The Sun is expected to expand into a red giant in about 12 billion years, posing a significant threat to life on Earth. As the Sun’s hydrogen fuel is depleted, it will begin to fuse heavier elements, causing its outer envelope to expand and engulf nearby planets. Mercury and Venus will likely be destroyed, while Mars may become more temperate due to the increased habitable zone.
On the other hand, gas giant Jupiter and its moons are expected to benefit from the Sun’s transformation. The habitable zone of the Solar System will move outward, encompassing the Jovian system and potentially making Europa, a icy moon of Jupiter, habitable for an extended period. Scientists estimate that Europa could develop and maintain a tenuous water vapor atmosphere, making it a promising candidate for life.
Studying the Sun’s red giant phase is crucial for understanding the evolution of planetary systems and the fate of exoplanets around similar-type stars. Observations of white dwarf planetary systems offer insights into potentially habitable planets and moons that can be studied by current and upcoming space-based observatories.
In particular, researchers are interested in examining factors affecting a planet’s ability to survive its star’s red giant phase, including changes to planetary bodies and their orbits, and the influence of stellar winds on the planets and their moons. Models predict two scenarios: one where Europa is 2 AU from the expanding Sun, and another where it is 0.8 AU from the expanding Sun.
While the exact fate of Earth remains uncertain, scientists acknowledge that our planet will likely undergo significant changes. The remnants of the Sun’s atmospheric envelope will float away to space, and the solar core will shrink down to become a white dwarf. This process may provide valuable insights into the evolution of our own Solar System and potentially habitable exoplanets.
Source: https://www.universetoday.com/articles/will-europa-become-a-habitable-world-when-the-sun-becomes-a-red-giant