For fusion to occur automatically under its own gravity, a minimum mass of approximately 0.08 solar masses is required for proton-proton chain fusion, while deuterium fusion can occur in objects as small as 13 Jupiter masses. Fusion reactors will likely utilize deuterium due to its higher availability compared to hydrogen, which is found in low concentrations in seawater. The proton-boron reaction is considered a promising candidate for the first commercially viable fusion reactor, as both elements are abundant and accessible. Red dwarfs can sustain fusion for hundreds of billions to trillions of years due to their slow burning rate. The discussion emphasizes the feasibility of fusion energy and the long-term potential of available fuel sources.
