Supernovae are the most powerful explosions in the universe, unleashing enough energy to outshine galaxies. We have no real metaphor for their power – if the sun were to magically go supernova, it would feel like you were being hit by the energy of a nuclear explosion every second. For weeks.
They methodically go through each stage of the process, explaining the conditions of a supernova and how it would affect the surrounding universe.
A supernova is more like a volcanic eruption followed by a tsunami. At first there is a colorful ball of hot, expanding gas, creating a spectacular cloud that will shine for about a month – but then it doesn’t stop. Hot and dangerous gas rushes outward at speeds of 10,000 km/s through the near vacuum of space, sweeping up the sparse gas of the galaxy. This wall of gas expands for tens of thousands of years and will eventually span up to dozens of light-years until it finally cools off, and disperses its substance back into the galaxy. So what if this star tsunami hits us? Well, the damage depends on how far away it is.
As always, however, they do end on a somewhat positive note.
How worried do you need to be? So should you worry? No! Fortunately, there are only a handful of stars that may explode within 1000 lightyears of earth and none are close enough to be a serious threat. Even better, these stars will probably not go supernova for many millions of years. So you are safe. But there’s no guarantee for the far future. As stars orbit the galaxy, our descendants may find themselves dangerously close to a supernova – but by then a far more advanced and wiser humanity will hopefully be able to just move out of the way.