It goes without saying that we could not exist on Earth without the Sun. It provides heat and light that all life on Earth needs to survive. Plants use light from the Sun to generate the very oxygen we breathe. It also creates ocean currents, weather, seasons, and our various climates. What, then, would happen if the Sun exploded?
The Sun Goes Supernova
If the Sun decides to up and explode one day, the resulting blast is known as a supernova. A change in the core would result in the Sun launching most of its mass into space in the largest explosion we’d ever seen.
In actuality, since it takes light some 8 minutes 20 seconds to reach Earth, we would have no clue anything happened to the Sun until that much time had passed. Of course, as soon as the solar debris hits the Earth, the side facing the Sun would vaporize instantly. The side facing away from the Sun would heat up to 15 times the surface of the Sun.
Anyone who miraculously manages to survive would be met with perpetual darkness and a rapidly cooling planet. It would only take a few weeks before the surface of the Earth gets too cold to sustain human life.
Look on the Bright Side
Comparatively speaking, our Sun is actually one of the smaller stars in the Milky Way galaxy. It’s too small to ever be able to go supernova. Scientists estimate that a star needs to be ten times the mass of our Sun to be able to go out in a bang.
The Sun is actually a relatively young star as well, at only 4.6 billion years old. In studying the life cycle of other yellow stars, astronomers estimate the Sun will live at least another 5 billion years.
What Will Happen When the Sun Dies?
Although a long way off, the Sun will go through a transformation as it nears the end of its life. As it uses up the last bits of hydrogen in its core, the Sun’s mass will begin to collapse in on itself. This pressure will superheat its center, pushing all its surface layers outward. The resulting expansion will cause the Sun to grow so large it will completely consume our Earth.
The Sun will remain as a red giant for a few hundred million years as it burns and fuses its helium to survive. Eventually, the Sun will have nothing left to give and will expel its outer layers into the expanse of space. This planetary nebula will remain for approximately 10,000 years and may be used to form new stars and planets.
After the Sun creates a planetary nebula of gas, only a condensed core of carbon and oxygen will remain. This core remnant is known as a white dwarf. The white dwarf will still emit residual heat and light at first, but on a much smaller scale. It will take a few billion years for the white dwarf that was once our Sun will cool completely, leaving nothing but a cold, black sphere.
What Can We Do To Prevent the End of the Sun?
As mentioned earlier, the Sun still has some 5 billion years of life left. It will eventually run out of hydrogen for nuclear fusion, and it will die. There’s simply no way to stop this from happening.
If humanity does some day decide to try to slow down the Sun’s eventual end, there are a couple of theoretical (but certainly not practical) options.
Split the Sun
The Sun is a yellow dwarf star and is only able to utilize the hydrogen in its core for fusion. Red dwarf stars, on the other hand, manage hydrogen much more efficiently and can survive trillions of years before burning out.
We would have to find a way to split the Sun into three equal sections to get it small enough to become a red dwarf. Each piece would survive 100 times longer but would only put out 2% of the heat our Sun currently does.
Adding More Fuel
Another option would be to somehow find a way to add hydrogen to the Sun’s core. It is hydrogen, through nuclear fusion, that keeps the Sun burning splendidly in our sky.
There’s nowhere near enough hydrogen on Earth to add a significant amount of fuel to the Sun, and most of this hydrogen is in our water anyway. Humanity would have to find a way to crash other stars into the Sun. The next nearest star is over 4 light-years away, and then there’s the matter of avoiding catastrophe when the two stars meet.
How Can Humanity Survive the End of the Sun?
Humanity can’t survive the end of the Sun if we stay on Earth. In fact, the Sun is slowly getting hotter and brighter, and it will only be one billion years before the Earth is no longer hospitable for humans.
As the Sun warms, humankind may have some other options to look to in our own Solar System. Some of the ice-covered moons surrounding Jupiter and Saturn will also warm and could become ideal climates to live in.
By this point, we may have invented a way to travel to the stars, unlocking access to the 200 billion stars in our galaxy alone. Most of these stars have planets of their own, and at least some of them could likely sustain life.
We’d be hopelessly lost without the Sun’s heat and light to keep us alive. Without it, humanity would likely not even last a month before the Earth would get too cold. Fortunately, there’s a good chance none of us will be around when the Sun eventually does breathe its last. Perhaps by that point, humans will be exploring other stars from all over the Milky Way galaxy!