Every beginning has an end. AND our Solar System, no matter how long ahead it appears on its horizonThere will come a time when everything will end. On Earth we will not see when our massive star becomes a red giant, since long before the world we live in will be uninhabitable.
Scientists have an estimate of when the life of the massive star that we see rising every day in our skies will end. The Sun is approximately 4.5 billion years old. This type of star lasts about 9 billion years, so we would be talking about it currently being halfway through its existence.
Do we have 4.5 billion years of life left on Earth? No, the reality is that there is much less left.
At some point, the size of the Sun multiplied by 1,000, the Earth would be swallowed by it. The effects of the Sun’s increasing size would be felt on Earth long before the star grows to such diameters.
Increasing the Sun’s gravity would cause the Earth to move closer to it, shortening its orbit. Increased solar radiation would cause the planet to warm, thereby causing sea level rise and the extinction of many species.
As the Sun continued to grow, the Earth would get closer and closer to it. Finally, the star would extend until it touched the world until it enveloped us in its flames.
The current life of the Sun
Currently, the Sun is in the main sequence phase, where it fuses hydrogen into helium in its core. In about 5 billion years, it is expected to exhaust its core hydrogen supply and enter an expansion phase, becoming a red giant.
During this phase, the Sun will swell enormously and is expected to engulf the nearest planets, including Earth. However, estimates suggest that even before this occurs, the gradual increase in the Sun’s luminosity will affect conditions on Earth significantly.