The Greeks named the sun Helios, but the Romans used the name Sol, which is still in use today. Due to the important role the sun plays in our lives, it has been studied, perhaps, more than any other object in the universe, outside our own planet Earth.
The Sun is the closest star to Earth. It is by far the largest object in the solar system, and contains more than 99.8% of the total mass of the Solar System (Jupiter contains most of the rest). Its strong gravitational pull holds Earth and the other planets in the solar system in orbit.
Our Sun is considered to be an average star, meaning its size, age, and temperature fall in about the middle of the ranges of these properties for all stars. It is only 4.6 billion years old. Some of its material came from former stars.
The four planets nearest it are rocky, terrestrial worlds — Mercury, Venus, Earth and Mars. After that are four gas giants — Jupiter, Saturn, Uranus and Neptune. Between the orbits of Mars and Jupiter lies the asteroid belt, which includes the dwarf planet Ceres. Beyond the orbit of Neptune one finds the disk-shaped Kuiper belt, in which dwarf planet Pluto resides, and far beyond that is the giant, spherical Oort Cloud and the teardrop-shaped heliopause.