Solar system stability threatened by irregular solar mass loss

New research from the California Institute of Technology (Caltech) suggests the solar system will become unstable much sooner than previously estimated. While older models predicted that giant planets like Jupiter, Saturn, Uranus, and Neptune could maintain stable orbits for up to a quintillion years, new simulations indicate they may enter chaotic orbits approximately one billion years after the Sun dies.

The study, published in ‘The Astrophysical Journal Letters’, highlights that the Sun will not lose mass in a smooth, gradual manner as once thought. Instead, the Sun is expected to undergo ‘stochastic kicks’—violent and irregular bursts of mass loss—as it transitions from a red giant to a white dwarf. These unpredictable gravitational shifts could disrupt the orbital balance of the outer planets.

In the long term, the Sun's expansion into a red giant will likely engulf Mercury, Venus, and Earth, while Mars may remain as the sole survivor of the inner solar system. Eventually, the Sun will settle as a white dwarf, but the resulting gravitational instability could lead to the outer planets being thrown into chaotic paths or ejected from the system entirely.