Firstly, it's important to clarify that the sun, due to its size, won't explode in the same way a supernova does. Instead, it will swell into a red giant before shedding its outer layers and contracting into a white dwarf. This process will take billions of years, but when it does happen, it will drastically alter our solar system.
In approximately five billion years, as the sun exhausts its hydrogen fuel, helium will begin to accumulate in its core. The gravity-driven pressure on the core will increase, causing it to heat up and eventually ignite the helium, causing the sun to expand dramatically into what's known as a red giant.
The red giant phase is an expansive one – quite literally. The sun will grow so large it may swallow up the inner planets, possibly even reaching Earth. Even if Earth manages to avoid a fiery end within the sun's outer layers, the increase in solar radiation will scorch our planet, rendering it uninhabitable.
This red giant phase will last for a few million years until the sun exhausts its helium fuel. Then, a series of contractions and expansions will occur, with the sun shedding its outer layers and creating a planetary nebula – a beautiful shell of gas and dust illuminated by the hot, exposed core.
The remnant left in the center, a white dwarf, will be about the size of Earth but with a mass similar to the sun. This white dwarf will slowly cool and fade over billions of years, its faint light a ghostly echo of the vibrant star it once was.
The death of the sun will undoubtedly spell the end for life as we know it in our solar system. But by the time this event occurs, it's possible that humanity could have found new homes among the stars, on planets orbiting younger, more stable stars. Or perhaps we will find ways to adapt to the changing conditions, extending our species' presence in a solar system reshaped by the sun's demise.
In the vast timescales of the universe, stars like the sun are born, live, and die, their deaths giving birth to new generations of stars and planets. This cycle of stellar life and death, while a sobering reminder of our own solar system's mortality, is also a testament to the dynamic, ever-changing nature of the cosmos.