Most planets we know of are so hellish, it seems impossible that anything could live. But it's amazing where life can take hold in the Earth. Astrobiologists look for simple single-celled microbes known as extremophiles in places as Danakil Depression, known in Ethiopia as 'The Gateway to Hell.'
In Episode 2, the fictional world is Janus, a planet in such a close orbit than its rotation is locked by the star's gravity and it always shows the same face to its sun. On one side of the planet, it's always daytime, a searing desert. On the other side, it's forever night, a frozen shadowland. Squeezed between the two, a sliver of perpetual twilight. Freezing meltwater flows from the cold side, carving canyons through the landscape. Deep in these canyons lives an extraordinary five-legged creature.

The little known story of our quest to understand the origins of the Moon. Neil Armstrong's "giant leap for mankind" began a scientific journey of discovery that lead to one of the most startling conclusions in the history of astronomy. The Moon was born from Earth.

Space colonization is no longer the fodder of science fiction, it is becoming a reality. Examine the efforts underway to establish a human colony on Mars, including how they plan to grow food, recycle wastewater and introduce greenhouse gases to revive the red planet and make it more habitable for humans. Cutting-edge computer graphics are used to bring the universe down to earth to show what life would be like on Mars, and to imagine what kind of life forms might evolve in alien atmospheres.

Genetic breakthroughs have shed light on how life evolves in real-time. From filling in the missing links to creating a new species, in the last 50 years scientists have solved some of the biggest mysteries of evolution. In this episode, we look at revolutionary discoveries that shook the world and may shape our future.

The white hole is a region of spacetime and that cannot be entered from the outside, although energy-matter, light and information can escape from it. In this sense, it is the reverse of a black hole. Einstein predicted strange cosmic phenomena known as white holes, but scientists have yet to prove they exist.
Today, astronomers race to find the clues that can unlock the secrets of white holes. They investigate the tiny black holes that hide in the most ancient parts of the universe to finally find the smoking gun.

Planets beyond our solar system are known to astronomers as exoplanets. They are at trillions of miles from Earth and yet, it might be possible to detect a faint signature of life in them. From the light of the stars they orbit that passes through the atmosphere of an exoplanet, it is possible to capture the chemical fingerprint of the elements in that atmosphere.
The fictional world Eden is orbiting not one star, but two. The light from its twin stars powers photosynthesis, pumping more oxygen into the atmosphere than in Earth, allowing life to thrive. Grazers are constantly alert to danger, because the canopy is home to predators perfectly evolved to live among the trees. In Episode 3, another topic are fungi and the role they could play on exoplanets. Ecologist Thomas Crowther talks about the role mycelial networks play in the Rothiemurchus forest in Scotland.