Two stars in a wide binary are like figure skaters bound by an elastic tether. You’d expect the tension to weaken with distance and rotation to slow. But observations show the opposite: distant stars race faster, as if the tether tightens itself. That’s how gravity behaves: it gets stronger when it should fade.

Astronomers sifted through Gaia data, weeding out false pairs and systems with a hidden third body (like a red dwarf). By measuring brightness (photometry) and spectrum (spectroscopy), they determined masses, ages, metallicity, and evolutionary stage of the stars. Numerical simulations showed the accelerations are anomalous, even when adding extra hidden companions.

MOND theory: at accelerations 100 billion times weaker than Earth’s, gravity gets 1.5 times stronger. Dark matter is not needed. Back in the 1970s, Vera Rubin noticed the same strangeness in galaxies. If new telescopes confirm the anomaly, the physics of Newton and Einstein will have to be revised in favor of a more general theory of gravity.