Caltech Study Revisions on Outer Planet Lifespans
Previous scientific estimates suggested that the orbits of giant planets would remain stable for about one quintillion years, far beyond the current age of the universe. Isaac Newton and many other scientists historically assumed that the Sun would shed its mass smoothly during its death, transitioning first into a red giant and later into a white dwarf.
Under that older model, Earth, Venus, and Mercury would be consumed as the Sun expands, leaving Mars as the sole survivor. The outer planets—Jupiter, Saturn, Uranus, and Neptune—were projected to survive this phase by doubling their current orbital size as the Sun lost mass. Their eventual disruption was thought likely only after 30 to 100 billion years due to passing stars.
Study challenges timeline by modeling turbulent transitions and random ejections
The new research, published in The Astrophysical Journal Letters under the title “Terminal instability of the solar system triggered by stochastic solar mass loss,” challenges that timeline. Investigators found that the Sun will lose mass through violent and random ejections known as “stochastic kicks” rather than a calm and steady release.
When the Sun eventually becomes a white dwarf several billion years from now, it will cool rapidly and shrink to half its current size. According to the study, this turbulent transition will destabilize the outer planets approximately one billion years after the white dwarf phase begins.
Supercomputer Simulations and Methodology
The solar system is currently 4.57 billion years old, with the Sun retaining about five billion years of life before it expands into a red giant. To map out this distant future, the Caltech team used high-performance supercomputers and hundreds of advanced N-body numerical simulations without artificial intelligence tools.
Researchers built a virtual model containing the Sun, Jupiter, Saturn, Uranus, and Neptune to calculate their velocities and positions over billions of years. The analysis factored in the Sun’s mass loss as episodic, violent, and random bursts, testing hundreds of variations to reach a consensual conclusion.
Why previous models miscalculated the fate of the outer planets
What caused previous models to miscalculate the fate of the outer planets?
Earlier scientific models assumed the Sun would lose mass smoothly and steadily as it transformed into a white dwarf. The new Caltech study models the mass loss as violent, random ejections called stochastic kicks, which trigger gravitational instability much earlier.
Which planets will survive the Sun’s expansion into a red giant?
Mercury, Venus, and Earth are projected to be consumed when the Sun expands. Mars is expected to survive because it orbits far enough away to escape being engulfed by the star.
How long do the outer planets have according to the new study?
The research calculates that Jupiter, Saturn, Uranus, and Neptune will be thrown into structural disorder about one billion years after the Sun completes its transition into a white dwarf.
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