* Expansion and Heating: As the Sun runs out of hydrogen fuel in its core, it will begin to fuse helium into heavier elements. This process causes the Sun to expand dramatically, becoming a red giant. The Sun will grow so large that it will engulf Mercury, Venus, and potentially even Earth.
* Increased Energy Output: The Sun's surface temperature will also increase during this phase. While the Sun's overall luminosity will decrease, the Earth will be much closer to the Sun, leading to significantly higher temperatures.
* Uninhabitable Conditions: The increased heat and radiation will make Earth's surface uninhabitable for any known life forms. Oceans will boil away, and the atmosphere will be stripped away.
Timeline:
This event is still billions of years away. The Sun is currently in its main sequence phase, which is expected to last for another 5 billion years. After that, it will transition into the red giant phase, which will last for another billion years or so.
It's important to note that while the exact details of the Sun's evolution and its impact on Earth are still being studied, the basic principles of stellar evolution suggest that this scenario is highly likely.
