Earth is under constant threat from asteroids and comets that could destroy the planet. Dr Kaku finds out how a rogue star could be detected, assessed and eliminated.

Dr Michio Kaku draws up ambitious plans for the construction of a new solar system. Details involve a giant shell encircling a star, with a new stellar civilisation living on the inside.

The aliens are coming! It is the cry at the heart of many sci-fi movies, but what would we do if an alien race really did invade? Earth must be prepared - and Dr Kaku has a plan.