{"id":567357,"date":"2026-07-30T18:55:09","date_gmt":"2026-07-30T18:55:09","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/567357\/"},"modified":"2026-07-30T18:55:09","modified_gmt":"2026-07-30T18:55:09","slug":"astronomers-just-found-the-first-atmosphere-on-a-rocky-exoplanet-in-the-habitable-zone","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/567357\/","title":{"rendered":"Astronomers just found the first atmosphere on a rocky exoplanet in the habitable zone"},"content":{"rendered":"

\t\t\t\t\"A<\/p>\n

\n\t\t\t\t\t\tThe exoplanet LHS 1140 b looms in the foreground as its host star, the red dwarf LHS 1140, shines in the distance in this artist’s illustration. Astronomers recently detected helium escaping the planet’s upper atmosphere, the first atmosphere found around a rocky exoplanet beyond the solar system. Credit: ESO\/spaceengine.org\t\t\t\t\t<\/p>\n

Astronomers have detected helium leaking from a rocky exoplanet, a sign that the planet may have an atmosphere. If confirmed, the finding represents the first such detection around an Earth-like world in its host star\u2019s habitable zone, a groundbreaking discovery in the ongoing search for life on other planets.<\/p>\n

The rocky super-Earth LHS 1140 b is one of two known exoplanets orbiting the star LHS 1140, located roughly 50 light-years from Earth in the constellation Cetus. LHS 1140 is classified as an M dwarf, roughly one-fifth the size of our Sun and less than 1% of its brightness. Using a highly sensitive spectrograph on the Magellan Clay Telescope in the dark skies of Chile\u2019s Atacama Desert, lead author and Harvard Ph.D. candidate Collin Cherubim and his team spotted evidence of LHS 1140 b\u2019s atmosphere in 2024 when the planet crossed in front of its host star from our point of view. That detection confirmed predictions made by Cherubim\u2019s own computer model, developed as part of his Ph.D. research. The study, published July 16 in Science, marks LHS 1140 b as a great candidate for further research on exoplanet habitability.<\/p>\n

\u201cWe tend to think for a planet to be habitable, it has to be mostly rocky, has to have an atmosphere to shield the surface from harmful radiation, but also to keep water present,\u201d Cherubim said in a podcast interview with Science<\/a>. \u201cAnd now we know LHS 1140 b meets those criteria.\u201d<\/p>\n

The M-dwarf trap<\/p>\n

Since the first confirmed exoplanet detection in 1992, scientists have found more than 6,300 exoplanets. But in the search for life, they care most about the ones that might be habitable.<\/p>\n

Most exoplanets, including LHS 1140 b, are found through transit photometry, watching a star dim slightly as a planet crosses in front of it. Gas giants are big, so they\u2019re easy to spot as they create lots of variability even in front of bright Sun-like stars. But gas giants are not candidates for habitability. Rocky planets are small, so they\u2019re harder to catch, unless they orbit a small, dim star. That\u2019s what makes M dwarfs, the most common stars in the galaxy, so useful. A rocky planet blocks a much larger share of an M dwarf\u2019s faint light than it would a star like the Sun, making the transit easy to measure.<\/p>\n

But M dwarfs come with a catch. They flare often and blast out disproportionate amounts of X-ray and ultraviolet radiation, which can heat a nearby planet\u2019s atmosphere until it expands and escapes into space \u2014 a process known as irradiation. As a result, astronomers have found numerous rocky planets around M dwarfs in the habitable zone \u2014 the region around a star where planetary surface temperatures would support liquid water. But until now, none of them had a confirmed atmosphere.<\/p>\n

RELATED: Animal life unlikely around a third of stars in the galaxy, study says<\/a><\/p>\n

The TRAPPIST-1 system<\/a> illustrates the M-dwarf catch-22 well. Perhaps the most promising rocky planets astronomers know of, the seven Earth-sized worlds orbiting this M dwarf about 40 light-years away have been the focus of intense scrutiny in the last few years. The James Webb Space Telescope (JWST) has observed several of the system\u2019s planets, hoping to find a stable atmosphere, but so far to no avail.<\/p>\n

Finding a leak<\/p>\n

Cherubim\u2019s team caught LHS 1140 b\u2019s atmosphere by observing the star as the planet crossed in front of it. During this transit, a small fraction of the star\u2019s light filtered through the planet\u2019s atmosphere. By breaking this light into its component colors (akin to a prism), astronomers can determine what wavelengths the atmosphere was absorbing and what elements are responsible. This technique, called transit spectroscopy, can reveal and characterize the exoplanet\u2019s atmosphere \u2014 or lack thereof.<\/p>\n

