The vastness of our universe is beyond comprehension. Imagine the longest beach in this world and pick up a handful of sand. That handful represents our galaxy. Now, pick a single grain of sand from that handful, and that is our planet Earth. To put it into perspective, a human being would likely be equal to an atom within that grain of sand. In the grand scheme of things, life is insignificant.
Scientists refer to the celestial object around which our solar system orbits as a star. We call this star the sun, a searing hot ball of fire that emits cosmic radiation capable of destroying all living things in its path. Thankfully, when these rays reach Earth, our ozone layer filters out their harmful components and allows only those that are necessary for life.
Plants harness this energy from the sun to produce food, which animals and humans consume to survive. That's how our whole ecosystem works. However, if our energy source (the sun) were to explode, what would be the consequences?
Understanding the Behavior of the Sun
In order to comprehend the behavior of our sun, it is necessary to grasp the life cycle of stars. A star's lifespan primarily relies on its mass, with larger stars perishing at a faster pace. Stars are born from nebulas, comprised mostly of gases (predominantly hydrogen) and dust.
The nebula's gravity compresses the hydrogen gas, leading to an increase in its rotational velocity, ultimately giving birth to a protostar. As the rotational speed continues to increase, heat is generated, and nuclear fusion commences in the core. The star evolves into a massive, luminous ball of fire and continues to shine for millions or billions of years.
Our sun has been shining brightly for approximately 4.6 billion years, and it is expected to continue to do so for billions of additional years. Nevertheless, it will eventually perish, and it will do so in a spectacular fashion. Consequently, one may wonder what transpires when a star reaches the end of its life.
How a Star Dies
Do you recall the hydrogen present within the nebula that contributed to the formation of the star? This hydrogen is used in a nuclear fusion reaction that generates both heat and helium. Nevertheless, the supply of hydrogen is not limitless, and once it is depleted, the star becomes incapable of producing the heat necessary to maintain its structure.
Consequently, the inner core becomes unstable and begins to contract while the outer core cools and expands. The star's hue, previously bright yellow, transforms into red, and it becomes a red giant. In due course, the helium within the core merges to form carbon. Since our star is a low-mass star, it takes a distinct route from high-mass stars at this point.
After all the helium within the core has fused into carbon, the core collapses, and the star's exterior is expelled in a colossal blast that forms numerous planetary nebulas. The core subsequently cools and transforms into a black dwarf.
What Can it Lead to
Let us envision that the billions of years necessary for the sun to enter its red giant phase have already elapsed, and it is now on the verge of exploding. You may assume that the earth will be instantaneously vaporized when the sun explodes, but that is not the case.
Only the side of the earth facing the sun will be subjected to the heat and debris from the explosion and will be scorched in a matter of seconds. Consequently, the other side will begin to boil due to the impact of the heat.
If some individuals are capable of constructing bunkers robust enough to withstand the blast, they might be able to survive while the remainder of the world perishes in the scorching heat. All surface life would perish. As the impact of the explosion starts to subside, the earth's surface will become extremely cold, with temperatures plummeting to as low as -175 degrees Celsius. Eventually, the earth will fall out of orbit since the black dwarf will lack sufficient gravitational pull to maintain its orbit.
There is a slim chance that we may enter the orbit of another star, but it will take too long for subterranean humanity to survive with limited resources. In short, this is what would occur if the sun exploded tomorrow.