This is a long time from now, and it will be a gradual process. Here's what we know:
* The Sun is currently in its main sequence stage: This is the longest stage of a star's life, where it fuses hydrogen into helium in its core.
* In about 5.5 billion years, the Sun will run out of hydrogen in its core: At this point, the core will start to shrink and heat up.
* The shrinking core will cause the outer layers of the Sun to expand: This will make the Sun become a red giant, much larger than it is today.
* The Sun will become significantly cooler and redder: This is why it's called a red giant.
* Eventually, the Sun will shed its outer layers, leaving behind a white dwarf: This is the final stage of the Sun's life.
It's important to note that these are just estimations, and the exact timing of the Sun's red giant stage could vary slightly.
