How Long Will The Sun Last?

Written by Dayva Segal
Updated: August 2, 2022
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To someone on another planet outside of the solar system, our sun might just look like any other star. But to those of us living on Earth, it is the source of all life! Without the sun we would have no plants to eat or to make the atmosphere breathable for humans and all of Earth’s other animals. It also heats the planet to a reasonable temperature (in most places) so that life as we know it can exist.

Today, solar energy from the sun is a viable renewable energy source. Even on a cloudy day, solar panels can collect at least some solar energy to power electronic devices, buildings, and now, electric cars.

Due to its physical importance, the sun is also an important figure in many religions. Some religions, both ancient and current, view the sun as a Deity. For example, in Hinduism, the sun is a god called Surya Dev. Other religions placed monuments to the sun that are still around today, like Stonehenge. In many religions, the quality of light is associated with purity or piousness, and darkness is associated with evil. Some believe that is due to the life-giving qualities of sunlight.

The sun is extremely important to our existence, so the thought of it going away might sound scary. But, the sun is a star like any other. Someday, it will die. But when will that happen?

how long will the sun last?
The stars of a planet and galaxy in space. Our sun is also a star and will die someday.

©Zakharchuk/Shutterstock.com

When Will the Sun Die?

The sun will officially die in about 7-8 billion years from now. However, it will fundamentally change before then. To learn more about this, we must first explore more details about our sun.

How Long Has the Sun Been Around?

The sun formed about 4.6 billion years ago. Scientists believe it was made during the gravitational collapse of matter in this area of space.

What Type of Star Is Our Sun?

Our sun is a yellow dwarf star. A more scientific name for this type of star is a G-type main-sequence star or G star. The name yellow dwarf star isn’t exactly correct. These stars are actually white or only slightly yellow. However, when we see the sun through our atmosphere, it has a yellowish tint.

This type of star is fueled by hydrogen. Its core works to turn hydrogen into helium using nuclear fusion, a process of combining two or more atom nuclei or subatomic particles. The differing mass between the combining particles results either in the release of some energy, or the absorption of some energy. In a yellow dwarf star, the energy is released as helium—but only as long as the star has enough hydrogen to fuel it.

What Will Happen When the Hydrogen Runs Out of Our Sun?

When a yellow dwarf star runs out of hydrogen, which takes about 10 billion years, it will first expand, darken, and cool. During this phase, it will become a subgiant star.

When this happens, first, the Earth will get way hotter. It will be hot enough to remove the planet’s atmosphere and evaporate all of the oceans. The atmosphere will become loaded with carbon dioxide.

After about 1 billion years of expansion, darkening, and cooling, the sun will become a red giant. This is a huge type of star that has a low mass, meaning it is pretty spread out.

When it is in this phase, it will likely be large enough to envelop both Mercury and Venus, and may or may not envelop the Earth depending on how large it gets. Any planet it envelops will probably disintegrate. Even if it does not envelop the earth, it will be close enough to vaporize pretty much everything on Earth except for the iron core of the planet.

The extra radiation from the sun will also affect the other planets, which have all developed and adapted to their relatively static distances from the sun.

In the first few million years as a red giant, the sun will expand and contract, which may affect its gravitational pull. This could affect the orbit of the remaining planets in our solar system, either drawing them into the sun or flinging them out to travel in space.

The next few hundred million years will see some of the outer objects, like Pluto, turning into potentially habitable areas for humans. The extra reach of the sun will melt the water on their icy surfaces. However, at the end of the red dwarf phase, the sun will become a white dwarf, a small, hot, and dense star that sends out unimaginable levels of heat and radiation. After another billion years, the star will have cooled to more reasonable temperatures and could support life very close by, even closer than Mercury is to the sun today. However, it might need to be so close that the white dwarf’s gravitational pull would make life challenging.

One planet has ever been discovered orbiting a white dwarf star, so it is possible. Luckily, this is all billions of years into the future. By the time our sun runs out of hydrogen, many experts believe that humans will be long gone. To put it plainly, they believe we’ve got more pressing issues to worry about.

So, How Will Humanity End?

how long will the sun last?
Students of diverse cultures celebrate together. Humanity as we know it will probably die out long before the sun does.

©DisobeyArt/Shutterstock.com

If experts believe that we don’t need to worry about the sun dying during humanity’s time on Earth, what issues are they more concerned about?

In most countries, the human birth rate is already below the death rate. While we are still on the rise in terms of population numbers, experts believe that humanity’s population will start to level off around the year 2100 before going down.

Some scientists believe that a lowering of sperm quality due to environmental factors like pollution and stress will eventually lead to very low birth rates. They also believe that economics is another factor causing a lower birth rate.

