Our sun, like other stars, will die. Stars only shine as long as they have a source of energy, and eventually that gives out.
The sun converts 700 million tons of hydrogen in its core into 695 million tons of helium to create its own energy, but once all the hydrogen in its core has fused, the sun will begin to run out of fuel. When the sun dies, it will not only impact the Earth, but the entire solar system.
The sun was born about 4.6 billion years ago, it is believed the sun is about halfway through its life. In around 5 billion years, nuclear fusion will be impossible inside the sun. The sun will then run out of hydrogen in its core. When that finishes, it will convert the hydrogen in its outer layers.
The sun will still shine but it will begin to collapse under its own gravity. This will release more energy and the sun will eventually swell in size. Astronomers believe that, at this stage, the sun will be almost three hundred times its size.
Mercury and Venus will be swallowed by the sun. Earth will not be swallowed, but the sun’s heat will burn the planet. Earth will no longer be habitable, but much of the outer solar system will become warmer.
Planets that are now covered in ice will melt and liquid water will be present on their surface. If humans are still alive in five billion years, they will need to find a new home on another planet.