Solar System Lifespan Cut Short by Dying Sun
Our solar system could be destroyed much sooner than expected as the Sun’s death destabilises planetary orbits, according to a study. The research modelled the solar system’s future as the Sun transitions into a white dwarf. While scientists previously assumed the outer planets might survive for longer even than the universe is expected to last, researchers now suggest those distant worlds are unlikely to last more than a billion years past that transition.
For centuries, astronomers including Isaac Newton thought that the finely balanced gravitational pull between Jupiter and the Sun would eventually unravel planetary stability, according to The Independent. Recent research challenged that view by suggesting both inner and outer planets were relatively safe, with Uranus potentially staying stable for a quintillion years. The new models complicate that picture by demonstrating that the solar system could be destabilized far sooner than previously calculated.
Stochastic Mass Loss Triggers Planetary Chaos
The revised timeline stems from how the dying Sun sheds its mass. When the Sun becomes a white dwarf in about eight billion years, it will rapidly cool and shrink down to almost half of its current mass. Previous estimates assumed the Sun would lose its mass in a smooth, consistent way. Researchers found that the ejections will likely be random in both time and direction, creating gravitational “kicks” that alter planetary orbits.
Those random ejections dramatically increase the likelihood of destabilizing the outer planets. The Independent noted that in 40 percent of the team’s simulations, planets were disrupted or scattered while the Sun was still in its earlier red giant phase. The researchers wrote that their results return the solar system’s dissolution to familiar territory and relocate its cause: “not the slow seep of chaos, nor the chance encounter with a passing star, but the Sun itself, which in dying does not merely enlarge the planetary system it built—it shakes it, and more often than not, spills it.”
Sun Will Become White Dwarf in Eight Billion Years
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When is the Sun projected to become a white dwarf?
Researchers estimate the Sun will transition into a white dwarf star in about eight billion years. -
Which planets will be consumed first during the stellar death?
The sources do not specify which planets will be consumed first. -
How long did previous models estimate the outer planets would survive?
Earlier research assumed giant outer planets might survive for longer even than the universe is expected to last—or theoretically up to a quintillion years for Uranus—after the Sun’s main-sequence phase ended.
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