Outer solar system faces earlier instability than expected

A research team has determined that the outer solar system may face instability much sooner than previously estimated. While Isaac Newton theorized in 1687 that gravitational interactions between outer planets like Jupiter and Saturn could create chaotic orbits over time, most modern scientists believed the system remained stable for trillions of years.

However, new calculations suggest that the lifespan of the outer planets—Jupiter, Saturn, Uranus, and Neptune—could be reduced by a factor of one billion. Rather than remaining in stable orbits for a trillion years, cosmic chaos may erupt just one billion years after the Sun transitions into a white dwarf.

The driver of this instability is the Sun's own death process. In approximately five billion years, the Sun will expand into a red giant and lose nearly half of its mass. Data from the Gaia space telescope suggests this mass loss will not be a smooth, symmetrical process. Instead, the Sun is expected to shed its outer layers through approximately 4,600 chaotic and irregular outbursts. These irregular ejections will cause the Sun to experience unpredictable recoil, creating cumulative gravitational disturbances that threaten the stability of the outer planets.