3I/ATLAS Today (Nov. 13, 2025): Interstellar comet’s tail keeps growing, ‘radio signal’ confirmed natural, and a different ATLAS comet fragments
Published Thursday, November 13, 2025 Fresh observations today keep 3I/ATLAS—the third confirmed interstellar object—firmly in the “strange but natural comet” camp. Meanwhile, a different ATLAS‑discovered comet in our solar system, C/2025 K1 (ATLAS), is visibly fragmenting. Here’s what changed today, what didn’t, and how to tell these two “ATLAS comets” apart. ScienceAlert+2NASA Science+2 What’s new today (Nov. 13) The science behind the week’s biggest talking points The “radio signal” explained.MeerKAT detected OH absorption at the familiar radio frequencies used to trace water loss in comets. That’s direct evidence that 3I/ATLAS is venting water as it warms—exactly what a coma should