Get flash to fully experience Pearltrees
The Sun is the star at the center of the Solar System . It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields . [ 12 ] [ 13 ] It has a diameter of about 1,392,684 km, [ 5 ] about 109 times that of Earth , and its mass (about 2 × 10 30 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System. [ 14 ] Chemically, about three quarters of the Sun's mass consists of hydrogen , while the rest is mostly helium . The remainder (1.69%, which nonetheless equals 5,628 times the mass of Earth) consists of heavier elements, including oxygen , carbon , neon and iron , among others. [ 15 ] The Sun formed about 4.6 billion years ago from the gravitational collapse of a region within a large molecular cloud . Most of the matter gathered in the center, while the rest flattened into an orbiting disk that would become the Solar System .