysics<\/a>","tag_info":"Space\/ AstroPhysics","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27509","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=27509"}],"version-history":[{"count":1,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27509\/revisions"}],"predecessor-version":[{"id":27511,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27509\/revisions\/27511"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/27510"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=27509"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=27509"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=27509"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}