Solar System

The Origin of the Solar System

The Solar Nebula Theory

States that our solar system was probably formed out of a spinning ball of gas. Around 4.5 billion years ago, the sun came into being and the remaining dust and gases were blown out into space. The planets began to revolve around the sun in orbits that nearly fell into a common plane amongst all the planets and all revolved around the sun in a counter-clockwise fashion. During the process of condensation, the heavier elements were condensed toward the hotter, inner part of the nebula, while the lighter, more volatile elements condensed further out. This process has, therefore, created two types of planets: the Terrestrial (Earth-like) and Jovian (Jupiter-like) planets. The Terrestrial planets include: Mercury, Venus, Earth, and Mars; which all share the common characteristics of being small, dense, and rocky. The Jovian planets include: Jupiter, Saturn, Uranus, and Neptune; all are characterized by being enormous gas giants and are larger, less dense, and much cooler than the Terrestrial planets. When the nebula started to cool off, smaller forms of material began to collect mass, which are referred to as planetisimals. The inner planetisimals accrued heavier material through the process of condensation and the lighter material was swept away by solar wind. The planetisimals that skirted further out from the solar system accrued lighter material. As these types of planetisimals began to gain mass, they began to act as vacuum cleaners that filtered the void of debris that later formed and became the planets. The solar system is still littered with three types of debris left over from the birth of the solar nebula, which are known as asteroids, comets, and meteoroids.

Mercury    Venus    Earth   Mars    Jupiter    Saturn    Uranus    Neptune    Pluto    The Sun   The Moon    Space Objects    Black Holes   Dark Matter     Galaxies    Nebulae    Pulsars   Quasars    Stars    Star Clusters