The sun won't die in 4.5 billion years. It will move on to the helium-fusing stage of a typical main-sequence star, becoming a red giant. Once that stage ends (I don't know how long), there won't be enough mass to initiate CNO fusion, so the gaseous layers will dissipate as a planetary nebula, and the core will remain as a white dwarf. That's essentially when the sun will die, but the former core will continue to radiate heat for billions of years. Get your marshmallows ready
As the density of the sun drops, the planets will move outward, but it's still an open question as to where Earth will end up. The sun could lose anywhere from 25 to 40% of its mass in the transition, which will directly affect where the remaining planets will orbit. Complicating matters is the fact that stars (and gas giant planets, for that matter) don't have a proper surface. We generally take the boundary between the visible (generated or reflected light) and the invisible to be the surface, but our great distance helps maintain that illusion. Red giant stars are so diffuse that the concept of a surface is really quite meaningless. Recent research, though, indicates that tidal interactions will cause Earth to plummet towards the sun's core long before the red giant transition is complete. Mercury and Venus will certainly be toast, in any case
On a sort-of related note, I personally would like to remain around long enough to witness a nearby star going supernova. There hasn't been a good, visible blast since the 17th century
meddle not in the affairs of dragons, for thou art crunchy and delicious when dipped in ketchup
come on. somewhere at the edge of the bell curve is the girl for me -- xkcd #314
why not downgrade plutonium to a dwarf element? |
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