Study Suggests Earth Could Avoid Being Engulfed When Sun Becomes a Red Giant
Researchers say that depending on the Sun's mass-loss rate, Earth may either be drawn inward or migrate outward, potentially surviving the Sun’s red-giant phase.
A new study published in the journal Astronomy and Astrophysics indicates that Earth might not be consumed when the Sun expands into a red giant in about five billion years. The research, led by Mats Esseldeurs of the Institute of Astronomy at KU Leuven, examined stellar evolution models and observations of the dying star L2 Puppis as an analogue for the Sun’s future.
The authors explain that two competing processes will determine Earth’s fate. If tidal forces from the expanding Sun dominate, the planet could be pulled into the star’s envelope. Conversely, if the Sun loses mass rapidly enough through stellar winds, its gravitational grip would weaken, allowing Earth to move outward into a wider orbit. "The fate of Earth depends on a delicate balance between these two effects," Esseldeurs said.
Because the rate at which aging stars shed mass remains uncertain, the team calls for more precise observations to refine predictions. Regardless of the outcome for the planet, the study notes that the Sun’s increasing luminosity will render Earth uninhabitable for humans long before the red-giant phase.
