NASA's Unexplained Files

Astronomers find evidence for alien technology around a distant star. Then, pictures of Pluto show that something might be moving across its surface, and Apollo astronauts see something inexplicable as they approach the moon.

A mission to Mars captures an image of a strange structure. Then, the first Apollo mission records an eerie sighting on the dark side of the moon, and a planet-eating star gives scientists a glimpse of Earth's terrible demise.

Geysers are discovered on a frozen moon, and NASA redirects a probe on a mission to detect evidence of life. Then, an unidentified object is spotted approaching a near-earth asteroid, and a future president witnesses a UFO.

Astronomers detect a potentially habitable planet close to Earth. Then, a discovery at NASA reveals a top-secret military space program, and missions bring back evidence that the moon could have the building blocks for life.

A near collision in space forces two cosmonauts to abort their mission. But a disastrous re-entry leaves them dying in a frozen lake.

Scientists investigate an ancient sighting by Roman soldiers which points to the earth having two moons.

Astronomers studying a distant solar system discover something extraordinary: evidence of an invisible planet orbiting a star.

The Mars Reconnaissance Orbiter captures an image of bizarre streaks on the Martian surface.