In the case of LHS 1140 b, they found helium leaking from the planet\u2019s upper atmosphere during a September 2024 transit. The team also observed LHS 1140 c, a second rocky planet in the system on a tighter orbit that exposes it to roughly five times the radiation LHS 1140 b receives, and found no helium there at all. \u201cIt\u2019s not surprising that the inner planet does not have an atmosphere, because it\u2019s more highly irradiated by the star,\u201d Cherubim said in the interview. \u201cWhereas the outer planet is consistent with the prediction that it should have maintained some primordial atmosphere.\u201d<\/p>\n

That prediction came from a computer model Cherubim built during his Ph.D. research, which found that light gases like hydrogen should escape a small, irradiated planet\u2019s atmosphere faster than heavier helium, leaving helium-rich atmospheres behind as the natural end state for planets like LHS 1140 b.<\/p>\n

The discovery came not from a space-based telescope like JWST but from the ground-based Magellan Clay Telescope (MCT). The Clay telescope\u2019s primary mirror spans 6.5 meters \u2014 identical to Webb\u2019s segmented 6.5-meter primary. But its advantage over JWST lies in the instruments attached to it \u2014 in this case, a spectrograph called WINERED.<\/p>\n

WINERED was designed with the ability to split light very finely into its individual wavelengths. Webb\u2019s Near Infrared Spectrograph has a resolving power \u2014 a metric of this ability \u2014 that tops out at 2,700. WINERED, by comparison, offers resolving powers of roughly 28,000 and 70,000 depending on the mode. \u201cThe James Webb Space Telescope, the resolving power is just at most like a tenth of what this ground-based telescope is,\u201d Cherubim explained in the podcast.<\/p>\n

A world imagined<\/p>\n

While spectroscopy can tell scientists a lot about an exoplanet, it doesn\u2019t give a clear picture of what it would be like to stand on the planet\u2019s surface, assuming it even has one. For that, some imagination is required. \u201cI think it\u2019s really fun in this field to try to be imaginative and sort of picture being on these places,\u201d Cherubim told Science. \u201cIf you were standing on the surface of the planet, the star would appear to be twice the size of the Sun in the sky \u2026 probably a lot more red because it\u2019s a red dwarf.\u201d Because LHS 1140 b is tidally locked, it would also have a permanent day side, a permanent night side, and a permanent twilight band in between.<\/p>\n

LHS 1140 b\u2019s observed mass and radius suggest a rocky world that is not as dense as Earth, Cherubim said. That that means the world likely contains a low-density component like a substantial atmosphere or a lot of water \u2014 or both. Now that the atmosphere is confirmed, Cherubim thinks water is a good bet too.<\/p>\n

To keep its ocean though, LHS 1140 b would need a cold trap \u2014 the same barrier of cold air between Earth\u2019s troposphere and stratosphere that stops our oceans from boiling off. Water vapor rising from a planet\u2019s surface hits this cold layer and freezes, before it can climb high enough to escape.<\/p>\n

\u201cOur modeling suggests there\u2019s a very strong cold trap on this planet that\u2019s even colder than Earth\u2019s cold trap,\u201d he said. If LHS 1140 b ever had water, his models suggest it likely still does, making it a plausible ocean world.<\/p>\n

Future planned observations with JWST will search for molecules like carbon dioxide. It could also search for imbalances in the abundances of different chemicals that could signal that some process \u2014 such as life \u2014 is producing gases faster than they break down. None of that would confirm biology on its own. But with a temperate, rocky, atmosphere-bearing planet just 50 light-years away, LHS 1140 b is now one of the most exciting targets in the search for life.<\/p>\n

Brooks Mendenhall is a staff writer for Astronomy magazine and is based in Chattanooga, Tennessee.<\/p>\n","protected":false},"excerpt":{"rendered":"The exoplanet LHS 1140 b looms in the foreground as its host star, the red dwarf LHS 1140,…\n","protected":false},"author":2,"featured_media":567358,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[4076,256748,85,46,43,141],"class_list":["post-567357","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-exoplanets","tag-habitable-worlds","tag-il","tag-israel","tag-news","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/567357","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=567357"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/567357\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/567358"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=567357"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=567357"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=567357"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}