Just how much time do we have until the sun goes out?

All good things must come to an end, and, unfortunately for us, that includes the sun. But just how much time do we have until the light goes out?

The sun is about 4.6 billion years old and it will burn for another five billion years. That means we are about halfway through its adult phase.

But sadly, our time on earth will come to an end way before those five billion years run out. Every one billion years, the sun gets 10 percent brighter — and hotter.

This increase might seem small, but its impact on our planet is massive. The earth sits just inside of the sun’s habitable zone, or "Goldilocks zone" — where it's not too hot, and not too cold, it's just right.

In this zone, a planet can hold liquid water, the key ingredient to sustaining life. It is estimated that in almost two billion years, the growing sun's heat will push us out of that zone. At this point, all water on the Earth's surface, all oceans, rivers, and lakes will evaporate.

Toxic gases previously locked away in frozen ground will then escape into the atmosphere. Eventually, all life on our planet will disappear.

But, if we do somehow manage to escape this fate, and survive billions of years into the future, we could witness the sun's fiery finale — which will be quite a spectacle to behold.

To find out more, check out the above episode of "Space, Down to Earth!"

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