The Sun is so heavy that it makes up 99.86% of the entire solar system's mass.

The Sun weighs about 333,000 times more than Earth. Most of the tiny bit of mass left over is found in Jupiter, which is bigger than all the other planets put together. This lopsided balance started 4.6 billion years ago when a giant cloud of gas and dust collapsed. Almost all that material pulled into the center to create the Sun, leaving only tiny scraps to form the planets.The Sun is mostly made of hydrogen and helium gas. In its center, the weight of all that gas creates a crushing pressure and a temperature of 15 million degrees Celsius. This heat is so intense that it triggers nuclear fusion, which is how the Sun creates light and energy. Without this incredible amount of mass, the Sun would never have turned into a star.To imagine the scale, if the Sun were as tall as a typical front door, Earth would be the size of a small coin like a nickel. NASA scientists use satellites like the Solar and Heliospheric Observatory to study how this massive weight affects the orbits of the planets. Even though the Sun is 93 million miles away, its huge mass keeps Earth exactly where it needs to be.