What would happen if the sun disappeared? When will the solar system die?

The sun is the lifeblood of our solar system, a blazing star that has held everything together for over 4.6 billion years. But like all things in the universe, even our sun will not last forever. If it were to suddenly vanish, Earth and the other planets would drift into frozen darkness, and life as we know it would end within days. While that scenario is purely hypothetical, scientists do have clear predictions for how the sun will naturally die and what it means for everything orbiting it. From its fiery expansion to its quiet, final phase, the sun's life cycle will dramatically reshape the solar system.

The sun’s lifespan and when it will die

Right now, the sun is in the prime of its life—a stable yellow star converting hydrogen into helium through nuclear fusion in its core. This life-sustaining process has been ongoing for about 4.6 billion years and is expected to continue for approximately another 5 billion years. During this time, the sun maintains the balance between

gravitational collapse

and outward pressure from fusion, allowing it to shine steadily.But this peaceful phase won’t last forever. Once the hydrogen in the sun’s core is depleted, the core will begin to collapse under its own gravity, while the outer layers will expand outward. The sun will swell into a red giant, growing so large that it will engulf Mercury and Venus—and possibly Earth. Even if Earth escapes direct consumption, the intense heat and solar winds will strip it of its atmosphere, boil its oceans, and render it uninhabitable.

After the

red giant phase

, the sun will shed its outer layers in a luminous shell of gas known as a planetary nebula. What remains at its core is a white dwarf—a faint, incredibly dense stellar remnant about the size of Earth but containing half the sun’s mass. This white dwarf will no longer generate energy but will slowly cool and fade over billions of years. During this stage, the solar system will enter a cold, dark era. Though the outer planets such as Jupiter, Saturn, Uranus, and Neptune may continue to orbit the white dwarf, the gravitational shifts from the sun’s mass loss may destabilize their orbits over time.

What comes after: the slow unraveling of the solar system across cosmic time

The death of the sun marks the end of the solar system as we know it, but not its immediate obliteration. What follows is a much longer, quieter process—a cosmic fading rather than a dramatic finale.Over trillions of years, the gravitational glue that once held the planets, moons, and asteroids in neat orbits will begin to loosen. As the white dwarf cools and darkens, gravitational encounters with passing stars or galactic tidal forces may begin to disrupt the delicate balance of the remaining solar system. Planets might be flung out into interstellar space or collide with other objects. Debris fields from ancient moons and comets could spiral away, lost to the void.Some astronomers propose that even more fundamental decay could eventually dismantle the last remnants. According to certain theoretical models, protons—the building blocks of atoms—may not last forever. If proton decay does occur, albeit over timescales of 10³⁴ years or more, all matter will ultimately disintegrate into subatomic particles and radiation. This would mark the true end of everything once held together by the sun's gravity.In essence, the solar system won't end with a bang, but with a whimper stretched across eons. Long after the last light of the white dwarf has faded and its planets drift into the cold emptiness of space, what remains will dissolve into the cosmic background. Time, gravity, and entropy will do what no supernova ever could—silently erase the legacy of our once-bright star system.