The inner Solar System is the region comprising the terrestrial planets and the asteroid belt.[66] Composed mainly of silicates and metals, the objects of the inner Solar System are relatively close to the Sun; the radius of this entire region is less than the distance between the orbits of Jupiter and Saturn. This region is also within the frost line, which is a little less than 5 AU (about 700 million km) from the Sun.[1]


  1. "Frost line or snow line or ice line in the solar system". Astronoo. Retrieved 28 November 2017