Last October 30, 3I\/Atlas made its closest approach to our star\u2014its perihelion, in scientific terms. By next year, it will already be on its way out of the Solar System. Determined to make the most of this fleeting visit, scientists from Spain\u2019s Institute of Space Sciences turned the Joan Or\u00f3 telescope at Montsec Observatory toward the comet as it drew nearer to the Sun.<\/p>\n
#COMET<\/a> #3IATLAS<\/a> MONITORED TONIGHT from #MontsenyObservatory<\/a>. The antitail keeps being the most relevant feature, but nuclear activity exhibits many active, bended jets \u2014 Dr. Josep M Trigo \u2b50\ud83c\udf1b#PlanetaryDefense #DART HERA (@Josep_Trigo) December 1, 2025<\/a> <\/p>\n Ice volcanoes on an alien world<\/p>\n \u2018We were all surprised,\u2019 said Josep Trigo-Rodr\u00edguez, lead author of a new study awaiting peer review. His team detected multiple cryovolcanoes erupting on the comet\u2019s surface\u2014an astonishing find for an object that didn\u2019t even form in our Solar System. Even more surprising, its chemical makeup looks remarkably similar to the frozen bodies that orbit beyond Neptune<\/a>.<\/p>\n As a comet nears a star, its ice naturally heats up and sublimates into gas, which astronomers can observe and analyse. Cryovolcanism typically occurs on ice-rich worlds like trans-Neptunian objects, where internal heat melts the frozen layers. Just like fiery volcanoes on Earth, these frozen counterparts eject vapor and dust into space.<\/p>\n PRE-PERIHELION STUDY OF #COMET<\/a> #3IATLAS<\/a> with our findings about its spectroscopic similitude with CR carbonaceous chondrites. Manuscript submitted for publication in which we propose it is a #TNO<\/a>-like body experiencing #cryovolcanism<\/a> \u2014 Dr. Josep M Trigo \u2b50\ud83c\udf1b#PlanetaryDefense #DART HERA (@Josep_Trigo) November 25, 2025<\/a> <\/p>\n A resemblance that raises questions<\/p>\n For 3I\/Atlas, the process intensified about 378 million kilometers from the Sun. Scientists believe the cryovolcanism results from chemical corrosion of ancient materials sealed inside the comet. Under solar heat, solid carbon dioxide (CO\u2082) began turning into gas, allowing an oxidizing liquid to seep inward, where it reacted with iron and nickel particles and various sulfides.<\/p>\n To confirm their theory, the researchers compared their data with samples from meteorites known as carbonaceous chondrites. Their analysis showed that 3I\/Atlas<\/a>\u2019s composition closely matches that of a fragment of a trans-Neptunian object retrieved by NASA in Antarctica. Despite its clearly interstellar origin, the comet seems to share the same building blocks as bodies from our own Solar System\u2014possibly similar to those that once helped spark life on Earth. Imagine where that discovery could lead next.<\/p>\n Nathalie Mayer<\/p>\n Journalist<\/p>\n Born in Lorraine on a freezing winter night, storytelling has always inspired me, first through my grandmother’s tales and later Stephen King’s imagination. A physicist turned science communicator, I’ve collaborated with institutions like CEA, Total, Engie, and Futura. Today, I focus on unraveling Earth’s complex environmental and energy challenges, blending science with storytelling to illuminate solutions.<\/p>\n \t\t
Just a transitional #comet<\/a>, our research paper
\u27a1\ufe0fhttps:\/\/t.co\/MAVDRxLWma<\/a>
Outreach text\u2935\ufe0fhttps:\/\/t.co\/K0xqGPyz5v<\/a> pic.twitter.com\/EDamqZvSNO<\/a><\/p>\n
The @arxiv<\/a> preprint:
\u27a1\ufe0fhttps:\/\/t.co\/5h7KhRWJAP<\/a> pic.twitter.com\/KOoS22Bg6n<\/a><\/p>\n![\"mayer-nathalie\"](\"https:\/\/www.futura-sciences.com\/en\/wp-content\/uploads\/2025\/03\/mayer-nathalie.avif\")
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