"Earth may not be swallowed up by the sun after all", say researchers at KU Leuven

The Earth might not be swallowed by the Sun after all, according to new research led by scientists at KU Leuven. For decades, it was widely believed that as the Sun ages, it would expand into a red giant star, engulfing the inner planets, including Earth. However, recent findings suggest there's a possibility that our planet could escape this fate.

In about five billion years, the Sun will undergo a dramatic transformation. It will swell into a red giant, growing approximately 200 times larger than its current size. During this phase, the Sun will lose a significant portion of its mass, expelling its outer layers into space. This expansion will likely result in Mercury and Venus being consumed by the Sun’s expanding atmosphere, but the fate of Earth has remained uncertain until now.

Researchers from KU Leuven and the French research institute CEA Paris-Saclay have proposed that two opposing forces will influence Earth’s trajectory during this time. On one hand, tidal forces will gradually pull Earth closer to the expanding Sun. On the other hand, the Sun's gravitational pull will weaken due to its mass loss, potentially pushing Earth further away. According to researcher Mats Esseldeurs from the Institute for Astronomy at KU Leuven, the outcome hinges on a delicate balance between these effects. If tidal forces dominate, Earth could be pulled too close to the dying Sun and be consumed. Conversely, if mass loss prevails, Earth might escape into a more distant orbit.

Professor Leen Decin from KU Leuven emphasized that while the models used in the study are significantly more advanced than previous ones, predicting the exact amount of mass the Sun will lose remains challenging. “If the Sun’s gravitational pull toward Earth ends up being stronger than predicted, Earth might not move far enough away and could still be engulfed,” she noted. To gain more certainty, additional observations of similar stars are needed. These observations can help refine predictions about Earth’s future.

The implications of this research extend beyond just the survival of Earth. Long before the Sun reaches its red giant phase, Earth will become uninhabitable due to rising temperatures. Professor Decin explained that life on Earth will not survive the extreme heat long before the Sun begins its expansion. The study highlights the complex interplay of astrophysical processes that determine the ultimate destiny of our planet.

Despite the uncertainty surrounding Earth’s fate, the research provides valuable insights into the dynamic nature of stellar evolution. Scientists continue to explore how stars evolve and how their changes affect planetary systems. As technology advances, future studies may offer clearer answers about whether Earth will ultimately be consumed by the Sun or find a way to escape its grasp. Until then, the question of Earth’s survival remains open, inviting further exploration and observation in the field of astronomy.