We've photographed strange new worlds, stood in unfamiliar landscapes, tasted alien air.The first episode illustrates how the formation and behaviour of the Sun affects each planet in the Solar System.

An explanation of the Earth's exposure to the power of the Sun occurs in Death Valley, California, US, with an experiment inspired by John Herschel's actinometer.

Cox then relates the Voyager missions and their continuing exploration of the massive reach of the Sun's gravitational forces on objects in the farthest regions of the Solar System.

Finally, in the clear skies of the Atacama Desert, at the Paranal Observatory he is able to observe, with the naked eye, the myriad of stars on the Milky Way and relates the meaning of their diverse colours as mapped on the Hertzsprung–Russell diagram.

Cox starts this episode in Al-Qayrawan, Tunisia to analyse the orbit of the planets around the Sun, with details on how the 23-degree tilt of the Earth creates the seasonal weather patterns.

He also visits the Atlas Mountains, and relates how in clear night skies the ancients observed the rotation of the stars and the retrograde and prograde motion of Mars and the other wandering planets.

The episode starts with Cox travelling to South Africa and taking a journey in an English Electric Lightning up to an altitude of 18 kilometres where the "thinness and fragility" of the atmosphere could be observed in the middle of the day.

Later, the dunal morphology of the Namib Desert is compared to what is known of the surface and depleted atmosphere of Mars, and is used to give an explanation of how the Earth maintains its temperature.

The same gravitational force is also shown to give the Jovian moon Io geological life (given the absence of meteor impact evidence there) as paralleled by the volcanism of Erta Ale in Ethiopia.

A trip to the Scablands in North-West America is also made, with an explanation of the Missoula Floods that once occurred there, and how the tell-tale signature of water shaped the landscape geologically.

The exploration of Mars has revealed possible evidence of its subterranean hydrology, and a visit to the Cueva de Villa Luz in Mexico shows how simple life-forms (such as archaea and snottites) survive in hostile conditions beneath the Earth.

Conversely, the hostile frozen topography of Jupiter's moon Europa also reveals the presence and effects of sub-surface water, and Cox visits a cave in Vatnajökull to find microbial signs of life beneath the ice.