Life on our planet is largely determined by one factor: the central star at the center of our planetary system. As creatures with a propensity for curiosity, man asks many questions, and one of them concerns the glowing orb above his head: When does the sun explode?
When does the sun explode?
Thanks to scientific measurements and ever-increasing knowledge of what stars are, this question can be answered quickly: in around five billion years. Then our sun will collapse and possibly end in a supernova. This is not good news for the rocky planets in the inner rings of our solar system.
But why do we actually ask ourselves when the sun will explode? Perhaps it is simply because it makes us aware of the absolute finiteness of our own world. After all, in the eyes of the universe, we’re just a biological coincidence somewhere on a rock-and-mud planet we call home.
It is not decisive when the sun explodes, but what this development will look like up to the final supernova. As astronomers get more and more accurate data on how a supernova occurs, we can make more and more precise statements about the fate of our host star.
From medium-sized star to red giant
Right now our sun is in the main sequence stage or sequence. This means that our star has enough hydrogen to allow nuclear fusion and keep its own core stable. So our sun is still a long way from collapsing.
Our sun is now in the prime of life. It’s already five billion years old, so we really don’t need to worry. The question isn’t when the sun will explode, but what the end will be like.
So in about five billion years it will have used up all its hydrogen. As NASA reports, nuclear fusion will then also end inside the sun. However, because hydrogen is still present in the outer mantle, the star is expanding.
The sun cools down and turns red. The planets Mercury and Venus are the first to be swallowed up by this voracious giant. For the earth, however, the sun has already fallen earlier is a danger. A 2013 study showed that 10 percent more solar radiation is enough to vaporize our oceans. And that could be the case as early as 1.5 billion years. So when the sun explodes is no longer important to us.
The grand finale
Once the hydrogen is gone and the sun expands across the planetary orbits, the grand finale begins. After hydrogen fusion, the sun begins to burn off its leftover helium. At that moment, a dramatic chain reaction begins as the sun gradually forms heavy elements. This continues to destabilize its core until the sun explodes in a supernova.
It has relatively little to do with a big bang. Rather, the dying sun eventually sheds its outer plasma envelope. All this leaves behind a beautiful cosmic fog that unfortunately nobody will see anymore. Inside these clouds remains an Earth-sized object, a white dwarf.
Sources: Delayed onset of runaway and moist greenhouse climates for Earth, In: Geophysical Research Letters; Volume 41, Issue 1, pp. 167-172. Own research, NASA.gov, Space.com