Earth may avoid destruction by expanding Sun, new study suggests

Scientists have revised predictions about Earth's demise, suggesting the planet might narrowly escape incineration when the Sun expands into a red giant in about five billion years. Instead of being swallowed, Earth could be propelled into a wider orbit, a scenario previously considered unlikely.

“

If tidal interactions prevail, Earth will be engulfed by the Sun. If, however, the Sun's mass loss prevails, Earth will move to an orbit larger than the radius of its star.

This new outlook stems from a study that re-evaluated the forces at play during the Sun's final stages. For years, the prevailing theory was that tidal gravitational forces would pull Earth closer to the expanding Sun, leading to its destruction. However, researchers now believe these tidal interactions are weaker than previously thought. They propose that the outward push from the Sun's strong solar winds, caused by its significant mass loss as it expands, could counteract the inward pull.

Lead author Mats Esseldeurs, a doctoral student at the University of Leuven in Belgium, explained that Earth's fate hinges on a delicate balance between these opposing forces. "If tidal interactions prevail, Earth will be engulfed by the Sun. If, however, the Sun's mass loss prevails, Earth will move to an orbit larger than the radius of its star," he stated. The study utilized advanced computer models and observations of a nearby star, L2 Puppis, to refine these calculations.

“

Better understanding of tidal physics and the most advanced constraints we have on mass loss allow us to say that Earth could move away from the Sun, contrary to what was previously predicted.

Co-author Dr. Stephane Mathis of CEA Paris-Saclay highlighted the improved understanding of tidal physics and solar mass loss. "Better understanding of tidal physics and the most advanced constraints we have on mass loss allow us to say that Earth could move away from the Sun, contrary to what was previously predicted," he noted. Despite this more optimistic forecast, the researchers emphasize that the outcome is not guaranteed. The difference between survival and destruction is highly sensitive to small changes in estimations, leaving Earth's ultimate destiny uncertain.

“

With the current uncertainties in mass loss rates, the final fate of the Earth remains uncertain.