How long would it take for the sun to burn out? Do we have a backup plan?

Answer

Dear Jan,

The sun, as you probably know, is a star, and a star is nothing more than a nuclear power station, which gets its energy from the nuclear fusion of hydrogen. This process can only take place at the very high temperatures near the center of the star (millions of degrees Celsius). The fuel will run out there one day, and then the star will be done for. Our sun will run out of fuel in about five billion years. The result is that the core shrinks, and the outside (due to the law of action and reaction) expands. Such an object is called a red giant. The sun will then become so large that the earth may be swallowed up and at least scorched. Finally, the outer layers of the sun are completely blown away, leaving a dead, cooling object in the center: a white dwarf. But that’s not all for tomorrow! At present, humanity is unable to create a star of its own or to move to another star system. Whether this will be the case within one billion years (because by then it will already be too hot here for living beings) is rather a philosophical question. You make the assumption that humanity will still exist by then, which is absolutely not certain.