Researchers at the California Institute of Technology (Caltech) have found that the outer planets of our solar system will fall into complete chaos roughly one billion years after the death of the Sun, shrinking their expected lifetime by a factor of one billion compared to earlier models.
How Stochastic Mass Loss Alters the Fate of Gas Giants
Previous calculations long assumed that the orbits of gas giants like Jupiter, Saturn, Uranus, and Neptun would remain stable for around one trillion years, a timespan far exceeding the current age of the universe. Scientists working with high-performance supercomputers and hundreds of complex numerical N-body simulation models wanted to examine how the slow death of the Sun impacts these outer worlds. Historically, astronomers from the time of Isaac Newton forward assumed that the Sun would lose its mass in a steady, uniform stream as it transitions through a Red Giant phase into a White Dwarf. Under that older framework, Earth, Venus, and Mercury would vanish first as the Sun expands, leaving Mars as the sole surviving inner planet due to its distance, while the outer planets were thought to double their orbits safely.
The new findings, published in the Astrophysical Journal Letters under the title “Terminal Instability of the Solar System Triggered by Stochastic Solar Mass Loss,” upend that traditional timeline. Rather than shedding mass in a calm, steady outflow, the modeling indicates the dying star will lose its mass through violent, random bursts known as stochastic shocks. When the Sun becomes a White Dwarf, it cools quickly and shrinks to about half its current size, but this turbulent mass loss destabilizes the outer planets about one billion years later.
Supercomputer Models Replace Centuries-Old Assumptions
The research team built a virtual model mapping the Sun alongside Jupiter, Saturn, Uranus, and Neptun, running hundreds of different simulation variations over billions of years without the use of artificial intelligence tools. These numerical experiments demonstrated that the stochastic ejections break the long-held picture of a serene, distant future for the solar system. While the solar system is roughly 4.57 billion years old and the Sun has about five billion years remaining before it expands into a Red Giant, the ultimate destabilization of the outer planets is now calculated to arrive much sooner than previously computed, occurring roughly one billion years after the White Dwarf phase begins.
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