Have no fear, the sun will not explode. You need about 8 times the mass of the sun in order for a star to explode in a supernova. The sun will expand into a red giant when it finishes fusing hydrogen into helium. When this happens the earth might be swallowed up in the expansion. After the sun finishes burning helium and continues up the fusion chain to iron the fusion in the core will fail and the outer layers of the sun will puff off into a planetary nebula. This won’t be a particularly violent event. The naked core leftover will be a white dwarf which is effectively just a molten ball of mostly carbon and oxygen gradually cooling off. It will take trillions of years to cool off.
Although, it’s just a couple of hundreds of thousands millions of years before the sun expansion brightness makes Earth inhabitable. Not to make anyone freak out, but that’s about 10 times less than 5 billions! Enjoy your life while you can!
Edit: sorry for writing mistakes at 2 am, see various sources below.
No, the expansion will start in about 5 billion years. The subgiant expansion phase will last for about 1 billion years. The earth may or may not be engulfed during the expansion as the best guess is the sun will expand to somewhere between venus and earth’s orbit. The planet will be uninhabitable but again, the expansion won’t start for about 5 billion years.
You’re the second person in as many days that I’ve come across saying the red giant expansion phase will start in 500 million years. Where are you guys getting this info?
I may have confused expansion with brightness, it is increasing steadily and will make our planet inhabitable in that time frame. From astrophysist Paul M. Sutter https://www.space.com/solar-system-fate-when-sun-dies
It’s a few hundred million years, not a few hundred thousand, before the photosynthetic cycle is disrupted by silicate weathering from increased brightness.
Oh, I thought I had written millions as in my source instead of thousands, I shouldn’t write comments at 2 am, two mistakes. I didn’t know about the silicate issue but the estimated remain consistant with my initial source.