In the TOI-2796 system, a scorching exoplanet of the hot Jupiter type whirls so close to its star that its year lasts just a few Earth days. Scientists ran a computer model to see what would happen during an encounter with a primordial black hole — an invisible relic from the universe’s first moments. Such objects, predicted by Stephen Hawking, could explain the nature of dark matter, whose existence was hinted at by observations of Vera Rubin.

The three-body dance (star, planet, and black hole) turned out chaotic, just as Henri Poincaré foresaw. Imagine a dog on a leash: the owner-star grips the dog-planet, while the black hole is a passerby with a juicy steak. The encounter ends in one of three ways: the planet tears loose into interstellar space, becoming free-floating; starts circling both; or, in the rarest case, gets captured into orbit around the black hole. A neural network sifted through nearly five hundred scenarios and found that very capture.

Such modeling is crucial for hunting dark matter via stellar wobbles or light bending — gravitational lensing. Astonishingly, if such a black hole zipped through our own system, we wouldn’t notice, the planets would only shift ever so slightly.