The new discovery of seven alien Earth-like planets in a faraway solar system is a major milestone in our hunt for extraterrestrial life, and experts investigate the secrets of TRAPPIST-1's mysterious worlds to reveal if we're truly alone in the universe.
Neutron stars are strange and violent phenomena that defy the laws of physics, and new discoveries reveal that these bizarre nightmares are far more deadly than previously believed, with the power to destroy planets and even other stars.
Scientists and modern explorers are determined to send humans to Mars; as NASA builds its first spacecraft to carry astronauts to Mars and tech visionaries devise extraterrestrial colonies, future on Mars might be a reality.
Kevin explores life in orbit on board the Station. As Tim settles in to his new home he sends special reports about what it takes to live and work in space. Four hundred kilometres above the Earth, hurtling at a speed of 17,500mph, astronauts' bones and muscles waste away, the oxygen they breathe is artificially made, and they face constant threats from micrometeorites, radiation and extreme temperatures. If a medical emergency strikes, Tim is a very long way from home. In its 15-year lifetime, the International Space Station has never had a major accident. With a British astronaut in orbit, gravity-defying experiments and guest astronauts in the lecture theatre, Dr Fong shows us how to survive life in orbit.
In 2014, the International Space Station had to move three times to avoid lethal chunks of space debris and there is an increasing problem of satellites mysteriously breaking down. With first-hand accounts from astronauts and experts, Horizon reveals the scale of the problem of space junk. Our planet is surrounded by hundreds of millions of pieces of junk moving at 17,000 miles per hour. Now the US government is investing a billion dollars to track them, and companies around the world are developing ways to clear up their mess - from robot arms to nets and harpoons. Horizon investigates the science behind the hit film Gravity and discovers the reality is far more worrying than the Hollywood fiction.
In summer 1969, Apollo 11 succeeded as the first manned mission to land on the moon. The next challenge was to design and build the first exploration vehicle. It had to allow astronauts to explore the moon's surface, but it had to fit in just a meter square space!