Solarsystem

The Sun is by far the largest object in the solar system. It is the star at the center of the Solar System. The Earth and other matter (including other planets, asteroids, meteoroids, comets and dust) orbit the Sun. Energy from the Sun (sunlight) supports almost all life on Earth via photosynthesis, and drives the Earth's climate and weather.

The Sun contains more than 99.8% of the total mass of the Solar System (Jupiter contains most of the rest). At present, the mass of the Sun is about 70% hydrogen, 28% helium by mass, other metals amount to less than 2%. This changes slowly over time as the Sun converts hydrogen to helium in its core.

The Sun's energy output (
3.86e33 ergs/second or 386 billion billion megawatts) is produced by nuclear fusion reactions. As it travels out toward the surface, the energy is continuously absorbed and re-emitted at lower and lower temperatures so that by the time it reaches the surface, it is primarily visible light.