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 reach toward the planets it once warmed — yet new science suggests Earth may not be consumed, but instead drift quietly outward into a wider orbit as its star surrenders mass to the void. A team of astrophysicists, refining models of tidal physics and stellar wind, has found that the Sun's gravitational drag on Earth may be weaker than long assumed, tilting the balance toward escape rather than engulfment. The finding does not alter Earth's fate for the living — oceans will have long since boiled away — but it revises the final sentence of our world's cosmic biography.
- For decades, the scientific consensus held that Earth would be swallowed whole as the Sun expanded into a red giant — a conclusion now under serious revision.
- Two forces are locked in a slow-motion contest: tidal drag pulling Earth inward toward the bloating star, and stellar mass loss weakening the Sun's gravitational grip and nudging Earth outward.
- Advanced computer modeling of tidal dissipation — far more precise than earlier calculations — reveals the inward drag is weaker than previously thought, shifting the predicted outcome toward survival.
- Mercury and Venus remain condemned, their orbits too close to escape the expanding fireball, while Earth and Mars appear likely to drift into wider, safer paths.
- The research, validated against L2 Puppis — a nearby star mirroring the Sun's eventual old age — represents fifteen years of cumulative progress in understanding how dying stars interact with their planets.
Five billion years from now, the Sun will exhaust its fuel and swell into a red giant, then into an even more bloated and unstable form known as an AGB star. For decades, astronomers assumed Earth would spiral inward and be consumed. New research suggests that assumption may be wrong.
The question turns on two competing forces. As the Sun expands, its gravity will generate powerful tidal waves within the star itself — waves that, as they dissipate, create a drag pulling Earth closer to destruction. But the aging Sun will also shed enormous mass through stellar winds, weakening its gravitational hold and allowing Earth to drift outward into a safer orbit. Which force wins determines everything.
Mats Esseldeurs and his team at Belgium's University of Leuven used sophisticated computer models to simulate tidal dissipation in dying stars with unprecedented precision. Their key finding: the inward drag is weaker than scientists had assumed. Mass loss, they concluded, would likely dominate — pushing Earth away rather than pulling it in. To validate the models, the team studied L2 Puppis, a nearby star that resembles what our Sun will one day become, confirming their predictions about tidal behavior and mass loss.
Mars, too, appears likely to escape into a wider orbit. Mercury and Venus will not — their proximity to the Sun seals their fate. After consuming its two innermost planets, the Sun will collapse into a white dwarf, a dense, cooling remnant no larger than Earth itself.
The reprieve for Earth carries a sobering caveat. Long before the red giant phase begins, rising solar radiation will have boiled away the oceans and stripped the atmosphere bare. No life will remain to witness the Sun's final drama. The finding is not a rescue — it is a correction, a reminder that even the universe's last word on our world may be more surprising than we imagined.
Five billion years from now, when the Sun has exhausted its fuel and begins its final collapse, Earth may slip away from the dying star's gravitational grip—a possibility that contradicts what astronomers have believed for decades.
The discovery comes from a team of astrophysicists who have refined their understanding of how massive stars behave in their death throes. When the Sun eventually burns through the hydrogen in its core, it will swell into a red giant, then later transform into what scientists call an AGB star—a bloated, unstable sphere of fusing helium. During this expansion, the Sun's surface will creep closer to Earth's orbit, and the gravitational forces at play will become extraordinarily complex.
Two competing forces will determine Earth's fate. The first is tidal interaction: as the Sun expands, its immense gravity will create powerful tidal waves within the star itself. When these waves dissipate, they will generate a drag effect that pulls Earth inward, toward the expanding surface. This has long been the dominant theory—that Earth would inevitably spiral into the Sun and be consumed. But there is a second force working in the opposite direction. As the Sun ages, it will shed enormous amounts of mass through stellar wind, a constant stream of particles escaping into space. This mass loss will reduce the Sun's gravitational pull, allowing Earth to drift outward into a wider, safer orbit.
Mats Esseldeurs, an astrophysicist at Belgium's University of Leuven, led the research that suggests the balance between these two forces may tip in Earth's favor. His team, publishing their findings in Astronomy & Astrophysics, used advanced computer models to simulate tidal dissipation in dying stars with far greater precision than previous calculations allowed. The key insight was that tidal dissipation in giant stars is weaker than scientists had previously assumed—meaning the inward drag on Earth would be less powerful than once thought.
To test their models, the researchers examined L2 Puppis, a nearby star that resembles what our Sun will become in its old age. By studying this cosmic analog, they could validate their predictions about mass loss and tidal behavior. Stephane Mathis, an astrophysicist at France's CEA Paris-Saclay research center, explained that advances in modeling over the past fifteen years have fundamentally changed what the numbers now show. "The dissipation is lower than previously expected," he said, meaning the Sun's mass loss would likely dominate, pushing Earth away rather than pulling it in.
The implications extend beyond Earth alone. Mars, too, appears likely to escape into a wider orbit. Mercury and Venus, however, will not be so fortunate. Their proximity to the Sun means they will be drawn inexorably into the expanding fireball and destroyed. After consuming its two innermost planets, the Sun will eventually collapse into a white dwarf—an extraordinarily dense remnant no larger than Earth itself, slowly cooling and darkening over eons.
This reprieve for Earth comes with an important caveat: the planet will be utterly uninhabitable long before the Sun's expansion begins. Billions of years before the red giant phase, rising solar radiation will have boiled away the oceans and stripped away the atmosphere. Any life that might have evolved on Earth will have vanished millions of years earlier. The new finding is not a rescue for humanity or for any future civilization, but rather a correction to our understanding of the cosmos—a reminder that the universe's final chapter for our world may be written differently than we thought.
Citações Notáveis
Earth's fate depends on a delicate balance between tidal interactions and the Sun's mass loss—if mass loss predominates, Earth escapes into an orbit larger than the radius of its star.— Mats Esseldeurs, lead author, University of Leuven
The dissipation is lower than previously expected, meaning 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
So Earth survives the Sun's death after all? That seems like good news.
It's good news for the planet itself, though it matters more as a scientific correction than as a practical reprieve. Earth will be a lifeless cinder long before any of this happens.
What changed? Why did scientists get this wrong for so long?
They were working with simpler models of how tides behave inside dying stars. The new computers and fifteen years of better physics let them see that tidal drag is weaker than they'd calculated before. The Sun's mass loss—the wind it sheds—turns out to be the stronger force.
So it's a race between two things pulling in opposite directions.
Exactly. The Sun's gravity trying to drag Earth in, and the Sun's own mass loss trying to push it away. For decades, gravity was assumed to win. Now the math suggests the opposite.
What about the other planets?
Mars escapes too. But Mercury and Venus are too close. They don't get away. The Sun will swallow them.
Does this change how we think about other stars and their planets?
It should. If we've been wrong about our own Sun, we may need to reconsider what happens to planets around other dying stars. The study used a nearby star called L2 Puppis to test the theory, but there's a lot more work to do.