How Does Fusion Power the Sun? The Sun contains 99.8 percent of all matter in the solar system. Under crushing pressure and extreme temperatures generated by gravity, the violent process of nuclear fusion powers the tremendous energy output of the sun. Facebook Prev Article Next Article Discover Checkout these cool gadgets... Related Posts Can Science Turn Love Into A Pill? Why Does The Moon Look Bigger On The Horizon? Unsolved Mystery? Fuel is cheap. Why are we still paying to check bags? What The Future of Transportation Looks Like Why Is It So Hard to Build an ICBM? How Much Can You Carry?