Just as yeast turns flour into fluffy dough, radioactive 'seasoning' from a supernova — the explosion of a massive star at the end of its life helps mold a rocky planet. The key ingredient here is aluminum-26, a radioactive isotope that releases heat as it decays. But the dosage must be perfect: too much, and the protoplanetary disk of cosmic dust and gas will be blown away by the shock wave; too little, and the planet remains loose and cold, without a molten interior.

Previously, it was thought that to deliver the necessary materials, the supernova had to explode so close to the forming system that it would inevitably destroy its embryo. However, new research has revealed a more elegant mechanism: it turns out that the invisible rays of the supernova, high-energy neutrinos, thread through the disk and, colliding with matter, 'manufacture' radioactive aluminum-26 right on the spot. This is similar to how the invisible rays of a microwave oven heat food from the inside, but here they don't just heat; they transform one atomic nucleus into another.

Calculations based on models of neutrino flux propagation and nuclear reactions in the protoplanetary disk show that at a distance of about one parsec (that's like to Proxima Centauri), the disk is not destroyed but receives exactly the amount of aluminum-26 found in ancient meteorites — stone witnesses to the birth of the Solar System. Moreover, an analysis of typical stellar nurseries, regions of active star formation, indicates that at least one supernova in them comes within such a distance. So the recipe for forming exoplanets — planets around other stars of Earth-like type is not a cosmic accident but a common rule.

The heat from the decay of aluminum-26, whose half-life is only 717,000 years, melts the planet's interior and triggers differentiation: heavy elements sink to the center, forming the core, while light ones rise to form the crust. Perhaps this is how our Earth came to be — not in the fiery chaos of a close explosion, but thanks to the precise 'seasoning' from a moderately distant supernova.