The cosmos oscillates between predictable stability and wild chaos, unsettling our sensitive brains. In our local solar abode, the stability of the planets “is the question around which celestial mechanics was built.” Presumably even before such words existed, when our ancient relatives wondered about the twinkling fires in the night sky. Millennia later, Isaac Newton, supposedly apple-skinned, suspected that the architecture of our outer planets might fall apart. But modern Uranus mathematics suggests they could remain stable for a quintillion years, more than 70 million times the current age of the Universe. Even considering the evolution of the Sun and extraterrestrial stars arriving from space, the outer planets could remain intact for 100 billion years. Or so it was believed, based on the assumption that our dying Sun, in about six billion years, would lose about half its mass as it slowly turned into a white dwarf. But the outer Solar System’s doomsday may be much, much closer, a new study suggests, because the Sun isn’t quietly going out, it’s kicking and screaming. Well, maybe not so much screaming, but literally kicking. As published in The Astrophysical Journal Letters, theoretical astrophysicists Konstantin Batygin and Jim Fuller of Caltech, and Fred Adams of the University of Michigan, have found evidence that the Sun’s mass loss will not be smooth but turbulent and random, ejected in thousands of individual “kicks.” “The surprise is what happens when smoothness gives way to granularity: you break down the mass loss into discrete ejection events and the picture changes completely,” Batygin told ScienceAlert. “The disappearance of the Solar System was hidden within one of the most reassuring results of celestial mechanics.” Each ejection will push our dying Sun into a slightly different position, changing its gravitational influence on each planet. Possible future architectures of the outer Solar System. (Batygin et al., ApJL, 2026) If such explosions were ejected symmetrically, their gravitational influence could be averaged out. But its randomness can lead to small changes that add up to big shakeups in our distant solar family. The researchers found evidence of such changes in data from the European Space Agency’s recently retired Gaia orbital observatory, which observed vast binary star systems that included white dwarfs. They then simulated various levels of mass loss from our future Sun. The researchers decided that each kick that destroys the Sun can eject one ten-thousandth of its mass into space, or about 33 Earths. This occurs haphazardly over 4,600 ejection events, each of which changes the Sun’s speed by about seven meters (23 feet) per second, like an astronaut sneezing or expelling air from his body and being propelled in the opposite direction. Of the nearly 700 simulations, the focus is primarily on 48 that included the most realistic loss of mass ejected during the Sun’s dying stages. In nearly 80 percent of these scenarios (37 out of 48), the outer planets begin crossing their orbits with each other unexpectedly early, long before the Sun has finished losing its outer layers. In the first of those scenarios, the outer planets are already intermingling in their orbits when the Sun has only lost about 10 percent of its mass. When our Sun has truly transformed into a white dwarf, the outer Solar System ends up in lamentable disarray in 40 percent of the projections. For example, Uranus and Neptune can swap positions and even dip within Jupiter’s orbit, creating planetary chaos comparable to a cosmic combination of duck, duck, goose and a demolition derby. We can also lose our precious jewel. Poor Saturn may be ejected within a few million years, being demoted from our impressive ‘king of the rings’ to an orphaned rogue planet forced to wander deep space for endless eons, or possibly until it is adopted by another star system. The planetary forecast is not promising. “We lose them. In nine out of ten of our simulations, at least one giant planet is launched into interstellar space,” Batygin told ScienceAlert. “This fits with microlensing” In total, in 90 percent of the models, our Solar System self-destructs three billion years after the Sun becomes a white dwarf. Therefore, within less than 10 billion years. This work offers a much bleaker projection than ever: our Solar System could be altered 100 times faster than previously estimated, perhaps even before our Sun turns into a white dwarf. “The instability imagined by Newton is real after all,” the researchers write in their paper. “He was just wrong about the author.” Rather than being gravitationally destroyed by an alien intruder, a growing risk as the Sun loses mass and the planets’ orbits. expand: you will be disturbed internally. As in classical tragedy, the Solar System can be destroyed by the inextricable conditions of our birth and growth. Consequently, who can imagine what will become of us when our home is destroyed? Will our descendants, whatever they may be, watch from distant outposts as our ancient cosmic birthplace unravels? Finally, this work also changes our understanding of the Universe, which is home to countless Sun-like stars. “Ninety-seven percent of stars die this way, and many of the systems that exist are more fragile than ours,” Batygin said. “The silent retirement we imagine for planetary systems is a myth.” The research has been published in The Astrophysical Journal Letters. This article was fact-checked by Rachel Garner and edited by Peter Dockrill. While we take pride in our process, we are human. If you spot an error, please let us know.
