S04 Episode 1
Glacier Meltdown
Wed, 31 Jan 2007
S04 Episode 2
Destructive Forces
Wed, 21 Feb 2007
S04 Episode 3
Stone Age Apocalypse
Wed, 28 Feb 2007
S04 Episode 4
Comets
Wed, 7 Mar 2007
S04 Episode 5
Prehistoric Americans
Wed, 14 Mar 2007
S04 Episode 6
Deep Space Probes
Tue, 27 Mar 2007
S04 Episode 7
Dino Meteor
Thu, 12 Apr 2007
S04 Episode 8
Planet Storm
Thu, 26 Apr 2007
S04 Episode 9
Polar Apocalypse
Sun, 1 Apr 2007
S04 Episode 10
Killer Lakes
Thu, 3 May 2007
S04 Episode 11
Ring of Fire
Thu, 2 Aug 2007
S04 Episode 12
Alien Safari
Thu, 9 Aug 2007
S04 Episode 13
Hyper Hurricanes
Thu, 18 Oct 2007
S04 Episode 14
Dangers of the Deep
Thu, 25 Oct 2007
S04 Episode 15
Solar Force
Tue, 30 Oct 2007
S04 Episode 16
Birth of the Solar System
Tue, 6 Nov 2007
S04 Episode 17
Hubble Trouble
Tue, 6 Nov 2007