The Sun, which plays vital role in the solar system, is not immortal. It has limited lifetime like all the other stars in the universe. It will be the end of humanity when the Sun dies but anticipating the changes on the Earth after the Sun’s death might help scientists to find a breakthrough.

What keeps the Sun shine?

It survives by operating fusion reaction by converting hydrogen atoms into helium atoms in its core. This procedure releases a vast amount of energy to keep the Sun glow. According to the Einstein’s mass-energy equivalence formula, one can calculate 4 grams of hydrogen can produce approximately 2.6*10¹¹ joules through fusion reaction, which is equivalent to keeping 60-watt light bulbs shine for over 100 years. Therefore, depletion of hydrogens can result the Sun’s death.

Calculation: (When 4 grams of hydrogen is converted to helium, 2.8*10^-3 grams is converted to energy.)

E = mc²

E = (2.8*10^-3 grams) * c²

E = (2.8*10^-6 kgs) * (3*10⁸m/sec)²

E = 2.6*10¹¹ joules

 

During the Sun’s death

[Image by NASA’s Goddard Space Flight Center/S. Wiessinger via https://www.nasa.gov/content/goddard/nasas-swift-mission-observes-mega-flares-from-a-mini-star]

Despite this huge release of energy, the Sun has limited hydrogens in its core. Scientists believe the Sun will continue to fuel for next 5 billion years, and it will gradually run out of hydrogen. More hydrogen atoms the Sun fuels, more helium atoms it creates. The Sun’s core will shrink due to the accelerated nuclear fusion reaction and its own gravity. Since the Sun is the greatest supporter of the Earth’s biosphere, the Sun’s death will immensely impact the Earth. After 3 billion years from now, the Sun will expand its outer layer and shine 40% brighter. At this rate, the solar wind, the continuous flow of the charged articles released from the Sun, will have higher energy that will turbulent the Earth’s electromagnetic field. The electromagnetic field will no longer be able to protect the Earth by deflecting harmful radiations from the Sun. This will expose all the organisms on the Earth to higher ultraviolet radiation which can trigger cancer. Moreover, the high energy particles will increase the Earth’s temperature excessively. Glaciers and oceans will evaporate. All moisture in the atmosphere will disappear, and the Earth will become severely hot. The Earth will not last as a habitable place for organisms including humans. This will be the beginning of an apocalypse of the Earth.

The situation will continue to aggravate as the time passes. After 5.4 billion years from now, the Sun’s core will exhaust most of the hydrogens. The Sun’s core will contract and become extremely dense. The Sun will become a red giant, and its outer layer will extend millions of miles, which will swallow Mercury and Venus. It can potentially extend to where the Earth is, but even if it does not, the Earth’s surface will still be inhospitable for organisms due to extreme condition. However, organisms might be able to survive if they evacuate into the underground because “UV radiation cannot penetrate into the soil below 5mm” (Bao p.7). This will be the humans’ last-ditch effort to survive. Moving underground may allow humans to buy more time, but they will eventually have to face inevitable apocalypse. Other than moving underground, humanity might find other breakthrough depending on their advancement in scientific technology. The Earth and Mars are currently in the habitable zone of the Sun, but after 5.4 billion years, habitable zone can be forced to move outward where Jupiter and Saturn are.

[Image by Samihahplanet via https://samihahplanet.wordpress.com/2016/03/16/sun-where-do-you-see-yourself-in-5-billion-years/]

 

After the Sun’s death

[Image by NASA via https://nasa.tumblr.com/post/629433026526494720/the-lives-times-and-deaths-of-stars]

When the Sun finally exhausts all the hydrogens, it will collapse into a white dwarf and form planetary nebula at the outer layer. The Sun will trigger a massive explosion before forming into a white dwarf. However, the explosion will not be big enough to cause a supernova or black hole due to the Sun’s mass. Its size must be ten times greater to cause a supernova and twenty times greater to cause a black hole. Even if the Earth is still alive, the shockwave from the explosion would be strong enough to destroy a huge portion of the Earth. This white dwarf will have 200,000 times higher density than the Earth. It is extremely dense that scientists believe “a mere teaspoon of white-dwarf material would weigh about as much as elephant” (Wall para.2). The Sun will remain as a white dwarf for approximately ten billion more years, and it will slowly cool down to become a black dwarf.

 

Conclusion:

In conclusion, no life will survive the death of the sun, and this is inevitable except leaving the Earth to find another habitable planet before it gets swallowed or burned by the Sun. The Earth might be able to survive after the event if there is a miracle that pushes the Earth to another habitable zone before the Sun’s expansion, but a chance of this happening is almost impossible. Unless a miracle happens, the Earth will likely to be swallowed by the Sun or become a dead star.

Works Cited:

Specktor, Brandon. “No Life Will Survive the Death of the Sun – but New Life Could Be Born after, New Research Suggests.” LiveScience, Purch, 21 July 2021, www.livescience.com/solar-wind-destroy-earth-magnetosphere.html.

“The Sun and Nuclear Fusion.” AstroPages | Sun and Fusion | Western Washington University, 2 Mar. 2022, www.wwu.edu/astro101/a101_sun.shtml#:~:text=In%20the%20core%20of%20the,mass%20is%20converted%20into%20energy.

Emspak, Jesse. “What Will Happen to Earth When the Sun Dies?” LiveScience, Purch, 13 Apr. 2016, www.livescience.com/32879-what-happens-to-earth-when-sun-dies.html.

“Our Sun.” NASA, NASA, 15 Oct. 2021, solarsystem.nasa.gov/solar-system/sun/in-depth/.