"Life will have fried, oceans will have boiled away, but no one has ever been sure what will happen to Earth itself when the Sun finally swells into a red giant. Now, astrophysicists from Mexico and the UK are forecasting a dismal fate for our rocky planet: it will get caught up in the Sun’s outer layers, spiral inwards and vaporize.
Like all dwarf stars, the Sun converts hydrogen nuclei into helium nuclei by fusion to produce immense amounts of radiation and outward pressure. But in five billion years or so the core will run out of hydrogen fuel, lose pressure and collapse under its own gravity. As this inward crush boosts the temperature of the core, the remaining shell of hydrogen around it will heat up and trigger a new period of fusion, which in turn will cause the Sun’s outer envelope to expand to around 250 times its current radius and cool from white to red.
Once the Sun is in this red-giant phase, Mercury will certainly be engulfed, and going on the increase of the Sun’s radius alone it would appear that Venus, Earth and Mars will suffer the same fate too."
One of my biggest interests is thinking about deep time, from earth's origins to its end.