They soar through the heavens, fly through the oceans and glide along land. But these are not creatures found on a wildlife safari. These are life forms from another planet. Armed with scientific fact and a little imagination, experts come together to take you on an unprecedented journey to the edges of our imagination.

Right now cosmic forces prowl the universe and threaten man's very existence. They're asteroids and comets; they've left their imprint on planet Earth, literally. Initially helping to build planets through violent collisions, during this fiery bombardment period they may have even seeded Earth with water and the building blocks for life. Since the turbulent formation of the solar system, these space rocks have continued to impact Earth. Some have been so violent that they've led to mass extinctions, including one that wiped out the dinosaur. New theories suggest that asteroid and comet dust harbour deadly viruses that may have triggered some of our worst pandemics. The possibility of future collisions remains a legitimate threat yet despite their dangers, asteroids and comets may hold vital natural resources, which could actually preserve

When mankind eventually leaves the cradle of Earth and ventures forth into the uncharted territories of the cosmos, where, and what form, will our new homes take?

It sounds like a Hollywood blockbuster: a deadly asteroid is on a collision course with Earth. But in reality, it's only a matter of time before a giant space rock threatens to wipe out civilization. An asteroid took out the dinosaurs sixty-five million years ago. Are we next? This episode analyzes the threat and explores the many ways--from a nuclear bomb to ingenious new technology--that experts are proposing to stop Armageddon

No planet beats Saturn for jaw-dropping beauty. Saturn is the most photogenic planet in all the solar system. Some of the pictures are to die for. But the postcards only tell part of the story. It really is rolling and seething inside. For ringside action, soar above the planet with its six-sided storms. Even more mystery surrounds the impressive Fountains of Enceladus where the secrets of life might spring from the moons salty geysers. And the samples are coming out in space, there's a big sign there: Free Samples: Take One.

Uranus and Neptune: The 'ice giants'. Strap yourselves in for an incredible voyage to the most remote and intriguing planets of all. There has never been a better time to boldly go where no human has gone before to follow in the footsteps of our robot pioneers and visit the planets of the Solar System. Ever wanted to be an astronaut? Imagine heading into the Ice Zone, the frigid, dark realm beyond the orbit of Saturn. So far from the Sun, you wouldn't expect much to be happening here. From orbit, Uranus appears sedate and calm. But why is the planet on its side? And Neptune: The second blue planet, and the last world in our Solar System. But something is driving its wild winds. And what about its Great Dark Spot? this planet just changes its spots. Leopards don't, but Neptune does.