The sun won't "blow up" in the way we typically imagine, like a giant explosion. It will eventually become a red giant, but this process is much slower and less dramatic than a sudden explosion.

Here's a breakdown of what happens:

1. The Sun's Life Cycle: Our sun is a main sequence star, currently fusing hydrogen into helium in its core. This process generates energy and keeps the sun stable.

2. Red Giant Phase: In about 5 billion years, the sun will run out of hydrogen fuel in its core. It will begin to fuse helium, causing the core to shrink and heat up. This heat will cause the outer layers of the sun to expand dramatically, turning it into a red giant.

3. Earth's Fate:

* The sun will become significantly larger. The sun's expanded atmosphere will engulf Mercury and Venus, and possibly even Earth.

* Even if Earth survives being engulfed, it will become uninhabitable. The intense heat from the red giant sun will boil away all of Earth's water and vaporize the atmosphere.

4. The Sun's Final Stages: The sun will eventually shed its outer layers, leaving behind a dense white dwarf star. This white dwarf will slowly cool over billions of years.

In short, while the sun won't explode, the process of it becoming a red giant will be catastrophic for Earth. Life as we know it will be long gone by then.