Overview
- A peer‑reviewed Letter published on June 19 presented updated stellar and orbital models that show Earth may drift outward instead of being pulled into the Sun during its red‑giant and AGB phases.
- The study finds tidal dissipation inside an expanded Sun is weaker than earlier estimates, which reduces the inward 'braking' that would otherwise draw close planets into the star.
- If the Sun loses enough mass as it swells, the weakened gravity would let planetary orbits expand and could carry Earth beyond the reach of the giant star, a result informed in part by observations of the dying star L2 Puppis.
- Simulations still predict Mercury and Venus will be engulfed, while Mars and Earth are placed in plausible survival scenarios depending on the balance between tides and mass loss.
- The outcome does not mean continued habitability, the result hinges on uncertain future solar mass loss, and researchers say better observations and missions such as ESA's PLATO are needed to narrow the remaining unknowns.