The sun will die, and when it does, so will everything that depends on it.
En los laboratorios de la Agencia Espacial Europea, los científicos han fijado una fecha para el fin del mundo habitable: dentro de diez u once mil millones de años, el Sol agotará su combustible de hidrógeno, se expandirá en una gigante roja y reducirá la Tierra a una roca calcinada antes de colapsar en una enana blanca. Es un cálculo que pertenece tanto a la filosofía como a la astronomía, pues nos recuerda que incluso las constantes más eternas tienen su límite. Vivimos en la juventud estable de nuestra estrella, herederos de un tiempo generoso que supera con creces todo lo que la humanidad ha conocido.
- La ESA ha calculado con precisión astronómica el momento en que el Sol dejará de ser la fuente de vida que conocemos, transformándose en el agente de la extinción total de la Tierra.
- Cuando el hidrógeno solar se agote, el núcleo colapsará y las capas externas se expandirán violentamente, convirtiendo al Sol en una gigante roja capaz de engullir Mercurio, Venus y posiblemente la propia Tierra.
- El calor extremo de esa fase evapora los océanos y esteriliza el planeta mucho antes de que cualquier absorción física ocurra, borrando toda posibilidad de vida tal como la conocemos.
- Tras la gigante roja, el Sol se reducirá a una enana blanca —un cadáver estelar del tamaño de la Tierra pero con casi toda la masa solar— irradiando solo el calor residual de su antigua gloria.
- El sistema solar tiene ya cuatro mil quinientos millones de años, lo que sitúa al Sol en su punto medio: la amenaza es real, pero el tiempo restante supera más del doble la edad de todo lo que ha vivido en la Tierra.
En algún lugar de la maquinaria científica de la Agencia Espacial Europea, los astrónomos han hecho el cálculo que parece casi prohibido: han determinado cuándo el Sol pondrá fin a la habitabilidad de la Tierra. No mañana, ni en mil años, sino dentro de diez u once mil millones de años. La matemática está ahí, y con ella el mecanismo paso a paso del único astro que hemos conocido.
Ahora mismo, el Sol atraviesa su fase de secuencia principal: en su núcleo, los átomos de hidrógeno se fusionan en helio y liberan la energía que nos llega como luz y calor. Lleva así cuatro mil quinientos millones de años, y continuará otros diez u once mil millones más. Vivimos, en otras palabras, en los años seguros de nuestra estrella.
Pero todas las estrellas envejecen. Cuando el hidrógeno comience a escasear, el núcleo se contraerá y las capas externas se expandirán violentamente: el Sol se convertirá en una gigante roja. El calor será tan extremo que los océanos de la Tierra se evaporarán por completo, transformando el planeta en una roca estéril. Mercurio y Venus serán engullidos con certeza; la Tierra podría seguir el mismo destino.
Tras esa fase llegará el acto final: el Sol perderá sus capas externas y colapsará en una enana blanca, un cadáver estelar denso y tenue, no mayor que la Tierra pero con casi toda la masa solar comprimida en esa pequeña esfera, irradiando solo el calor residual de su antigua gloria.
Diez u once mil millones de años es un número que derrota la intuición. La humanidad existe desde hace apenas trescientos mil años; la civilización registrada, unos cinco mil. El tiempo que resta antes de la muerte del Sol supera más del doble la edad de todo lo que ha vivido en la Tierra. Es una prórroga tan vasta que convierte la amenaza en algo casi filosófico. Tenemos tiempo. Y, sin embargo, el cálculo permanece: el Sol morirá, y con él todo lo que depende de su luz.
Somewhere in the vast machinery of the European Space Agency, scientists have done the arithmetic that feels almost forbidden: they have calculated when the sun will kill the Earth. Not tomorrow, not in a thousand years, but in ten to eleven billion years—a span so distant it barely registers as real. Yet the math is there, and with it comes the mechanism, the step-by-step unraveling of the only star we have ever known.
