[MyPasswordSucks]

> Earth is a moon of Sol, is it not?

No. The sun is a star, so it doesn't get to have moons. It has planets. If Jupiter started generating heat from nuclear fusion reactions, we'd call Io a planet right before we boiled to death, and with our dying breath we'd add "and also, it's no longer a moon".

Putting a leash on a cat doesn't make it a dog, and both of those creatures have four legs even if you call the tails of each a leg. A planet revolves around a star, a moon revolves around a planet (revolving around a star). There's further elements which make Ceres and Ed White's lost glove not a planet or a moon, respectively, but planets and moons are distinct and non-overlapping categories.

[ALittleLight]

Why would we be boiling to death in this situation? Jupiter is much further from Earth than the sun is and Jupiter is also much smaller. Heat would increase, but probably not that much.

[jajko]

I would rather expect Earth to not have a stable orbit. Either ripped apart from fluctuating tidal forces, flung away or in one of suns (thus boiling would happen, briefly) or just generally a much more extreme place compared to now.