Is Our Sun Burning out?
https://usm.maine.edu/planet/sun-getting-hotter-if-so-why-will-earth-eventually-become-too-hot-life As the Sun ages, it slowly grows hotter due to the accumulation of residual energy emitted by these core reactions. Initially, the Sun was only about 70% as luminous as it is today. Consequently, the solar constant, the energy Earth receives from the Sun, would have been correspondingly lower. "The Faint Sun Paradox" was borne out of the realization that, though the Sun was cooler in its infancy, the early Earth still contained liquid water. * Throughout the subsequent billions of years, the Sun's luminosity increased gradually and will continue to increase in the future. Astronomers estimate that the Sun's luminosity will increase about 6% every billion years. This increase might seem slight, but it will render Earth inhospitable to life in about 1.1 billion years. The planet will be to...