Earth could move away from the Sun, contrary to what was predicted before
Five billion years hence, the Sun will swell into a dying giant and, for generations, astronomers assumed Earth would be swallowed whole. New mathematical modeling now suggests our planet may instead drift outward into safety, carried by the very mass the Sun sheds in its final age. The discovery does not alter any human fate — all life will be long gone before the question is answered — but it quietly revises our understanding of how worlds and stars part ways, and whether destruction is truly the only ending written into the cosmos.
- For decades, Earth's incineration by the expanding Sun was treated as settled science — a cosmic death sentence with no appeal.
- Advanced tidal physics models have cracked open that certainty, revealing that tidal forces pulling Earth inward may be weaker than long assumed.
- Two forces now compete for Earth's fate: the Sun's gravity dragging the planet closer, and solar wind pushing it outward as the dying star sheds its mass.
- Mars may also escape into a wider orbit, but Mercury and Venus have no such chance — they are already condemned by their proximity.
- The research, validated against a nearby star called L2 Puppis, repositions planetary survival from impossibility to a matter of delicate, calculable balance.
Five billion years from now, the Sun will exhaust its fuel and swell into a red giant, then into an even larger dying star that dwarfs the inner solar system. For generations, astronomers assumed this expansion would consume Earth — gravity pulling the planet inward until it was swallowed by the star's outer layers. A study published Friday in Astronomy & Astrophysics now challenges that assumption.
The key lies in a competition between two forces. As the Sun bloats, its gravity will tug Earth closer — the same mechanism that drives our ocean tides. But the dying star will also shed vast quantities of mass through stellar wind, and that mass loss pushes Earth outward into a wider, safer orbit. Which force prevails determines whether Earth survives. According to Mats Esseldeurs of Belgium's University of Leuven, the outcome hinges on a delicate equilibrium between the two.
The breakthrough came from fifteen years of refinements to how scientists model tidal forces inside giant stars. The new calculations show that tidal dissipation is weaker than previously thought, shifting the balance toward survival. Astrophysicist Stephane Mathis of France's CEA Paris-Saclay noted that Earth could now move away from the Sun, contrary to earlier predictions. The team tested their models against L2 Puppis, a nearby star in an advanced stage of evolution, using its observed mass loss to sharpen their projections.
Mars appears likely to escape alongside Earth, while Mercury and Venus — orbiting too close — remain doomed. After the Sun collapses into a white dwarf, it will cool over trillions of years into a dark, cold remnant. None of this offers comfort to the living: all life on Earth will have vanished billions of years before the red giant phase even begins. But the finding quietly rewrites a chapter of planetary science, suggesting that escape from a dying star may be built into the physics of stellar evolution itself.
Five billion years from now, when the Sun exhausts its fuel and begins to die, Earth may slip away from its fatal embrace—a possibility that contradicts what scientists have believed for decades.
The discovery emerged from a study published Friday in Astronomy & Astrophysics, the result of refined mathematical models that track what happens to planets as their star undergoes the violent transformations of old age. When the Sun finally burns through the hydrogen in its core, it will swell into a red giant, then later into an even larger AGB star—a bloated, incandescent sphere that will dwarf the inner solar system. For generations, astronomers assumed this expansion would be Earth's end: our planet, pulled inward by gravitational forces, would be consumed by the dying star's outer layers.
But the new calculations suggest a different outcome is possible. The fate of Earth, according to Mats Esseldeurs of Belgium's University of Leuven, hinges on a delicate equilibrium between two competing forces. As the Sun swells, its immense gravity will tug Earth closer, much as the Sun's gravity today creates the tides in our oceans. Yet simultaneously, the dying star will shed enormous quantities of mass through stellar wind—a constant stream of particles blown outward into space. This mass loss will actually push Earth away, into a wider, safer orbit. Which force wins determines whether Earth survives or perishes.
The breakthrough came from advances in how scientists model tidal forces within giant stars. For fifteen years, researchers have refined their understanding of how energy dissipates within these massive bodies. The new models reveal that tidal dissipation is weaker than previously calculated, which changes the equation entirely. "In the current state of knowledge, Earth could move away from the Sun, contrary to what was predicted before," said Stephane Mathis, an astrophysicist at France's CEA Paris-Saclay centre. The team validated their approach by studying L2 Puppis, a nearby star in an advanced stage of evolution—essentially the Sun's distant cousin—and used observations of its mass loss to refine their projections.
The implications ripple across the inner solar system, though not equally. Mars, like Earth, appears likely to escape into a wider orbit and survive the Sun's death throes. Mercury and Venus, orbiting closer to the star, have no such reprieve. They will be drawn inexorably into the expanding fireball and destroyed. After the Sun exhausts its helium and collapses into a white dwarf—an extremely dense remnant no larger than Earth itself—it will gradually cool and fade over trillions of years, leaving behind a dark, cold cinder.
The timeline is so vast that it offers no practical comfort to anyone alive today. All life on Earth will vanish billions of years before the Sun's red giant phase even begins, whether from the star's increasing heat, the planet's changing orbit, or some other cosmic event. Yet the finding reshapes how scientists understand planetary survival and the long-term architecture of solar systems. It suggests that escape from a dying star, once thought impossible for inner planets, may be written into the physics of stellar evolution itself.
Citações Notáveis
Earth's fate depends on a delicate balance between these two effects. If tidal interactions predominate, Earth is engulfed by the Sun. If the Sun's mass loss predominates, Earth escapes into an orbit larger than the radius of its star.— Mats Esseldeurs, lead author, University of Leuven
In the current state of knowledge, Earth could move away from the Sun, contrary to what was predicted before.— Stephane Mathis, astrophysicist, CEA Paris-Saclay
A Conversa do Hearth Outra perspectiva sobre a história
Why did scientists get this so wrong for so long?
The math was too simple. They had basic models of how tides work inside giant stars, but those models didn't capture the full picture. It took fifteen years of better observations and computing power to see that tidal energy actually dissipates more slowly than anyone thought.
So the Sun losing mass—that's the thing that saves us?
It's one of two things pulling in opposite directions. The Sun's gravity pulls Earth in as it swells. But the solar wind pushes Earth out. For decades, people thought gravity would win. Now we're saying maybe it doesn't.
What about the other planets?
Mars gets lucky too. But Mercury and Venus are too close. They're doomed no matter what. The math is clearer for them.
Does this change anything about what we should do now?
Not really. We'll be long gone before any of this happens. But it does change how we think about planetary systems everywhere—whether planets around other dying stars might survive when we didn't think they could.
So this is more about understanding the universe than about Earth's future?
Exactly. Earth's survival in five billion years is almost academic. What matters is that we've gotten better at reading the physics of stellar death.