Many astronomers have long believed that Earth will be devoured by the aging Sun in a few billion years. However, a recent study by European researchers presents a different scenario: under certain conditions, our planet might survive the Sun’s massive transformation and continue to orbit the burnt-out star in the future. This conclusion emerges from a study led by astrophysicist Mathias Esseldeurs, published in the journal Astronomy & Astrophysics. The authors stress that the ultimate fate of Earth cannot yet be predicted with certainty, as it critically depends on how the Sun evolves during its final life stages.
Why the Sun Becomes a Threat
Current astrophysical knowledge suggests that in about five billion years, the Sun will exhaust its hydrogen fuel in its core. Following this phase, it will expand into a Red Giant and shed substantial amounts of mass during its twilight stages, ultimately leaving behind a White Dwarf. How this process will affect Earth has sparked significant scientific debate over the years. Previous models typically concluded that our planet would be swallowed by the ever-expanding Sun. Conversely, the new study suggests a different fate: while Mercury and Venus face annihilation, Earth has a reasonable chance of survival under specific conditions. However, the researchers warn that uncertainties surrounding the Sun’s mass loss keep Earth’s fate still ambiguous.
A Contest of Two Forces Determines Earth’s Fate
According to the researchers, whether Earth survives hinges on a delicate balance between two opposing effects. On one hand, the aging Sun loses massive amounts of mass, weakening its gravitational pull and allowing Earth to gradually drift into a wider orbit. On the other hand, tidal forces exerted by the swollen Sun can create a braking effect on the planet, potentially pulling it closer. The outcome of which of these forces prevails will ultimately determine whether Earth is swallowed or manages to escape this fate.
New Models Shift Predictions
Earlier studies typically assumed that tidal forces would dominate, leading to scenarios where Earth would enter the Sun’s outer envelope and be consumed. However, the new investigation employs more advanced calculations regarding tidal forces, revealing a diminished impact. Simultaneously, the Sun’s mass loss could be significant enough to shift Earth’s orbit outward sufficiently. According to this model, Earth may not be engulfed by the aging Sun. After the Sun expands into a Red Giant and later sheds its outer layers, only its hot core as a White Dwarf would remain, which Earth could continue to orbit.
Researchers Omit Any Sense of Relief
Despite the encouraging findings, the authors caution against assuming that Earth’s fate is resolved. There remains considerable uncertainty regarding the mass loss the Sun will incur during its end-of-life phase. If this mass loss turns out to be less than expected, calculations indicate that the probability of Earth ultimately being engulfed by the Sun may indeed increase.
