We know when the sun will end. How much time do we have left?

In 2018, an international team of astronomers found that the sun will turn into a planetary nebula at the end of its days. It will be in about 10 billion years. Before that happens, many other things will happen. In 5 billion years the sun will turn into a red giant. Its core would shrink and the outer layers would expand into the orbit of Mars, thus engulfing Earth (if it still existed then).

But one thing is for sure – by the time that happens, people will no longer be around. Scientists estimate we have about a billion years left, unless we can find a way to move to another place in the universe. This is because the sun increases its brightness by about 10 percent. every billion years. Another increase in brightness will end life on Earth. The oceans would evaporate and the surface of the planet would be too hot for water to exist.

It is difficult yet to determine what will happen to the Sun after the red giant phase. The researchers used computer simulations to determine that, like 90% of stars, the Sun is likely to shrink into a white dwarf. The final act of these transformations will be a planetary nebula.

When a star dies, it releases a mass of gas and dust – known as its atmosphere – into space. It can reach half the mass of the star. This reveals the star’s core that is running out of fuel. Only then did the ejected shell shine brightly for about 10,000 years – a brief period in astronomy. This is what makes planetary nebulae visible, even some at very large distances, measuring tens of millions of light years, said Albert Zijlstra, an astrophysicist at the University of Manchester and one of the study’s authors.

Planetary nebulae are very common throughout the observable universe, incl. The Helix Nebula, Cat’s Eye Nebula, and Annular Nebula. They are called planetary nebulae not because they have anything to do with planets, but because when William Herschel discovered the first of them in the late 18th century, they looked like planets through telescopes at the time.