Science

In this episode, Helen seeks out the colours that turned planet Earth multicoloured. To investigate the essence of sunlight Helen travels to California to visit the largest solar telescope in the world. She discovers how the most vivid blue is formed from sulfur atoms deep within the Earth's crust and why the presence of red ochre is a key sign of life. In gold, she discovers why this most precious of metals shouldn't even exist on the surface of the planet and in white, Helen travels to one of the hottest places on Earth to explore the role salt and water played in shaping planet Earth.

An exploration of Earth's cosmic neighbourhood. Looking beyond the borders of our solar system, what's nearby in our galaxy? How do the other objects in our local area influence life on Earth? And, how did Earth's place in the galaxy make it the perfect place for the development of advanced life? Now that the Voyagers have visited the outer planets of the solar system they are heading for new adventures in places astronomers call the Oort Cloud, the heliopause, heliosheath and eventually they may encounter double stars and exoplanets, some of which may pay a visit to the solar system one day or explode showering us with radiation. If the Voyagers live so long they will experience the local fluff, local bubble and other parts of the habitable zone of the galaxy.

The film looks at the latest understanding of black holes, featuring an interview with Stephen Hawking. Black holes are one of the greatest mysteries in the universe. They behave in a way that is contrary to laws of physics and one has never actually been seen. However, the recent detection of gravitational waves, as predicted by Einstein, proves that black holes exist and provides a way to investigate their remarkable behaviour and properties.

The Internet is an uncontrollable labyrinth of content and imagery that operates under loose laws and partial anonymity - a new frontier where people can do anything and see anything, whether they should or not. In this lawless landscape, who's in control? The protectors? The abusers? In this episode meet the content moderators who watch the worst of the Internet so you don't have to; a convicted hacker whose punishment was the virtual prison of the unplugged; plus, a blackhat hacker who encrypts and holds computer files hostage.

The human eye can see extraordinary detail, but the eye of a needle held at arm's length is pretty much at the limit of our vision. Anything smaller is simply invisible, at least to the naked eye. But what if we could see this hidden world all around us in greater detail and magnification than ever before? How different would our familiar surroundings then seem? Richard Hammond explores the astonishing miniature universe all around us, revealing that small is not only beautiful, it can also be very, very powerful. From seeing the microscopic changes to ice crystals that can trigger an avalanche to watching in horror the invisible aftermath of a sneeze on a commuter train and learning how the surface of an ordinary-looking plant hides an astounding secret that will make walking on the moon safer, Richard harnesses cutting-edge technologies to transport the viewer into a spectacular micro realm.

Chris Lintott and Maggie Aderin-Pocock report on the reaction to the dramatic announcement of the discovery of phosphine gas in the clouds of Venus, a gas that could be a sign of life. Venus remains an inhospitable and unlikely host. But if not Venus, where in the solar system is the best place to look for alien life? Chris and Maggie investigate the latest missions to Mars and the icy moons of Jupiter and Saturn. Away from the search for life, Pete Lawrencepreviews the best meteor showers of the year.