It's only a maybe that Earth will get eaten when the sun goes red giant. There are models that indicate that the suns expansion may affect the orbit sufficiently to push us out to about where Mars is now, sparing it getting eaten, but not doing us a bit of good.
The bigger worry for life here is that the sun will continue to get hotter throughout it's normal life cycle, meaning that within about a billion years it will be too hot here to sustain surface water any more as there will be enough energy in the atmosphere to shoot water particles out to space at a high enough rate to dry the whole planet.
Nothing like this particular stellar event will happen here. This planet, WASP 12B, is orbiting its sun (which is close in size to ours) every one of our days, practically skipping across the star's face, at 130 miles per second, making the planet at least as hot as four thousand degrees Fahrenheit. It's almost twice as big as Jupiter, superexpanded from all that heat, and the star is tearing it apart at that short distance. Its sun hasn't reached the end of its main sequence yet to become a red giant, when it will instantly engulf and probably absorb most of what remains of WASP 12B. Pretty much nothing about this strange, superhot, unstable gas giant is anything like our world.
- Now and Then, Here and There
The bigger worry for life here is that the sun will continue to get hotter throughout it's normal life cycle, meaning that within about a billion years it will be too hot here to sustain surface water any more as there will be enough energy in the atmosphere to shoot water particles out to space at a high enough rate to dry the whole planet.
That's it: I'm spending my savings. Carpe diem.