I found this story at https://dailygalaxy.com/2025/11/astronomers-first-radio-signal-3i-atlas/ … but not apparently the kind of radio signals one might first think. Astronomers have detected a radio signal emanating from Comet 31/ATLAS. This actually confirms its cometary status – and its interstellar origin. The discovery came from the MeerKAT radio telescope in South Africa. It is looking for radio signals rather than images. It was captured shortly after perihelion. The radio waves contained absorption features consistent with hydroxyl [OH] molecules. This is a tell tale sign 31/ATLAS was emitting water vapour – presumably as a result of solar radiation. In turn, this suggests water ice is a major component of 31/ATLAS.
At https://phys.org/news/2025-11-esa-3iatlas-path-mars.html … ESA pinpoints the path of 31/ATLAS with data from Mars Orbiter probes. The comet came within 29 million miles of Mars on the 3rd of October [2025]. The Mars probe viewed the comet from a new angle and triangulation with data from earth based telescopes created the new version of its predicted path into and out of the solar system.
At https://www.livescience.com/space/comets/new-image-of-other-comet-atlas-reveals-its-breaking-apart-ahead-of-close-approach-to-earth … new images of Comet C/2025K1 , the other comet observed by ATLAS, seems to show it has fragmented as a result of its passage around the Sun. Several parts of the comet, either pieces of solid, or clouds of debris, are now visible. Seen by an Italian observatory. This seems to have a connection with a sudden brightening event of the comet close to the Sun.