Study Suggests Earth Could Survive Sun’s 5-Billion-Year Red Giant Expansion

Q: Earth may escape the dying sun, but could one cosmic variable still seal our planet's fiery fate?

Yes. The biggest unresolved variable is how much mass the Sun will lose during its late asymptotic giant branch, or AGB, phase, along with how strongly tidal forces act between the swollen Sun and Earth. The new *Astronomy & Astrophysics* study argues Earth may avoid engulfment because two updated pieces of physics favor survival. Improved tidal models suggest giant stars dissipate tidal energy less efficiently than older calculations assumed, so the Sun may be less able to drag Earth inward. At the same time, observations of the aging Sun-like star L2 Puppis suggest the future Sun could shed substantial mass, weakening its gravity and letting Earth’s orbit drift outward. But the result is not settled. The researchers say Earth’s fate is highly sensitive to the Sun’s actual AGB mass-loss rate, which remains poorly constrained. If the Sun loses less mass than the study’s preferred scenario, Earth’s orbit may not widen enough to stay ahead of the Sun’s expansion and tidal pull. In that case, engulfment could still happen. So the key cosmic variable is not whether the Sun becomes a red giant—that is certain—but whether late-stage mass loss is strong enough to overcome tidal inward drag. Mercury and Venus are still expected to be consumed, while Mars survives in the new simulations. Even if Earth physically escapes, intense radiation from the dying Sun would leave it uninhabitable long before the final outcome is decided.

Q: If Earth survives the sun's expansion, what becomes of our scorched world orbiting a stellar corpse?

If Earth avoids engulfment, it would end up as a dead, scorched planet orbiting the Sun’s remnant: a white dwarf. The new study suggests Earth could survive because the aging Sun may lose enough mass to let Earth’s orbit drift outward faster than stellar tides can drag it inward. But survival in orbit would not mean survival in any meaningful sense. During the Sun’s red giant and later asymptotic giant branch phases, intense heat and radiation would likely boil away the oceans, strip much of the atmosphere, and sterilize the surface long before the Sun reaches its final state. After shedding its outer layers as a planetary nebula, the Sun would collapse into a dense white dwarf. Earth, if still bound to it, would circle much farther out than it does today because the Sun’s mass loss would weaken its gravity. The planet would then be a barren rock around a small, fading stellar corpse, receiving far less light and heat than it does now. That future would still be uncertain. The study stresses that Earth’s fate depends heavily on how much mass the Sun loses during its late giant phases, especially the poorly constrained AGB stage. A lower mass-loss rate could still mean engulfment. Even in the survival scenario, Earth would not be habitable. Over much longer timescales, gravitational nudges from passing stars and the changing architecture of the Solar System could eventually destabilize surviving planets, potentially ejecting Earth into interstellar space.

3 articles · Updated · Interesting Engineering · Jun 20

A new Astronomy & Astrophysics study found Earth may avoid being swallowed when the sun expands into red giant and asymptotic giant branch phases roughly 5 billion years from now.
Updated models show weaker stellar tides and significant solar mass loss could push Earth’s orbit outward enough to stay beyond the sun’s maximum size, reversing many earlier forecasts.
The simulations still engulfed Mercury and Venus, while Mars survived in the scenarios the researchers tested.
The outcome remains uncertain because Earth’s fate is highly sensitive to poorly constrained mass loss during the sun’s late stages; the authors used observations of aging star L2 Puppis to refine estimates.
Even if Earth physically survives, intense solar radiation would likely make it uninhabitable long before the sun’s final expansion.

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Interesting Engineering1d ago

New Study Suggests Earth Could Survive Sun's Final Expansion

X8h ago

According to a new study published in the journal Astronomy & Astrophysics (June 19, 2026), Earth may avoid being swallowed by the expanding Sun during its red giant phase in about 5

Instagram1d ago

How Earth is predicted to end in 5-7 billion years 😳

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Earth may escape the dying sun, but could one cosmic variable still seal our planet's fiery fate?

If Earth survives the sun's expansion, what becomes of our scorched world orbiting a stellar corpse?

2026 Update: Can Earth Escape the Sun’s Red Giant Death? New Science, Survival Metrics, and What It Means for Us

Overview

Recent scientific findings have changed our view of Earth's fate when the Sun becomes a red giant. While older models predicted that Earth would be engulfed, new research shows that as the Sun expands and loses mass through strong stellar winds, its gravity weakens. This causes Earth's orbit to move outward. At the same time, tidal forces between the Sun and Earth affect Earth's path. The latest models suggest that the outward movement of Earth's orbit might be enough to prevent it from being swallowed by the Sun, giving our planet a possible physical survival, even if it becomes uninhabitable.

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