Drama-documentary telling the gripping story of an encounter with an alien object travelling through the solar system.

All the incredible diversity of animal life sprang from a single organism. Every animal, no matter how weird, is related to every other. And behind each species is an incredible story of the millions of generations that gave rise to it - every animal we know and love today sprang from creatures that looked nothing like it.

In this spellbinding series, Professor Brian Cox visits the most extreme locations on Earth to explain how the laws of physics carved natural wonders across the solar system.