{"id":452946,"date":"2026-04-25T08:40:31","date_gmt":"2026-04-25T08:40:31","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/452946\/"},"modified":"2026-04-25T08:40:31","modified_gmt":"2026-04-25T08:40:31","slug":"webb-spots-icy-clouds-on-distant-jupiter-like-exoplanet","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/452946\/","title":{"rendered":"Webb Spots Icy Clouds on Distant Jupiter-Like Exoplanet"},"content":{"rendered":"

Using the NASA\/ESA\/CSA James Webb Space Telescope, astronomers have detected water-ice clouds swirling through the atmosphere of Epsilon Indi Ab, a cold super-Jupiter that challenges existing models of giant planet atmospheres.<\/strong><\/p>\n

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

An artist\u2019s impression of Epsilon Indi Ab with water clouds atop its ammonia-dominated atmosphere. Image credit: E.C. Matthews, MPIA \/ T. M\u00fcller, HdA.<\/p>\n

Epsilon Indi A<\/a> is a K5V star located approximately 12 light-years away from Earth in the southern constellation of Indus.<\/p>\n

Also known as HD 209100 or HIP 108870, the star is between 3.7 and 5.7 billion years old.<\/p>\n

The star is a bit less massive and a bit less hot than our Sun and is orbited by a gas-giant exoplanet several times the mass of Jupiter.<\/p>\n

Known as Epsilon Indi Ab<\/a>, the alien world has as a surface temperature of about 200 to 300 K (between minus 70 degrees Celsius and 20 degrees Celsius).<\/p>\n

The reason the planet is slightly warmer than Jupiter (140 K, minus 133 degrees Celsius) is that there is still a lot of heat remaining from the planet formation phase.<\/p>\n

Over the next billions of years, Epsilon Indi Ab will steadily cool down, eventually becoming colder than Jupiter.<\/p>\n

\u201cThis planet has a considerably greater mass than Jupiter \u2014 the new study fixes its mass at 7.6 Jupiter masses \u2014 but the diameter is about the same as for its solar-system cousin,\u201d said Bhavesh Rajpoot, a Ph.D. student at the Max Planck Institute for Astronomy.<\/p>\n

Using Webb\u2019s Mid-Infrared Instrument (MIRI), Rajpoot and colleagues obtained direct images of Epsilon Indi Ab.<\/p>\n

They also estimated the amount of ammonia present in the planet\u2019s atmosphere.<\/p>\n

\u201cFor Jupiter, both ammonia gas and ammonia clouds dominate the upper layers of the atmosphere that are visible in observations,\u201d they said.<\/p>\n

\u201cGiven its properties, Epsilon Indi Ab was thought to have massive amounts of ammonia gas as well, although not ammonia clouds.\u201d<\/p>\n

\u201cSurprisingly, the photometric comparison showed somewhat less ammonia than expected.\u201d<\/p>\n

The best explanation the astronomers found for this deficit was the presence of thick but patchy water-ice clouds, similar to the high-altitude cirrus clouds in Earth\u2019s atmosphere.<\/p>\n

\u201cIt\u2019s a great problem to have, and it speaks to the immense progress we\u2019re making thanks to Webb,\u201d said Dr. James Mang, an astronomer at the University of Texas at Austin.<\/p>\n

\u201cWhat once seemed impossible to detect is now within reach, allowing us to probe the structure of these atmospheres, including the presence of clouds.\u201d<\/p>\n

\u201cThis reveals new layers of complexity that our models are now beginning to capture, and opens the door to even more detailed characterization of these cold, distant worlds.\u201d<\/p>\n

The findings<\/a> appear in the Astrophysical Journal Letters.<\/p>\n

_____<\/p>\n

Elisabeth C. Matthews et al. 2026. A Second Visit to Eps Ind Ab with JWST: New Photometry Confirms Ammonia and Suggests Thick Clouds in the Exoplanet Atmosphere of the Closest Super-Jupiter. ApJL 1002, L5; doi: 10.3847\/2041-8213\/ae5823<\/p>\n","protected":false},"excerpt":{"rendered":"Using the NASA\/ESA\/CSA James Webb Space Telescope, astronomers have detected water-ice clouds swirling through the atmosphere of Epsilon…\n","protected":false},"author":2,"featured_media":452947,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[270],"tags":[115080,10210,6390,15441,18,199565,199566,199567,6145,18060,10211,9973,19,15444,17,1024,133,451,161557,447,15450],"class_list":["post-452946","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-ammonia","tag-atmosphere","tag-cloud","tag-csa","tag-eire","tag-epsilon-indi","tag-epsilon-indi-a","tag-epsilon-indi-ab","tag-esa","tag-exoplanet","tag-gas-giant","tag-ice","tag-ie","tag-ir","tag-ireland","tag-nasa","tag-science","tag-space","tag-super-jupiter","tag-water","tag-webb"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/116464454180959062","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/452946","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=452946"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/452946\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/452947"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=452946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=452946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=452946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}