NASA's Unexplained Files

Astronauts are evacuated when a mystery object is discovered hurtling towards the ISS. Plus, a secret agent goes undercover to recover missing moon rocks.

Could spaceships really be powered by atomic bombs? Plus, why was Neil Armstrong's transmission feed cut off when he spotted strange lights on the Moon?

Test pilot ace Gordon Cooper is preparing to test a revolutionary landing system when two UFOs appear. Plus, what is the mystery of Saturn's mega-hex?

Apollo 12 astronauts bring back something alive from the moon and NASA track an asteroid heading towards Earth only to make a shocking discovery.

An Apollo 17 photo seems to show a US military outpost on the Moon and is life in the oceans of Jupiter's moons? Plus Neil Armstrong faces real danger.

When a Chinese moon rover breaks down, a NASA scientist points to a mysterious material that seemed to sabotage the Apollo missions, decades earlier.

Newly discovered documents reveal NASA's secret plan B for failure of the first moon landing. And NASA's Cassini mission unravels a 300-year-old mystery.

Three cosmonauts die mysteriously as they re-enter Earth's atmosphere. Plus, a NASA rover discovers clues that help solve a murder.

Two astronauts trapped in the vacuum of space face an agonising death. Plus, the first close up images of Pluto reveal an alien landscape.

A malfunction on the ISS could poison its crew with a deadly gas. A startling image taken by a NASA probe points to evidence that life could exist on Mars.

A NASA spacecraft suffers a malfunction in orbit - can its lone astronaut make it back to Earth? Plus, new evidence emerges over Yuri Gagarin's mysterious death.

After NASA's New Horizons spacecraft flies by Pluto, it encounters a mysterious object that shuts down the probe's computers. Experts investigate what it could be.

When a black hole looms perilously close to Earth, NASA's finest minds confront the abyss. Secrets of the cosmos unfold, blurring the lines between science and the unknown.

Experts investigate whether the Roswell UFO incident was a Soviet conspiracy masterminded by Stalin, or is the story just another cover-up?

When NASA discovers something strange on Saturn's biggest moon, experts investigate if aliens feeding on the world's electric atmosphere could be the culprit.

Experts investigate if a nearby exoplanet could be the home to an alien civilization after a new discovery confirms that life can thrive on such a world.

A strange discovery by NASA's Mars Curiosity rover suggests the Red Planet was home to an alien nuclear war 300 million years ago. Experts investigate if an extraterrestrial Armageddon transformed the Earth-like world into a wasteland.

Neil Armstrong led an expedition into the Amazon seeking a library apparently made by aliens. Did a close encounter on his moonwalk inspire his quest?

When NASA begins an experiment to communicate with dolphins, experts examine if it's a prelude to making alien contact. Will it have dire consequences?