We all know the Sun will evolve into a bloated, overluminous giant about 5 billion years from now - a timeframe that depends on the amount of heavy elements in the Core. According to a fairly standard model, the Sun’s future is as follows (in gigayears of the Sun’s age. Subtract 4.6 Gyr to get the date from now)…<br /><br />(A) Core burning ends, t = 9.4 Gyr<br />(B) Redwards Traverse, end of Main Sequence, t = 10.9 Gyr (Sun pretty stable, Mars’ temperature rather nice)<br />(C) First RedGiant ascent, t = 11.6 Gyr (Sun goes from about 3 times present luminosity to about 2,400)<br />(D) Sun’s Core explodes, Helium burning begins, t = 12.1 Gyr (Sun pretty stable, Jupiter’s rather nice)<br />(E) Asymptotic Giant Branch, t = 12.2 Gyr (Sun goes from about 45 to 6,000 times present)<br />(F) Planetary Nebulae shed off, Sun dies as White Dwarf, t = 12.25 Gyr<br /><br /><br />Instead of migrating, moving the Earth, or moving into space permanently - and they’re all options that might be taken - I would suggest a more radical option: engineer the Sun.<br /><br />A few facts suggest this might be worthwhile.<br /><br />First, the Sun will go red giant after using a tiny fraction of its total energy potential. This seems rather wasteful to me.<br /><br />Second, magnetic fields can potentially reach all the way down into the Sun’s core. Thus we might be able to control the Sun’s energy output and its chemical evolution by inducing convection.<br /><br />So just how much energy is available? If all the Sun’s mass converted to energy at current output it would last 14.5 trillion years. But it’s a giant fusion reactor instead. Proton-proton fusion, and associated reactions, convert 0.685% of the mass into energy. As the Sun is currently 74% hydrogen, proton-proton fusion would last 74.6 billion years using all the hydrogen. If we ignited helium fusion after that we might get another 15 billion years.<br /><br />That sounds pretty good, but could we go further?<br /><br />Some of