You would need to detonate a hydrogen bomb every second for the next 3,200 years to equal the Sun s energy output every second. This energy output comes from a process called nuclear fusion, which fuses hydrogen atoms into helium atoms. Dwarf stars come in many different colors. Our Sun is a yellow dwarf, laying in the middle zone between cooler, redder stars and hotter, bluer stars. Planetary scientists generally define the livable region around the Sun as the distance at which liquid water can exist on a planet s surface for long periods of time.
Liquid water is essential for biological systems for many reasons.
Among them is the fact that water can hold a lot of heat. Water can also dissolve and hold an abundance of different chemicals, providing the medium for all sorts of biogenic reactions. Had it not been for this last feature, Earth would have formed into a solid ice cube. Instead, when the bottom of the ocean got cold enough to produce ice, the ice broke off, floated to the surface, and was melted by the Sun s heat. The Sun is also getting brighter.