The Origin of
the Solar System
Five billion years ago a cloud of hot swirling dust and hydrogen
gas gave birth to our Sun and planets. As the cloud spun and collapsed
inwards it flattened into a central mass with a surrounding disk.
Dust and gases in the disk formed small condensations each spinning
about its own centre. Gravitation condensed and heated the central
mass. Density increased dramatically and [nuclear] fusion began.
Energy was released and our Sun flared into existence. The solar
wind of the newly ignited Sun blew away leftover dust and gas in
the vicinity of the inner condensations, leaving the rocky inner
planets: Mercury, Venus, Earth and Mars. In the outer regions of
the disk, the solar wind was weaker. The remaining dust and gas
condensed into the larger gaseous planets: Jupiter, Saturn, Uranus