Here's what will happen:
* Red Giant Phase: In about 5 billion years, the Sun will run out of hydrogen fuel in its core and start burning helium. This will cause the Sun to swell into a red giant, expanding beyond the Earth's orbit.
* Destruction of Inner Planets: Mercury, Venus, and likely Earth will be engulfed and vaporized by the Sun's expanding outer layers.
* Fate of Outer Planets: The outer planets, Mars, Jupiter, Saturn, Uranus, and Neptune, are far enough away that they might survive the red giant phase, but they will be significantly affected by the Sun's increased radiation and heat.
However, it's important to note:
* This process is a long way off. We have billions of years before this happens.
* The Sun will eventually become a white dwarf. After the red giant phase, the Sun will shed its outer layers and become a much smaller, denser white dwarf.
In summary, the Sun's expansion is a natural part of its stellar evolution. While it will eventually destroy the inner planets, this process is incredibly far into the future, and we don't need to worry about it anytime soon.
