How the Sun will die and what happens to earth?
The beginning of the end
To understand how the Sun would die, we would first have to know how it actually exists. A star like the Sun is born when huge gas clouds of hydrogen and helium collapse in pressure so high, that its core reaches incredible levels of heat. In this unimaginable heat, hydrogen loses its electrons and begins to merge with helium. To be precise, the Sun is powered by nuclear fusion. This is what fuels heat and light. However, our problem arises when the hydrogen begins to deplete.
So, what happens when Sun runs out of Hydrogen? Since the birth of our solar system, our Sun has been in a relatively stable form. However, when it runs out of hydrogen, it will lose its stable state. It will go on expanding until it burns up all the helium. It will then transform from a yellow to a red burning ball. It would expand to engulf Mercury and Venus, stripping life off the surface of the Earth – becoming what astronomers call the red giant.
It will continue that state for billions of years till it uses up all the hydrogen leaving behind only the helium. The helium would then combine with less energy-giving atoms like oxygen and carbons until even helium is completely depleted. Eventually, gravity would take over, shrinking the sun into a dwarf star – transcending into a planetary nebula.
According to Albert Zijlstra of the University of Manchester, U.K, “When a star dies, it ejects a mass of gas and dust — known as its envelope — into space. The envelope can be as much as half the star’s mass. This reveals the star’s core, which by this point in the star’s life is running out of fuel, eventually turning off and before finally dying.”
But the more important question would be what happens to us when that happens?
The State of Earth
The Sun’s slow death could be the end for some planets while being the beginning for some. There are quite a few possibilities. During the expansionary phase of the red giant, if it gets too close to the earth, it could slow down the orbit of the Earth, gently pulling it in. But if Earth does live through the expansionary phase, it will be only orbiting a dwarf star, just a little bigger than us. Even then, our end still looms. Our earth would most likely crash into the dwarf star due to the gravitational forces at play. Additionally, it could also create life on planets like Pluto.
What may happen to us is still an academic debate. Fortunately, according to astronomers, it would take billions of years. There may not even be life on Earth. A lot of things could happen before the death of the Sun too. Perhaps, we may have moved houses into another planet. Or a slight shift in the orbit of planets may occur. Perhaps our galaxy might collide with another. The possibilities are quite endless. We can never be sure of what may happen until it actually does.