Sun's death will destabilize outer solar system far sooner than thought

A new Caltech-led study finds the Sun's own asymmetric mass ejections during its death will destabilize the outer solar system within about 1 billion years of white-dwarf formation, drastically shortening previous estimates by up to a billionfold. The research, published in Astrophysical Journal Letters, shows episodic, directional kicks from the dying Sun's mass loss—not passing stars—will trigger orbital chaos among Jupiter, Saturn, Uranus, and Neptune. Simulations with ejection masses near 10⁻⁴ solar masses, matching observed white-dwarf recoil velocities, resulted in 96% of systems becoming unstable within 3 billion years, with some disruptions occurring before the white dwarf fully forms. This mechanism may explain the prevalence of "polluted" white dwarfs showing heavy elements, as scattered planetary debris continuously falls onto stellar surfaces. The findings revise prior stability estimates of 30 billion to a quintillion years, though the authors note outcomes are probabilistic, leaving a small chance our solar system remains stable.