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Will the Sun ever burn out?

When the Sun has fused all of the hydrogen atoms into helium atoms it will be finished. It would then start to cool and expand. Unfortunately we think it would expand out beyond Earth's orbit. We would be cooked. This is not expected to happen for billions of years. It is hard to think that humans will still be around. We will have left or may not have survived. Nothing to worry about for the next several million years.

Yes. Sun converts Hydrogen into Helium and by radiating this energy it maintains its stability. When the hydrogen content goes down and there is not any left to be converted, it will cool down and end its life. This will happen after a few billion years.

Jasjeet S Bagla

Probably not - the Sun is too small to blow up. However, when the Sun gets really old (about 5 billion years in the future?) it will expand outward and probably grow so big that the Earth will be within the Sun's atmosphere, probably destroying the planet.

A Smith

It is true that when the Sun runs out of its current fuel, hydrogen and starts to cool down, it will expand into a red giant and could expand out to Jupiter. These are the estimates I have seen quoted before. The end of the Sun is billions of years away.

Samuel P Bowen

Yup. About 5 billion years from now, according to our best theories of the way stars get older. The first thing it will do is expand the outer surface of the star, probably too close to the Earth's orbit, which will be pretty much the end of things here.

A Smith

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