The Sun's Grand Finale
2. The Stellar Stage is Set for a Dramatic Exit
Our Sun, the life-giver, the warm fuzzy blanket of our solar system, is, sadly, not immortal. In about five billion years, it will have exhausted the hydrogen fuel in its core. This isn't like running out of gas in your car; it's more like triggering a complete meltdown of the engine. The core will contract and heat up, causing the outer layers of the Sun to expand dramatically.
Imagine the Sun ballooning outwards, swallowing Mercury, Venus, and possibly even Earth! Our planet, if it still exists as a solid object at that point, will be scorched beyond recognition. The oceans will boil away, the atmosphere will be stripped off, and any remaining life will be toast. A very, very long-lasting toast. The good news? We probably won't be around to witness it. (Unless someone invents some serious time-traveling, cryogenic freezers. But that's another story.)
Even if Earth manages to avoid being completely engulfed, the dramatic increase in solar radiation will make the surface uninhabitable long before that point. It will be like living inside an industrial oven, constantly set to "broil." Forget about sunblock; you'd need a planetary heat shield just to survive for a few minutes.
After this red giant phase, the Sun will eventually shed its outer layers, forming a beautiful planetary nebula — a glowing shell of gas and dust. At the center of this nebula will be a white dwarf, a small, dense remnant of the Sun's core. This white dwarf will slowly cool and fade over trillions of years, eventually becoming a cold, dark ember in the vast emptiness of space.
