Here's why:
* Hydrogen Fusion: The Sun currently fuses hydrogen into helium in its core, generating energy. This process will continue for billions of years.
* Running Out of Fuel: Eventually, the Sun will run out of hydrogen fuel in its core.
* Expansion: Without the outward pressure from fusion, gravity will cause the Sun's core to collapse. This collapse will heat the core, causing the outer layers of the Sun to expand dramatically, turning it into a red giant.
* Swallowing Earth: As the Sun expands, its outer layers will reach and engulf the Earth.
It's important to note that this event is still billions of years in the future, so we don't have to worry about it anytime soon!
