AUDIO:
The solar system formed from an immense rotating cloud of gas and dust, the
solar nebula. The sun's nuclear fires ignited at the dense center of this 
nebula. The planets were born in the swirling currents of the great cloud.
Planets near the sun, Mercury, Venus, Earth, and Mars, evolved as globes of
rock. They were too small and their gravitational fields too weak to capture
and hold the gases from the nebula. But far from the sun, the massive planets
Jupiter and Saturn, with powerful gravitational fields, did attract and hold
thick gaseous atmospheres of Hydrogen and Helium.

VIDEO DESCRIPTION:
Animation of swirling cloud in space. Sun being born. Planets being born. 
Cratered surface of rocky planet. Zoom out from central solar system to
see the outer gaseous planets in their orbits.