The rocky planets Mercury, Venus, Earth, and Mars were born at the same time from the same material - yet have lived radically different lives. What immense forces are at play?

In the final episode, Professor Brian Cox journeys to the remotest part of the solar system, a place that the most mysterious planets call home.

Professor Brian Cox reveals the history of Saturn. Saturn began life as a strange planet of rock and ice and in time transformed into a gas giant, ring-less and similar looking to its rival, Jupiter.

Brian Cox continues his exploration of the solar system with a visit to a planet that dwarfs all the others: Jupiter. Its size gives it a great power that it has used to manipulate the other planets.

Professor Brian Cox continues his tour of the solar system revealing that it was once home to not one, but two blue planets.