Solar system bodies and "primitiveness"

Abstract

Planets and small bodies. Besides the Sun, which represents about 99.85% of its mass, the present day solar system include large bodies, i.e., the four terrestrial planets, the four giant planets, and Pluto, which is probably not a planet, but rather an object from the Edgeworth-Kuiper belt of comets captured by Neptune; more than 130 satellites of the planets. Jupiter, the most massive planet of the solar system, is about 320 times more massive than the Earth, which weighs about 80 lunar masses. Its orbit separates the two very distinct worlds of the inner solar system, populated by rocky bodies, from the outer solar system, which is the world of the giant gaseous planets, icy bodies and intense coldness, which starts at around 5 astronomical units (AU) from the Sun and ends up at 50,000 AU with the outer edge of the Oort cloud of comets -one AU is the average distance between the Earth and the Sun, of about 150 millions of km. © Springer 2006.