About 35 years ago (1990), I wrote a science popularization article about the Tunguska event (1908), one of the largest explosions caused by a cosmic body in recent history. In that article, I explored a speculative idea: the possibility that a comet with an unusually high deuterium content could, under extreme conditions, be associated with energetic processes beyond a standard kinetic explosion. To be clear, even back then, in the article itself, I considered both the existence of such "deuterium-rich comets" and the possibility of any kind of thermonuclear reaction to be extremely unlikely. I explicitly rejected both as realistic explanations, presenting it only as a conceptual idea. However, recent observations of the interstellar object 3I/ATLAS report unusually high D/H ratios. In particular, measurements in water (H₂O) indicate a value of about D/H ≈ 0.95% (± 0.06%), which is orders of magnitude higher than typical values in the Solar System. This does not validate any kind of nuclear fusion-based mechanism, of course. But it does raise an interesting question: Could objects with significantly enhanced deuterium content be more common (or at least possible) than previously assumed? Back in 1990, I concluded that such objects likely did not exist. Today, I'm not so sure anymore. For reference, the original article was published in Karma 7, February 1990, titled “El misterio de Tunguska”. I’m curious to hear how current models of interstellar chemistry explain such high D/H ratios, and whether this kind of enrichment has clear formation pathways in cold environments. Recent discovery link: https://arxiv.org/abs/2603.06911 submitted by /u/No_Employer_4700 [link] [comments]