Other experts have been calculating probabilities of what will end humans and when. Some believe there is a 19% chance that humanity as we know it will end before the year 2100. They say there is a 5% chance of some catastrophe caused by new molecular weapons or incredibly smart artificial intelligence. Other experts believe there is a 30% chance that humanity will die out in the next 500 years. Others say that climate disasters will end civilization as we know it in as little as 20 to 40 years!

However, it’s important to remember that for thousands of years, if not more, humans have been wondering about (and planning for) the end. Many philosophers and religious leaders have even gone so far as to pin down a date and tell everyone to get ready for the apocalypse. (Did anyone else have an “apocalypse party” on December 21, 2012?) Even going as far back as the year 365, Hilary of Poitiers said the earth wouldn’t last beyond that year.

The only one of these “apocalypses” we can be certain of is Earth’s date to get closer to the sun as it dies and expands several billion years from now.

Learn More…

Read these articles to learn more about our place in the universe and solar system:


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how long will the sun last?
A wide view of the sun and stars from space.
© Triff/Shutterstock.com

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About the Author

I'm a freelance writer who has been working in the field of content creation and digital marketing for more than seven years. My favorite topics to write about include health, animals, fitness, and nutrition, though as a professional content provider and ghostwriter, I can easily write about pretty much anything! I love all animals and have been some form of vegetarian or vegan for over 10 years. My favorite animals are cats, dogs, and chickens, especially my own cat, Tula.

FAQs (Frequently Asked Questions) 

How Long Will The Sun Last?

The sun will officially die in about 7-8 billion years from now. However, it will fundamentally change before then. To learn more about this, we must first explore more details about our sun.

How Long Has the Sun Been Around?

The sun formed about 4.6 billion years ago. Scientists believe it was made during the gravitational collapse of matter in this area of space.

What Will Happen When the Hydrogen Runs Out of Our Sun?

When a yellow dwarf star runs out of hydrogen, which takes about 10 billion years, it will first expand, darken, and cool. During this phase, it will become a subgiant star.

When this happens, first, the Earth will get way hotter. It will be hot enough to remove the planet’s atmosphere and evaporate all of the oceans. The atmosphere will become loaded with carbon dioxide.

After about 1 billion years of expansion, darkening, and cooling, the sun will become a red giant. This is a huge type of star that has a low mass, meaning it is pretty spread out.

When it is in this phase, it will likely be large enough to envelop both Mercury and Venus, and may or may not envelop the Earth depending on how large it gets. Any planet it envelops will probably disintegrate. Even if it does not envelop the earth, it will be close enough to vaporize pretty much everything on Earth except for the iron core of the planet.

The extra radiation from the sun will also affect the other planets, which have all developed and adapted to their relatively static distances from the sun.

In the first few million years as a red giant, the sun will expand and contract, which may affect its gravitational pull. This could affect the orbit of the remaining planets in our solar system, either drawing them into the sun or flinging them out to travel in space.

The next few hundred million years will see some of the outer objects, like Pluto turning into potentially habitable areas for humans. The extra reach of the sun will melt water on their icy surfaces. However, at the end of the red dwarf phase, the sun will become a white dwarf, a small, hot, and dense star that sends out unimaginable levels of heat and radiation. After another billion years, the star will have cooled to more reasonable temperatures and could support life very close by, even closer than Mercury is to the sun today. However, it might need to be so close that the white dwarf’s gravitational pull would make life challenging.

One planet has ever been discovered orbiting a white dwarf star, so it is possible. Luckily, this is all billions of years into the future. By the time our sun runs out of hydrogen, many experts believe that humans will be long gone. To put it plainly, they believe we’ve got more pressing issues to worry about.

How Will Humanity End?

In most countries, the human birth rate is already below the death rate. While we are still on the rise in terms of population numbers, experts believe that humanity’s population will start to level off around the year 2100 before going down.

Some scientists believe that a lowering of sperm quality due to environmental factors like pollution and stress will eventually lead to very low birth rates. They also believe that economics is another factor causing a lower birth rate.

Other experts have been calculating probabilities of what will end humans and when. Some believe there is a 19% chance that humanity as we know it will end before the year 2100. They say there is a 5% chance of some catastrophe caused by new molecular weapons or incredibly smart artificial intelligence. Other experts believe there is a 30% chance that humanity will die out in the next 500 years. Others say that climate disasters will end civilization as we know it in as little as 20 to 40 years!

However, it’s important to remember that for thousands of years, if not more, humans have been wondering about (and planning for) the end. Many philosophers and religious leaders have even gone so far as to pin down a date and tell everyone to get ready for the apocalypse. (Did anyone else have an “apocalypse party” on December 21, 2012?) Even going as far back as the year 365, Hilary of Poitiers said the earth wouldn’t last beyond that year.

The only one of these “apocalypses” we can be certain of is Earth’s date to get closer to the sun as it dies and expands several billion years from now.

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