Right now, the sun is in what astronomers call its main sequence phase. In the core, hydrogen atoms fuse into helium, releasing energy that radiates outward as light and heat. This is the sun's middle age, the long stable period where it has burned steadily for the past four and a half billion years and will continue to burn for roughly another ten to eleven billion more. The European Space Agency, drawing on data from its Gaia spacecraft, has pinned down this timeline with the precision that modern astronomy allows. We are, in other words, living in the sun's youth and middle years combined—the safe years.
But all stars age. When the sun's hydrogen begins to run dry, something dramatic happens. The core contracts while the outer layers expand violently outward. The sun will swell into what is called a red giant, a bloated, furious version of itself. The surface temperature will drop even as the total energy output climbs. The heat will become so intense that Earth's oceans will evaporate entirely. The planet will transform from a world of water and life into a scorched, lifeless rock. Before that happens, the sun may actually consume the inner planets altogether—Mercury and Venus will certainly be swallowed, and Earth itself may follow into the stellar furnace.
After the red giant phase comes the final act. The sun will shed its outer layers and collapse inward, becoming a white dwarf—a stellar corpse, dense and dim, no larger than Earth itself but carrying nearly the full mass of the sun compressed into that tiny sphere. It will be, as one Spanish publication described it, a stellar cadaver, still massive but now cold and fading, radiating only the residual heat of its former glory.
The timeline is almost incomprehensibly long. Ten to eleven billion years is a number that defeats intuition. Humanity has existed for roughly three hundred thousand years. Recorded civilization spans perhaps five thousand. The age of the solar system itself is only four and a half billion years old. The time remaining before the sun's death is more than twice the age of everything that has ever lived on Earth. It is a reprieve so vast that it renders the threat almost abstract, almost philosophical. We have time. Vast, unimaginable time. And yet the calculation stands: the sun will die, and when it does, so will everything that depends on it.
Citações Notáveis
The sun will eventually become a stellar corpse with a mass nearly equal to the sun's but compressed to the size of Earth— European Space Agency, citing analysis from El País
A Conversa do Hearth Outra perspectiva sobre a história
When the ESA says the sun will die in ten to eleven billion years, are they certain about that number, or is it a range because they genuinely don't know?
It's a range because stellar evolution isn't a clock you can read to the second. The Gaia spacecraft gives them precise measurements of the sun's current mass, temperature, and composition, and from those they can model how long the hydrogen will last. But stars aren't identical—small variations matter. Ten to eleven billion is their best estimate, not a guess.
You mentioned the sun might swallow Earth. Is that guaranteed, or could Earth somehow escape?
When the sun becomes a red giant, its outer atmosphere will expand far beyond where Earth orbits now. Mercury and Venus will definitely be consumed. Earth's fate is less certain—it depends on how much mass the sun loses as it transitions, and how much that changes Earth's orbit. It might be engulfed, or it might survive as a charred remnant orbiting the white dwarf. Either way, it won't be habitable.
The article mentions the solar system is already four and a half billion years old. Why does that matter?
Because it tells you where we are in the story. The sun is at its midpoint. We're not living in the sun's youth—we're living in its middle age. Half its life is already gone. That's both reassuring and sobering: we have time, but the clock is real.
If Earth becomes uninhabitable when the sun is a red giant, couldn't humans just leave? Move to another planet?
In theory, maybe. But we're talking about ten to eleven billion years from now. That's so far in the future that predicting what human civilization will even be is impossible. The question assumes we'll still exist, still care about Earth, still have the technology to escape. It's more useful to think of this as a fact about the universe's structure, not as a practical problem to solve.
What happens to the other planets when the sun becomes a white dwarf?
They'll still be there, orbiting a dead star. A white dwarf is incredibly dense but no longer radiating the heat that makes planets habitable. Any surviving planets will be frozen, dark, orbiting a stellar corpse. It's the end state of the solar system—not destruction, exactly, but the end of anything we'd recognize as life.